Neptune

The eighth planet from the sun, Neptune was the first planet located through mathematical predictions rather than through regular observations of the sky. (Galileo had recorded it as a fixed star during observations with his small telescope in 1612 and 1613.)

When Uranus didn't travel exactly as astronomers expected it to, a French mathematician, Urbain Joseph Le Verrier, proposed the position and mass of another as yet unknown planet that could cause the observed changes to Uranus's orbit. After being ignored by French astronomers, Le Verrier sent his predictions to Johann Gottfried Galle at the Berlin Observatory, who found Neptune on his first night of searching in 1846. Seventeen days later, its largest moon, Triton, was also discovered.
Nearly 2.8 billion miles (4.5 billion kilometers) from the sun, Neptune orbits the sun once every 165 years. It is invisible to the naked eye because of its extreme distance from Earth.
The main axis of Neptune's magnetic field is "tipped over" by about 47 degrees compared with the planet's rotation axis. Like Uranus, whose magnetic axis is tilted about 60 degrees from the axis of rotation, Neptune's magnetosphere undergoes wild variations during each rotation because of this misalignment. The magnetic field of Neptune is about 27 times more powerful than that of Earth.
Neptune's atmosphere extends to great depths, gradually merging into water and other "melted ices" over a heavier, approximately Earth-size solid core. Neptune's blue color is the result of methane in the atmosphere. Uranus's blue-green color is also the result of atmospheric methane, but Neptune is a more vivid, brighter blue, so there must be an unknown component that causes the more intense color that we see. The cause of Neptune's bluish tinge remains a mystery.
Mystery Storm
Despite its great distance from the sun and lower energy input, Neptune's winds are three times stronger than Jupiter's and nine times stronger than Earth's.
In 1989, Voyager 2 tracked a large, oval, dark storm in Neptune's southern hemisphere. This hurricane-like Great Dark Spot was observed to be large enough to contain the entire Earth. It spun counterclockwise and moved westward at almost 750 miles (1,200 kilometers) per hour. (Subsequent images from the Hubble Space Telescope showed no sign of the Great Dark Spot photographed by Voyager. A comparable spot appeared in 1994 in Neptune's northern hemisphere but had disappeared by 1997.) Voyager 2 also photographed clouds casting shadows on a lower cloud deck, enabling scientists to visually measure the altitude differences between the upper and lower cloud decks.
The planet has six rings of varying thicknesses, confirmed by Voyager 2's observations in 1989. Neptune's rings are believed to be relatively young and relatively short-lived.
Neptune has 13 known moons, six of which were discovered by Voyager 2. The largest, Triton, orbits Neptune in a direction opposite to the direction of the planet's rotation. Triton is the coldest body yet visited in our solar system—temperatures on its surface are about -391 degrees Fahrenheit (-235 degrees Celsius). Despite this deep freeze, Voyager 2 discovered geysers spewing icy material upward more than five miles (eight kilometers). Triton's thin atmosphere, also discovered by Voyager, has been seen from Earth several times since, and is growing warmer—although scientists do not yet know why.
Triton Large moon of Neptune

Triton is the largest moon of the planet Neptune, discovered on October 10, 1846, by English astronomer William Lassell. It is the only large moon in the Solar System with a retrograde orbit, which is an orbit in the opposite direction to its planet's rotation. At 2,700 kilometres (1,700 mi) in diameter, it is the seventh-largest moon in the Solar System. Because of its retrograde orbit and composition similar to Pluto's, Triton is thought to have been captured from the Kuiper belt. Triton has a surface of mostly frozen nitrogen, a mostly water ice crust, an icy mantle and a substantial core of rock and metal. The core makes up two-thirds of its total mass. Triton has a mean density of 2.061 grams per cubic centimetre (0.0745 lb/cu in) and is composed of approximately 15–35% water ice.
Triton is one of the few moons in the Solar System known to be geologically active. As a consequence, its surface is relatively young, with a complex geological history revealed in intricate and mysterious cryovolcanic and tectonic terrains. Part of its crust is dotted with geysers thought to erupt nitrogen.Triton has a tenuous nitrogen atmosphere less than 1/70,000 the pressure of Earth's atmosphere at sea level.
 Discover of Triton

Because moons in retrograde orbits cannot have formed out of the same region of the solar nebula as the planets they orbit, it must have been captured from elsewhere. It is suspected that Triton was captured from the Kuiper belt, a ring of small icy objects extending outward from just inside the orbit of Neptune to about 50 AU from the Sun. Thought to be the point of origin for the majority of short-period comets observed from Earth, it is also home to several large, planet-like bodies including Pluto, which is now recognized as the largest in a population of Kuiper belt objects (the plutinos) locked in orbital step with Neptune. Triton is only slightly larger than Pluto and nearly identical in composition, which has led to the hypothesis that the two share a common origin.
In some respects we already saw Pluto long ago even when send a space probe to Pluto was more of a tell of sy fi.
No space probe in been fund let but they keep on bring it up maybe we need to have it where the whole Earth nation fund it. A United Earth Space Probe!We all saw what happen when we send a orbiter  to a planet to spend years just looking around.

Saturn moon-Titan

Titan is a largest moon of Saturn. Its the only natural moon known to have a dense atmosphere.Titan has a diameter about 50% larger than our Moon and is 80% more massive and its 2nd largest moon in our solar system. Titan was the first know moon of Saturn discover by telescope in 1655 by Dutch astronomer Christiaan Huygens and was the 5th moon to be discovered.
Titan is made out of water ice and rocky matter, at the temp on surface of Titan water ice behaves like rock does on the Earth. Like Venus ,Titan atmosphere didn't allow us to understand Titan surface until the space probe called Cassini-Huygens arrive in 2004. By using radar we discover liquid hydrocarbon lakes in Titan polar region. The surface is geologically young; although mountains and several possible cryovolcanoes have been discovered, it is smooth and few impact craters have been found.
Titan atmosphere is made out of Nitrogen and formation of methane and ethane clouds and nitrogen-rich organic smog. It has rain and winds and on its surface there are dunes,river,lakes and seas,but these seas have liquid methane and ethane in them.It also rains liquid methane and ethane.And Titan has its seasons,one season it start raining in the north poles and before it was raining in the south. Remember this rain is made out of liquid methane and ethane. With its liquids (both surface and subsurface) and robust nitrogen atmosphere, Titan's methane cycle is viewed as an analog to Earth's water cycle, although at a much lower temperature.(-220)
Titan was discovered on March 25, 1655, by the Dutch astronomer/physicist Christiaan Huygens. Huygens was inspired by Galileo's discovery of Jupiter's four largest moons in 1610 and his improvements in telescope technology. Christiaan, with the help of his brother Constantijn Huygens, Jr., began building telescopes around 1650. Christiaan Huygens discovered this first observed moon orbiting Saturn with the first telescope they built.
He named it simply Saturni Luna (or Luna Saturni, Latin for "Saturn's moon"), publishing in the 1655 tract De Saturni Luna Observatio Nova. After Giovanni Domenico Cassini published his discoveries of four more moons of Saturn between 1673 and 1686, astronomers fell into the habit of referring to these and Titan as Saturn I through V (with Titan then in fourth position). Other early epithets for Titan include "Saturn's ordinary satellite".Titan is officially numbered Saturn VI because after the 1789 discoveries the numbering scheme was frozen to avoid causing any more confusion (Titan having borne the numbers II and IV as well as VI). Numerous small moons have been discovered closer to Saturn since then.
The name Titan, and the names of all seven satellites of Saturn then known, came from John Herschel (son of William Herschel, discoverer of Mimas and Enceladus) in his 1847 publication Results of Astronomical Observations Made at the Cape of Good Hope. He suggested the names of the mythological Titans (Ancient Greek: Τῑτάν), sisters and brothers of Cronus, the Greek Saturn. In Greek mythology, the Titans were a race of powerful deities, descendants of Gaia and Uranus, that ruled during the legendary Golden Age.

Titan orbits Saturn once every 15 days and 22 hours. Like many of the other satellites of the gas giants and the Moon, its rotational period is identical to its orbital period; Titan is thus tidally locked in synchronous rotation with Saturn, and always shows one face to the planet. Because of this, there is a sub-Saturnian point on its surface, from which the planet would appear to hang directly overhead. Longitudes on Titan are measured westward from the meridian passing through this point.Its orbital eccentricity is 0.0288, and the orbital plane is inclined 0.348 degrees relative to the Saturnian equator.Viewed from Earth, Titan reaches an angular distance of about 20 Saturn radii from Saturn and subtends a disk 0.8 arcseconds in diameter.
The small, irregularly shaped satellite Hyperion is locked in a 3:4 orbital resonance with Titan. A "slow and smooth" evolution of the resonance—in which Hyperion would have migrated from a chaotic orbit—is considered unlikely, based on models. Hyperion probably formed in a stable orbital island, whereas the massive Titan absorbed or ejected bodies that made close approaches.

The moons of Jupiter and Saturn are thought to have formed through co-accretion, a similar process to that believed to have formed the planets in the Solar System. As the young gas giants formed, they were surrounded by discs of material that gradually coalesced into moons. However, whereas Jupiter possesses four large satellites in highly regular, planet-like orbits, Titan overwhelmingly dominates Saturn's system and possesses a high orbital eccentricity not immediately explained by co-accretion alone. A proposed model for the formation of Titan is that Saturn's system began with a group of moons similar to Jupiter's Galilean satellites, but that they were disrupted by a series of giant impacts, which would go on to form Titan. Saturn's mid-sized moons, such as Iapetus and Rhea, were formed from the debris of these collisions. Such a violent beginning would also explain Titan's orbital eccentricity.
Atmosphere
Titan is the only known moon with more than a trace of atmosphere. Its atmosphere is the only nitrogen-rich dense atmosphere in the Solar System aside from Earth's. Observations of the atmosphere, made in 2004 by Cassini, suggest that Titan is a "super rotator", like Venus, with an atmosphere that rotates much faster than its surface. Observations from the Voyager space probes have shown that the Titanian atmosphere is denser than Earth's, with a surface pressure about 1.45 times that of Earth's. Titan's atmosphere is about 1.19 times as massive as Earth's overall, or about 7.3 times more massive on a per surface area basis. It supports opaque haze layers that block most visible light from the Sun and other sources and renders Titan's surface features obscure. Titan's lower gravity means that its atmosphere is far more extended than Earth's.The atmosphere of Titan is opaque at many wavelengths and a complete reflectance spectrum of the surface is impossible to acquire from orbit.It was not until the arrival of the Cassini–Huygens mission in 2004 that the first direct images of Titan's surface were obtained.
The atmospheric composition in the stratosphere is 98.4% nitrogen with the remaining 1.6% composed mostly of methane (1.4%) and hydrogen (0.1–0.2%). There are trace amounts of other hydrocarbons, such as ethane, diacetylene, methylacetylene, acetylene and propane, and of other gases, such as cyanoacetylene, hydrogen cyanide, carbon dioxide, carbon monoxide, cyanogen, argon and helium. The hydrocarbons are thought to form in Titan's upper atmosphere in reactions resulting from the breakup of methane by the Sun's ultraviolet light, producing a thick orange smog.Titan spends 95% of its time within Saturn's magnetosphere, which may help shield Titan from the solar wind.
Energy from the Sun should have converted all traces of methane in Titan's atmosphere into more complex hydrocarbons within 50 million years — a short time compared to the age of the Solar System. This suggests that methane must be somehow replenished by a reservoir on or within Titan itself. The ultimate origin of the methane in Titan's atmosphere may be its interior, released via eruptions from cryovolcanoes.
On April 3, 2013, NASA reported that complex organic chemicals could arise on Titan based on studies simulating the atmosphere of Titan.
On June 6, 2013, scientists at the IAA-CSIC reported the detection of polycyclic aromatic hydrocarbons in the upper atmosphere of Titan.

Titan is the only moon left that form with Saturn,On Jupiter 4 main moon form but for some reason Titan when crazy and by time its was done it was the only one left. The other moon are from moon that got destroy or capture body for beyond Saturn.It orbit is very crazy!
It surface until recent visit from Cassini give us more info about it surface.But before it visit the Hubble space telescope give us so info. But it took sending a probe through Titan atmosphere and it send back photos of it surface. More photo was expected but a malfunction with Cassini receiver only 1 channel out of two was working right the rest of the photo was send but Cassini could hear it. The probe landed on it surface and last 90 mins on the surface before the batteries give out.

More info about the lander. It has these instruments
Huygens Atmospheric Structure Instrument (HASI)This instrument contains a suite of sensors that measured the physical and electrical properties of Titan's atmosphere. Accelerometers measured forces in all three axes as the probe descended through the atmosphere. With the aerodynamic properties of the probe already known, it was possible to determine the density of Titan's atmosphere and to detect wind gusts. The probe was designed so that in the event of a landing on a liquid surface, its motion due to waves would also have been measurable. Temperature and pressure sensors measured the thermal properties of the atmosphere. The Permittivity and Electromagnetic Wave Analyzer component measured the electron and ion (i.e., positively charged particle) conductivities of the atmosphere and searched for electromagnetic wave activity. On the surface of Titan, the electrical conductivity and permittivity (i.e., the ratio of electric displacement field to its electric field) of the surface material was measured. The HASI subsystem also contains a microphone, which was used to record any acoustic events during probe's descent and landing;this was the first time in history that audible sounds from another planetary body had been recorded.
Doppler Wind Experiment (DWE)
This experiment used an ultra-stable oscillator to improve communication with the probe by giving it a very stable carrier frequency. This instrument was also used to measure the wind speed in Titan's atmosphere by measuring the Doppler shift in the carrier signal. The swinging motion of the probe beneath its parachute due to atmospheric properties may also have been detected. Failure of ground controllers to turn on the receiver in the Cassini orbiter caused the loss of this data. Earth-based radio telescopes were able to reconstruct some of it. Measurements started 150 kilometres above Titan's surface, where Huygens was blown eastwards at more than 400 kilometres per hour, agreeing with earlier measurements of the winds at 200 kilometres altitude, made over the past few years using telescopes. Between 60 and 80 kilometres, Huygens was buffeted by rapidly fluctuating winds, which are thought to be vertical wind shear. At ground level, the Earth-based doppler shift and VLBI measurements show gentle winds of a few metres per second, roughly in line with expectations.
Descent Imager/Spectral Radiometer (DISR)
As Huygens was primarily an atmospheric mission, the DISR instrument was optimized to study the radiation balance inside Titan's atmosphere. Its visible and infrared spectrometers and violet photometers measured the up- and downward radiant flux from an altitude of 145 kilometers down to the surface. Solar aureole cameras measured how scattering by aerosols varies the intensity directly around the Sun. Three imagers, sharing the same CCD, periodically imaged a swath of around 30 degrees wide, ranging from almost nadir to just above the horizon. Aided by the slowly spinning probe they would build up a full mosaic of the landing site, which, surprisingly, became clearly visible only below 25 kilometers altitude. All measurements were timed by aid of a shadow bar, which would tell DISR when the Sun had passed through the field of view. Unfortunately, this scheme was upset by the fact that Huygens rotated in a direction opposite to that expected. Just before landing a lamp was switched on to illuminate the surface, which enabled measurements of the surface reflectance at wavelengths which are completely blocked out by atmospheric methane absorption.
DISR was developed at the Lunar and Planetary Laboratory at the University of Arizona under the direction of Martin Tomasko, with several European institutes contributing to the hardware.
Gas Chromatograph Mass Spectrometer (GC/MS)
This instrument is a versatile gas chemical analyzer that was designed to identify and measure chemicals in Titan's atmosphere. It was equipped with samplers that were filled at high altitude for analysis. The mass spectrometer, a high-voltage quadrupole, collected data to build a model of the molecular masses of each gas, and a more powerful separation of molecular and isotopic species was accomplished by the gas chromatograph.During descent, the GC/MS also analyzed pyrolysis products (i.e., samples altered by heating) passed to it from the Aerosol Collector Pyrolyser. Finally, the GC/MS measured the composition of Titan's surface. This investigation was made possible by heating the GC/MS instrument just prior to impact in order to vaporize the surface material upon contact. The GC/MS was developed by the Goddard Space Flight Center and University of Michigan's Space Physics Research Lab.
Aerosol Collector and Pyrolyser (ACP)
The ACP experiment drew in aerosol particles from the atmosphere through filters, then heated the trapped samples in ovens (using the process of pyrolysis) to vaporize volatiles and decompose the complex organic materials. The products were flushed along a pipe to the GC/MS instrument for analysis. Two filters were provided to collect samples at different altitudes.The ACP was developed by a (French) ESA team at the Laboratoire Inter-Universitaire des Systèmes Atmosphériques (LISA).
Surface Science Package (SSP)
The SSP contained a number of sensors designed to determine the physical properties of Titan's surface at the point of impact, whether the surface was solid or liquid. An acoustic sounder, activated during the last 100 meters of the descent, continuously determined the distance to the surface, measuring the rate of descent and the surface roughness (e.g., due to waves). The instrument was designed so that if the surface were liquid, the sounder would measure the speed of sound in the "ocean" and possibly also the subsurface structure (depth). During descent, measurements of the speed of sound gave information on atmospheric composition and temperature, and an accelerometer recorded the deceleration profile at impact, indicating the hardness and structure of the surface. A tilt sensor measured pendulum motion during the descent and was also designed to indicate the probe's attitude after landing and show any motion due to waves. If the surface had been liquid, other sensors would also have measured its density, temperature, thermal conductivity, heat capacity, electrical properties (permittivity and conductivity) and refractive index (using a critical angle refractometer). A penetrometer instrument, that protruded 55 mm past the bottom of the Huygens descent module, was used to create a penetrometer trace as Huygens landed on the surface by measuring the force exerted on the instrument by the surface as the instrument broke though the surface and was pushed down into the planet by the force of the probe landing itself. The trace shows this force as a function of time over a period of about 400 ms. The trace has an initial spike which suggests that the instrument hit one of the icy pebbles on the surface photographed by the DISR camera.
The Huygens SSP was developed by the Space Sciences Department of the University of Kent and the Rutherford Appleton Laboratory Space Science Department under the direction of Professor John Zarnecki. The SSP research and responsibility transferred to the Open University when John Zarnecki transferred in 2000.





More about its surface
The surface of Titan has been described as "complex, fluid-processed, [and] geologically young". Titan has been around since the Solar System's formation, but its surface is much younger, between 100 million and 1 billion years old. Geological processes may have reshaped Titan's surface. Titan's atmosphere is twice as thick as the Earth's, making it difficult for astronomical instruments to image its surface in the visible light spectrum.The Cassini spacecraft is using infrared instruments, radar altimetry and synthetic aperture radar (SAR) imaging to map portions of Titan during its close fly-bys of Titan. The first images revealed a diverse geology, with both rough and smooth areas. There are features that seem volcanic in origin, which probably disgorge water mixed with ammonia. There are also streaky features, some of them hundreds of kilometers in length, that appear to be caused by windblown particles.Examination has also shown the surface to be relatively smooth; the few objects that seem to be impact craters appeared to have been filled in, perhaps by raining hydrocarbons or volcanoes. Radar altimetry suggests height variation is low, typically no more than 150 meters. Occasional elevation changes of 500 meters have been discovered and Titan has mountains that sometimes reach several hundred meters to more than 1 kilometer in height.
Titan's surface is marked by broad regions of bright and dark terrain. These include Xanadu, a large, reflective equatorial area about the size of Australia. It was first identified in infrared images from the Hubble Space Telescope in 1994, and later viewed by the Cassini spacecraft. The convoluted region is filled with hills and cut by valleys and chasms.It is criss-crossed in places by dark lineaments—sinuous topographical features resembling ridges or crevices. These may represent tectonic activity, which would indicate that Xanadu is geologically young. Alternatively, the lineaments may be liquid-formed channels, suggesting old terrain that has been cut through by stream systems. There are dark areas of similar size elsewhere on Titan, observed from the ground and by Cassini; it had been speculated that these are methane or ethane seas, but Cassini observations seem to indicate otherwise. You see at certain infrared wave you can take a photo from Cassini but the SAR give more of what is on that surface
Liquids
The possibility of hydrocarbon seas on Titan was first suggested based on Voyager 1 and 2 data that showed Titan to have a thick atmosphere of approximately the correct temperature and composition to support them, but direct evidence was not obtained until 1995 when data from Hubble and other observations suggested the existence of liquid methane on Titan, either in disconnected pockets or on the scale of satellite-wide oceans, similar to water on Earth.
The Cassini mission confirmed the former hypothesis, although not immediately. When the probe arrived in the Saturnian system in 2004, it was hoped that hydrocarbon lakes or oceans might be detectable by reflected sunlight from the surface of any liquid bodies, but no specular reflections were initially observed. Near Titan's south pole, an enigmatic dark feature named Ontario Lacus was identified (and later confirmed to be a lake). A possible shoreline was also identified near the pole via radar imagery.Following a flyby on July 22, 2006, in which the Cassini spacecraft's radar imaged the northern latitudes (that were then in winter), a number of large, smooth (and thus dark to radar) patches were seen dotting the surface near the pole. Based on the observations, scientists announced "definitive evidence of lakes filled with methane on Saturn's moon Titan" in January 2007.The Cassini–Huygens team concluded that the imaged features are almost certainly the long-sought hydrocarbon lakes, the first stable bodies of surface liquid found outside of Earth. Some appear to have channels associated with liquid and lie in topographical depressions. The liquid erosion features appear to be a very recent occurrence: channels in some regions have created surprisingly little erosion, suggesting erosion on Titan is extremely slow, or some other recent phenomena may have wiped out older riverbeds and landforms. Overall, the Cassini radar observations have shown that lakes cover only a few percent of the surface, making Titan much drier than Earth. Although most of the lakes are concentrated near the poles (where the relative lack of sunlight prevents evaporation), a number of long-standing hydrocarbon lakes in the equatorial desert regions have also been discovered, including one near the Huygens landing site in the Shangri-La region, which is about half the size of Utah's Great Salt Lake. The equatorial lakes are probably "oases", i.e. the likely supplier is underground aquifers.
In June 2008, the Visual and Infrared Mapping Spectrometer on Cassini confirmed the presence of liquid ethane beyond doubt in Ontario Lacus. On December 21, 2008, Cassini passed directly over Ontario Lacus and observed specular reflection in radar. The strength of the reflection saturated the probe's receiver, indicating that the lake level did not vary by more than 3 mm (implying either that surface winds were minimal, or the lake's hydrocarbon fluid is viscous).
Specular reflections are indicative of a smooth, mirror-like surface, so the observation corroborated the inference of the presence of a large liquid body drawn from radar imaging. The observation was made soon after the north polar region emerged from 15 years of winter darkness.
On July 8, 2009, Cassini's VIMS observed a specular reflection indicative of a smooth, mirror-like surface, off what today is called Jingpo Lacus, a lake in the north polar region shortly after the area emerged from 15 years of winter darkness.
During a flyby on 26 September 2012, Cassini's radar detected in Titan's northern polar region what is likely a river with a length of more than 400 kilometers. It has been compared with the much larger Nile river on Earth. This feature ends in Ligeia Mare.
During six flybys of Titan from 2006 to 2011, Cassini gathered radio-metric tracking and optical navigation data from which investigators could roughly infer Titan's changing shape. The density of Titan is consistent with a body that is about 60% rock and 40% water. The team's analyses suggest that Titan's surface can rise and fall by up to 10 metres during each orbit. That degree of warping suggests that Titan's interior is relatively deformable, and that the most likely model of Titan is one in which an icy shell dozens of kilometres thick floats atop a global ocean. The team's findings, together with the results of previous studies, hint that Titan's ocean may lie no more than 100 km below its surface.
Impact craters

Radar, SAR and imaging data from Cassini have revealed few impact craters on Titan's surface. These impacts appear to be relatively young, compared to Titan's age. The few impact craters discovered include a 440 km wide two-ring impact basin named Menrva seen by Cassini's ISS as a bright-dark concentric pattern.A smaller, 60 km wide, flat-floored crater named Sinlap and a 30 km crater with a central peak and dark floor named Ksa have also been observed. Radar and Cassini imaging have also revealed a number of "crateriforms", circular features on the surface of Titan that may be impact related, but lack certain features that would make identification certain. For example, a 90 km wide ring of bright, rough material known as Guabonito has been observed by Cassini.This feature is thought to be an impact crater filled in by dark, windblown sediment. Several other similar features have been observed in the dark Shangri-la and Aaru regions. Radar observed several circular features that may be craters in the bright region Xanadu during Cassini's April 30, 2006 flyby of Titan.
Like on the Earth many of the crater on Titan where change by erosion.They are fill in by cryovolcanic lava and wind bore dust. Titan thick atmosphere protect Titan from the small one and only the big one get through. Like every object in our solar system Titan was hit but they was cover up like they are on the Earth by almost the simple processes_wind ,water(what pass for water on Titan)(I already give you the answer I see if you reading it>>>
Cryovolcanism is cause by Saturn pushing and pulling of Titan and is this tidal flexing plus radioactive matter in the core give this moon the power to for cryovolcano. This lava is made out of a mix of water and ammonia(this mix with water to change its freezing point),so on the surface it would ozz around like lava on the Earth covering everything around. We had never saw a volcano on Titan but radar had show area around what look like volcano on the radar map had change and they remap the area and it sow a smooth area where it used to be a rocky type of surface. We need a long lasting probe on the surface to look for volcano and other stuff.But no are plan or funded

Observation and exploration
Titan is never visible to the naked eye, but can be observed through small telescopes or strong binoculars. Amateur observation is difficult because of the proximity of Titan to Saturn's brilliant globe and ring system; an occulting bar, covering part of the eyepiece and used to block the bright planet, greatly improves viewing.Titan has a maximum apparent magnitude of +8.2, and mean opposition magnitude 8.4. This compares to +4.6 for the similarly sized Ganymede, in the Jovian system.
Observations of Titan prior to the space age were limited. In 1907 Spanish astronomer Josep Comas Solá observed limb darkening of Titan, the first evidence that the body has an atmosphere. In 1944 Gerard P. Kuiper used a spectroscopic technique to detect an atmosphere of methane.
The first probe to visit the Saturnian system was Pioneer 11 in 1979, which confirmed that Titan was probably too cold to support life. It took images of Titan, including Titan and Saturn together in mid to late 1979.The quality was soon surpassed by the two Voyagers, but Pioneer 11 provided data for everyone to prepare with.
Titan was examined by both Voyager 1 and 2 in 1980 and 1981, respectively. Voyager 1's course was diverted specifically to make a closer pass of Titan. Unfortunately, the craft did not possess any instruments that could penetrate Titan's haze, an unforeseen factor. Many years later, intensive digital processing of images taken through Voyager 1's orange filter did reveal hints of the light and dark features now known as Xanadu and Shangri-la, but by then they had already been observed in the infrared by the Hubble Space Telescope. Voyager 2 took only a cursory look at Titan. The Voyager 2 team had the option of steering the spacecraft to take a detailed look at Titan or to use another trajectory that would allow it to visit Uranus and Neptune. Given the lack of surface features seen by Voyager 1, the latter plan was implemented. Which was good but they could had allow a not so close the Titan and maybe send it to Pluto but they decide to see if the voyager could see it surface.
Cassini–Huygens(it was the size of a small bus and weight over 5000lb) this why it took so long just to get there,they just got it off the Earth and had to do many flyby of Earth Venus and jupiter each time it give it a big push but it was Jupiter that got it there with a big,big push.In the past I done a small report about his space probe.
Even with the data provided by the Voyagers, Titan remained a body of mystery—a planet-like satellite shrouded in an atmosphere that makes detailed observation difficult. The intrigue that had surrounded Titan since the 17th-century observations of Christiaan Huygens and Giovanni Cassini was gratified by a spacecraft named in their honor.

The Cassini–Huygens spacecraft reached Saturn on July 1, 2004, and has begun the process of mapping Titan's surface by radar. A joint project of the European Space Agency (ESA) and NASA, Cassini–Huygens has proved a very successful mission. The Cassini probe flew by Titan on October 26, 2004, and took the highest-resolution images ever of Titan's surface, at only 1,200 km, discerning patches of light and dark that would be invisible to the human eye from the Earth. Huygens landed on Titan on January 14, 2005, discovering that many of its surface features seem to have been formed by flowing fluids at some point in the past. On July 22, 2006, Cassini made its first targeted, close fly-by at 950 km from Titan; the closest flyby was at 880 km on June 21, 2010. Present liquid on the surface has been found in abundance in the north polar region, in the form of many lakes and seas discovered by Cassini. Titan is the most distant body from Earth and the second moon in the Solar System to have a space probe land on its surface.
Huygens landing site
On January 14, 2005, the Huygens probe landed on the surface of Titan, just off the easternmost tip of a bright region now called Adiri. The probe photographed pale hills with dark "rivers" running down to a dark plain. Current understanding is that the hills (also referred to as highlands) are composed mainly of water ice. Dark organic compounds, created in the upper atmosphere by the ultraviolet radiation of the Sun, may rain from Titan's atmosphere. They are washed down the hills with the methane rain and are deposited on the plains over geological time scales.
After landing, Huygens photographed a dark plain covered in small rocks and pebbles, which are composed of water ice.The two rocks just below the middle of the image on the right are smaller than they may appear: the left-hand one is 15 centimeters across, and the one in the center is 4 centimeters across, at a distance of about 85 centimeters from Huygens. There is evidence of erosion at the base of the rocks, indicating possible fluvial activity. The surface is darker than originally expected, consisting of a mixture of water and hydrocarbon ice. The assumption is that the "soil" visible in the images is precipitation from the hydrocarbon haze above.
In March 2007, NASA, ESA, and COSPAR decided to name the Huygens landing site the Hubert Curien Memorial Station in memory of the former president of the ESA.
Future missions
Because of limit cash for space, there was few of them on the drawing board
The Titan Saturn System Mission (TSSM) is a joint NASA/ESA proposal for exploration of Saturn's moons.It envisions a hot-air balloon floating in Titan's atmosphere for six months. It was competing against the Europa Jupiter System Mission (EJSM) proposal for funding. In February 2009 it was announced that ESA/NASA had given the EJSM mission priority ahead of the TSSM, although TSSM was still considered for a later launch date. Since NASA's departure from the program in 2012, these plans were put on hold.
There has also been a proposal for a Titan Mare Explorer (TiME), which would be a low-cost lander that would splash down in a lake near Titan's north pole and float on the surface of the lake for 3 to 6 months. It could launch as early as 2016 and arrive in 2023. In 2012, however, NASA chose to fund the Mars probe InSight instead of TiME, rendering the Titan probe's future uncertain.
Another lake lander project was proposed in late 2012 in Europe. The concept probe is called Titan Lake In-situ Sampling Propelled Explorer (TALISE). The major difference with the TiME probe would be a propulsion system.
Another proposed mission to Titan is the Aerial Vehicle for In-situ and Airborne Titan Reconnaissance (AVIATR), which is an unmanned plane (or drone) which would fly through Titan's atmosphere and take high-definition images of the surface of Titan.

its sad in a way,we find all kind of cash for build place for them to play sport or we find money for weapon system or etc but don't have the cash to do this. Every nation can give afew percent of their gross nation product and created The Earth Space Probe Center. They can start with something like this and than go on and on maybe even one day fund going to Mars and set up a city that would get bigger and bigger... Oh well...Here a look into what will happen one day
Future conditions
Conditions on Titan could become far more habitable in the far future. Five billion years from now, as the Sun becomes a red giant, surface temperatures could rise enough for Titan to support liquid water on its surface making it habitable. As the Sun's ultraviolet output decreases, the haze in Titan's upper atmosphere will be depleted, lessening the anti-greenhouse effect on the surface and enabling the greenhouse created by atmospheric methane to play a far greater role. These conditions together could create a habitable environment, and could persist for several hundred million years. This was sufficient time for simple life to evolve on Earth, although the presence of ammonia on Titan would cause chemical reactions to proceed more slowly.This will happen even without us!

Enceladus

Moon of Saturn

Enceladus is the sixth-largest of the moons of Saturn. It was discovered in 1789 by William Herschel. Enceladus seems to have liquid water under its icy surface. Cryovolcanoes at the south pole shoot large jets of water vapor, other volatiles and some solid particles (ice crystal, NaCl etc) into space . Some of this water falls back onto the moon as "snow", some of it adds to Saturn's rings, and some of it reaches Saturn. The whole of Saturn's E ring is believed to have been made from these ice particles. Because of the apparent water at or near the surface, Enceladus may be one of the best places for humans to look for extraterrestrial life. By contrast, the water thought to be on Jupiter's moon Europa is locked under a very thick layer of surface ice.
Until the two Voyager spacecraft passed near it in the early 1980s very little was known about this small moon besides the identification of water ice on its surface. The Voyagers showed that the diameter of Enceladus is only 310 mi), about a tenth of that of Saturn's largest moon, Titan, and that it reflects almost all of the sunlight that strikes it. Voyager 1 found that Enceladus orbited in the densest part of Saturn's diffuse E ring, indicating a possible association between the two, while Voyager 2 revealed that despite the moon's small size, it had a wide range of terrains ranging from old, heavily cratered surfaces to young, tectonically deformed terrain, with some regions with surface ages as young as 100 million years old.
In 2005 the Cassini spacecraft performed several close flybys of Enceladus, revealing the moon's surface and environment in greater detail. In particular, the probe discovered a water-rich plume venting from the moon's south polar region. This discovery, along with the presence of escaping internal heat and very few (if any) impact craters in the south polar region, shows that Enceladus is geologically active today. Moons in the extensive satellite systems of gas giants often become trapped in orbital resonances that lead to forced libration or orbital eccentricity; proximity to Saturn can then lead to tidal heating of Enceladus's interior, offering a possible explanation for the activity.
Exploration

Size comparison of Earth and Enceladus,if you compare it to Saturn you wouldn't be able to see it,the dot would be so small
Enceladus was discovered by Fredrick William Herschel on August 28, 1789, during the first use of his new 1.2 m telescope, then the largest in the world. Herschel first observed Enceladus in 1787, but in his smaller, 16.5 cm telescope, the moon was not recognized.Its faint apparent magnitude (+11.7m) and its proximity to much brighter Saturn and its rings make Enceladus difficult to observe from Earth, requiring a telescope with a mirror of 15–30 cm in diameter, depending on atmospherical conditions and light pollution. Like many Saturnian satellites discovered prior to the Space Age, Enceladus was first observed during a Saturnian equinox, when Earth is within the ring plane; at such times, the reduction in glare from the rings makes the moons easier to observe.

(Dramatic plumes, both large and small, spray water ice out from many locations along the famed "tiger stripes" near the south pole of Saturn's moon Enceladus. From right to left, the four major stripes are Damascus, Baghdad, Cairo and Alexandria sulci.)
Prior to the Voyager missions the view of Enceladus improved little from the dot first observed by Herschel. Only its orbital characteristics were known, with estimations of its mass, density and albedo.
The two Voyager spacecraft obtained the first close-up images of Enceladus. Voyager 1 was the first to fly past Enceladus, at a distance of 202,000 km on November 12, 1980. Images acquired from this distance had very poor spatial resolution, but revealed a highly reflective surface devoid of impact craters, indicating a youthful surface.Voyager 1 also confirmed that Enceladus was embedded in the densest part of Saturn's diffuse E-ring. Combined with the apparent youthful appearance of the surface, Voyager scientists suggested that the E-ring consisted of particles vented from Enceladus's surface.
Dramatic plumes, both large and small, spray water ice out from many locations along the famed "tiger stripes" near the south pole of Saturn's moon Enceladus. From right to left, the four major stripes are Damascus, Baghdad, Cairo and Alexandria sulci.
Voyager 2 passed closer to Enceladus (87,010 km) on August 26, 1981, allowing much higher-resolution images of this satellite.[25] These images revealed the youthful nature of much of its surface, They also revealed a surface with different regions with vastly different surface ages, with a heavily cratered mid- to high-northern latitude region, and a lightly cratered region closer to the equator. This geologic diversity contrasts with the ancient, heavily cratered surface of Mimas, another moon of Saturn slightly smaller than Enceladus. The geologically youthful terrains came as a great surprise to the scientific community, because no theory was then able to predict that such a small (and cold, compared to Jupiter's highly active moon Io) celestial body could bear signs of such activity. However, Voyager 2 failed to determine whether Enceladus was currently active or whether it was the source of the E-ring.

The answer to these and other mysteries had to wait until the arrival of the Cassini spacecraft on July 1, 2004, when it went into orbit around Saturn. Given the results from the Voyager 2 images, Enceladus was considered a priority target by the Cassini mission planners, and several targeted flybys within 1,500 km of the surface were planned as well as numerous, "non-targeted" opportunities within 100,000 km of Enceladus. The flybys have yielded significant information concerning Enceladus's surface, as well as the discovery of water vapor and complex hydrocarbons venting from the geologically active South Polar Region. These discoveries prompted the adjustment of Cassini's flight plan to allow closer flybys of Enceladus, including an encounter in March 2008 which took the probe to within 52 km of the moon's surface.The extended mission for Cassini included seven close flybys of Enceladus between July 2008 and July 2010, including two passes at only 50 km in the later half of 2008.
The discoveries Cassini has made at Enceladus have prompted several studies into follow-up missions. In 2007 NASA performed a concept study for a mission that would orbit Enceladus and would perform a detailed examination of the south polar plumes.The concept was not selected for further study.The European Space Agency also recently explored plans to send a probe to Enceladus in a mission to be combined with studies of Titan.
The Titan Saturn System Mission (TSSM) is a joint NASA/ESA proposal for exploration of Saturn's moons, including Enceladus. TSSM was competing against the Europa Jupiter System Mission (EJSM) proposal for funding. In February 2009 it was announced that ESA/NASA had given the EJSM mission priority ahead of TSSM,although TSSM will continue to be studied for a later launch date.

Size and shape
Enceladus is a relatively small moon, with a mean diameter of 314 mi), only one-seventh the diameter of Earth's own Moon.
Its mass and diameter make Enceladus the sixth most massive and largest satellite of Saturn, after Titan (5150 km), Rhea (1530 km), Iapetus (1440 km), Dione (1120 km) and Tethys (1050 km). It is also one of the smallest of Saturn's spherical satellites, since all smaller satellites except Mimas (390 km) have an irregular shape.
Enceladus is a scalene ellipsoid in shape; its diameters, calculated from pictures taken by Cassini's ISS (Imaging Science Subsystem) instrument, are 513 km between the sub- and anti-Saturnian poles, 503 km between the leading and trailing poles, and 497 km between the north and south poles. This is the most stable orientation, with the moon's rotation along the short axis, and the long axis aligned radially away from Saturn.
Surface


A very young face for a very small moon.
 Voyager 2, in August 1981, was the first spacecraft to observe the surface in detail. Examination of the resulting highest-resolution mosaic reveals at least five different types of terrain, including several regions of cratered terrain, regions of smooth (young) terrain, and lanes of ridged terrain often bordering the smooth areas. In addition, extensive linear cracks and scarps were observed. Given the relative lack of craters on the smooth plains, these regions are probably less than a few hundred million years old. Accordingly, Enceladus must have been recently active with "water volcanism" or other processes that renew the surface. The fresh, clean ice that dominates its surface gives Enceladus probably the most reflective surface of any body in the Solar System with a visual geometric albedo of 1.38. Because it reflects so much sunlight, the mean surface temperature at noon only reaches −198 °C (somewhat colder than other Saturnian satellites).
Observations during three flybys by Cassini on February 17, March 9, and July 14 of 2005 revealed Enceladus's surface features in much greater detail than the Voyager 2 observations. For example, the smooth plains observed by Voyager 2 resolved into relatively crater-free regions filled with numerous small ridges and scarps. In addition, numerous fractures were found within the older, cratered terrain, suggesting that the surface has been subjected to extensive deformation since the craters were formed.Finally, several additional regions of young terrain were discovered in areas not well-imaged by either Voyager spacecraft, such as the bizarre terrain near the south pole.
Impact craters
Impact cratering is a common occurrence on many Solar System bodies. Much of Enceladus's surface is covered with craters at various densities and levels of degradation. From Voyager 2 observations, three different units of cratered topography were identified on the basis of their crater densities, from ct1 and ct2, both containing numerous 10–20 km-wide craters though differing in the degree of deformation, to cp consisting of lightly cratered plains.This subdivision of cratered terrains on the basis of crater density (and thus surface age) suggests that Enceladus has been resurfaced in multiple stages.
Recent Cassini observations have provided a much closer look at the ct2 and cp cratered units. These high-resolution observations, reveal that many of Enceladus's craters are heavily deformed through viscous relaxation and fracturing. Viscous relaxation allows gravity, over geologic time scales, to deform craters and other topographic features formed in water ice, reducing the amount of topography over time. The rate at which this occurs is dependent on the temperature of the ice: warmer ice is easier to deform than colder, stiffer ice. Viscously relaxed craters tend to have domed floors, or are recognized as craters only by a raised, circular rim . Dunyazad, the large crater seen in Figure 8 just left of top center, is a prime example of a viscously relaxed crater on Enceladus, with a prominent domed floor. In addition, many craters on Enceladus have been heavily modified by tectonic fractures. The 10-km-wide crater right of bottom center in Figure 8 is a prime example: thin fractures, several hundred meters to a kilometer wide, have heavily altered the crater's rim and floor. Nearly all craters on Enceladus thus far imaged by Cassini in the ct2 unit show signs of tectonic deformation.

Tectonics
Voyager 2 found several types of tectonic features on Enceladus, including troughs, scarps, and belts of grooves and ridges.Recent results from Cassini suggest that tectonism is the dominant deformation style on Enceladus. One of the more dramatic types of tectonic features found on Enceladus are rifts. These canyons can be up to 200 km long, 5–10 km wide, and one km deep. Figure 7 Below shows a typical large fracture on Enceladus cutting across older, tectonically deformed terrain. Another example can be seen running along the bottom of the frame in Figure 8. Such features appear relatively young, as they cut across other tectonic features and have sharp topographic relief with prominent outcrops along the cliff faces.

Another evidence of tectonism on Enceladus is grooved terrain, consisting of lanes of curvilinear grooves and ridges. These bands, first discovered by Voyager 2, often separate smooth plains from cratered regions.An example of this terrain type can be seen in 10 (in this case, a feature known as the Samarkand Sulci). Grooved terrains such as the Samarkand Sulci are reminiscent of grooved terrain on Ganymede. However, unlike those seen on Ganymede, grooved topography on Enceladus is generally much more complex. Rather than parallel sets of grooves, these lanes can often appear as bands of crudely aligned, chevron-shaped features. In other areas, these bands appear to bow upwards with fractures and ridges running the length of the feature. Cassini observations of the Samarkand Sulci have revealed intriguing dark spots (125 and 750 m wide), which appear to run parallel to narrow fractures. Currently, these spots are interpreted as collapse pits within these ridged plain belts.

Atmosphere
The first Cassini flybys of Enceladus revealed that it has a significant atmosphere compared to the other moons of Saturn besides Titan. The source of the atmosphere may be volcanism, geysers, or gasses escaping from the surface or the interior.The atmosphere of Enceladus is composed of 91% water vapor, 4% nitrogen, 3.2% carbon dioxide, and 1.7% methane.

Cryovolcanism


(Figure 13: Heat map (within white box) of the thermally active field of fractures, measured at wavelengths between 12 and 16 micrometers, superimposed on a visual-light image. One of the four fractures (right) was only partially imaged.)
Following the Voyager encounters with Enceladus in the early 1980s, scientists postulated that the moon may be geologically active based on its young, reflective surface and location near the core of the E ring. Based on the connection between Enceladus and the E ring, it was thought that Enceladus was the source of material in the E ring, perhaps through venting of water vapor from Enceladus's interior. However, the Voyagers failed to provide conclusive evidence that Enceladus is active today.
Thanks to data from a number of instruments on the Cassini spacecraft in 2005, cryovolcanism, where water and other volatiles are the materials erupted instead of silicate rock, has been discovered on Enceladus. The first Cassini sighting of a plume of icy particles above Enceladus's south pole came from the Imaging Science Subsystem (ISS) images taken in January and February 2005,though the possibility of the plume being a camera artifact stalled an official announcement. Data from the magnetometer instrument during the February 17, 2005 encounter provided a hint that the feature might be real when it found evidence for an atmosphere at Enceladus. The magnetometer observed an increase in the power of ion cyclotron waves near Enceladus. These waves are produced by the interaction of ionized particles and magnetic fields, and the frequency of the waves can be used to identify the composition, in this case ionized water vapor.During the next two encounters, the magnetometer team determined that gases in Enceladus's atmosphere are concentrated over the south polar region, with atmospheric density away from the pole being much lower.The Ultraviolet Imaging Spectrograph (UVIS) confirmed this result by observing two stellar occultations during the February 17 and July 14 encounters. Unlike the magnetometer, UVIS failed to detect an atmosphere above Enceladus during the February encounter when it looked for evidence for an atmosphere over the equatorial region, but did detect water vapor during an occultation over the south polar region during the July encounter.
Fortuitously, Cassini flew through this gas cloud during the July 14 encounter, allowing instruments like the ion and neutral mass spectrometer (INMS) and the cosmic dust analyzer (CDA) to directly sample the plume. INMS measured the composition of the gas cloud, detecting mostly water vapor, as well as minor components like molecular nitrogen, methane, and carbon dioxide. CDA "detected a large increase in the number of particles near Enceladus", confirming Enceladus as the primary source for the E ring. Analysis of the CDA and INMS data suggest that the gas cloud Cassini flew through during the July encounter, and observed from a distance with its magnetometer and UVIS, was actually a water-rich cryovolcanic plume, originating from vents near the south pole.
Visual confirmation of venting came in November 2005, when ISS (Imaging Science Subsystem) imaged geyser-like jets of icy particles rising from the moon's south polar region.(As stated above, the plume was imaged before, in January and February 2005, but additional studies of the camera's response at high phase angles, when the Sun is almost behind Enceladus, and comparison with equivalent high-phase-angle images taken of other Saturnian satellites, were required before this could be confirmed.The images taken in November 2005 showed the plume's fine structure, revealing numerous jets (perhaps issuing from numerous distinct vents) within a larger, faint component extending out nearly 500 km from the surface, thus making Enceladus the fourth body in the Solar System to have confirmed volcanic activity, along with Earth, Neptune's Triton, and Jupiter's Io.Cassini's UVIS later observed gas jets coinciding with the dust jets seen by ISS during a non-targeted encounter with Enceladus in October 2007.
Additional observations were acquired during a flyby on March 12, 2008. Data on this flyby revealed additional chemicals in the plume, including simple and complex hydrocarbons such as propane, ethane, and acetylene.This finding further raises the potential for life beneath the surface of Enceladus.The composition of Enceladus's plume as measured by the INMS instrument on Cassini is similar to that seen at most comets.
The intensity of the eruption of the south polar jets varies significantly as a function of the position of Enceladus in its orbit. The plumes are about four times brighter when Enceladus is at apoapsis (the point in its orbit most distant from Saturn) than when it is at periapsis. Geophysical modeling of tidal stresses indicates that at apoapsis the Tiger Stripes region is in a state of maximum tension, which would tend to open the fissures, while compression is maximal at periapsis.

Ammonia discovery
In July 2009 it was announced that ammonia had been discovered during flybys in July and October 2008. This acts like anti-freeze this will allow the water under the surface freezing temp to be increased
Internal structure

Prior to the Cassini mission, relatively little was known about the interior of Enceladus. However, results from recent flybys of Enceladus by the Cassini spacecraft have provided much needed information for models of Enceladus's interior. These include a better determination of the mass and tri-axial ellipsoid shape, high-resolution observations of the surface, and new insights on Enceladus's geochemistry.
Mass estimates from the Voyager program missions suggested that Enceladus was composed almost entirely of water ice.However, based on the effects of Enceladus's gravity on Cassini, its mass was determined to be much higher than previously thought, yielding a density of 1.61 g/cm³. This density is higher than Saturn's other mid-sized icy satellites, indicating that Enceladus contains a greater percentage of silicates and iron. With additional material besides water ice, Enceladus's interior may have experienced comparatively more heating from the decay of radioactive elements.
Castillo et al. 2005 suggested that Iapetus, and the other icy satellites of Saturn, formed relatively quickly after the formation of the Saturnian subnebula, and thus were rich in short-lived radionuclides. These radionuclides, like aluminium-26 and iron-60, have short half-lives and would produce interior heating relatively quickly. Without the short-lived variety, Enceladus's complement of long-lived radionuclides would not have been enough to prevent rapid freezing of the interior, even with Enceladus's comparatively high rock–mass fraction, given Enceladus's small size. Given Enceladus's relatively high rock–mass fraction, the proposed enhancement in 26Al and 60Fe would result in a differentiated body, with an icy mantle and a rocky core. Subsequent radioactive and tidal heating would raise the temperature of the core to 1000 K, enough to melt the inner mantle. However, for Enceladus to still be active, part of the core must have melted too, forming magma chambers that would flex under the strain of Saturn's tides. Tidal heating, such as from the resonance with Dione or from libration, would then have sustained these hot spots in the core until the present, and would power the current geological activity.
In addition to its mass and modeled geochemistry, researchers have also examined Enceladus's shape to test whether it is differentiated or not. Porco et al. 2006 used limb measurements to determine that Enceladus's shape, assuming it is in hydrostatic equilibrium, is consistent with an undifferentiated interior, in contradiction to the geological and geochemical evidence.However, the current shape also supports the possibility that Enceladus is not in hydrostatic equilibrium, and may have rotated faster at some point in the recent past (with a differentiated interior).

Possible water ocean
In late 2008, scientists observed water vapor spewing from Enceladus's surface, and it was later discovered that this vapor trails into Saturn. This could indicate the presence of liquid water, which might also make it possible for Enceladus to support life. Candice Hansen, a scientist with NASA's Jet Propulsion Lab, headed up a research team on the plumes after they were found to be moving at1,360 miles per hour). Since that speed is difficult to attain unless liquids are involved, they decided to investigate the compositions of the plumes.
Eventually it was discovered that in the E-ring about 6% of particles contain 0.5–2% of sodium salts by mass, which is a significant amount. In the parts of the plume close to Enceladus the fraction of "salty" particles increases to 70% by number and >99% by mass. Such particles presumably are frozen spray from the salty underground ocean. On the other hand, the small salt-poor particles form by homogenous nucleation directly from the gas phase. The sources of salty particles are uniformly distributed along the tiger stripes, whereas sources of "fresh" particles are closely related to the high-speed gas jets. The "salty" particles move slowly and mostly fall back onto the surface, while the fast "fresh" particles escape to the E-ring, explaining its salt-poor composition.
The "salty" composition of the plume strongly suggests that its source is a subsurface salty ocean or subsurface caverns filled with salty water. Alternatives such as the clathrate sublimation hypothesis can not explain how "salty" particles form.Additionally, Cassini found traces of organic compounds in some dust grains. Enceladus is therefore a candidate for harboring extraterrestrial life.
The presence of liquid water under the crust implies that there is an internal heat source. It is now thought to be a combination of radioactive decay and tidal heating, as tidal heating alone is not sufficient to explain the heat.
I wish we could send a probe into every one of these moon with water under their surface, But we must be careful not to place life there from the Earth. This why when Cassini is done. Its orbit would be aim at Saturn this away it wouldn't land on this or Titan . The orbiter wasn't clean .well it wasn't clean to get rid of any thing a life on its surface. Before the probe if its going to be send into this moon sea,would be clean up extra careful. Did you know that a bug on a landed we send to the moon was still alive when they took the leg back to Earth( Surveyor 3)

Uranus

Uranus presented a featureless disk to Voyager 2 in 1986. Its appearance reflects the presence of a high-altitude hydrocarbon photochemical haze overlying clouds of methane, which in turn overlie clouds of hydrogen sulfide and/or ammonia (below these are additional unseen cloud decks of different compositions). The blue-green coloration results from the absorption bands of methane.
Uranus is the seventh planet from the Sun. It has the third-largest planetary radius and fourth-largest planetary mass in the Solar System. Uranus is similar in composition to Neptune, and both are of different chemical composition than the larger gas giants Jupiter and Saturn. For this reason, astronomers sometimes place them in a separate category called "ice giants". Uranus's atmosphere, although similar to Jupiter's and Saturn's in its primary composition of hydrogen and helium, contains more "ices" such as water, ammonia, and methane, along with traces of hydrocarbons. It is the coldest planetary atmosphere in the Solar System, with a minimum temperature of 49 K (−224.2 °C), and has a complex, layered cloud structure, with water thought to make up the lowest clouds, and methane the uppermost layer of clouds. In contrast, the interior of Uranus is mainly composed of ices and rock.
It is the only planet whose name is derived from a figure from Greek mythology rather than Roman mythology like the other planets, from the Latinized version of the Greek god of the sky, Ouranos. Like the other giant planets, Uranus has a ring system, a magnetosphere, and numerous moons. The Uranian system has a unique configuration among those of the planets because its axis of rotation is tilted sideways, nearly into the plane of its revolution about the Sun. Its north and south poles therefore lie where most other planets have their equators. In 1986, images from Voyager 2 showed Uranus as a virtually featureless planet in visible light without the cloud bands or storms associated with the other giants. Terrestrial observers have seen signs of seasonal change and increased weather activity in recent years as Uranus approached its equinox. The wind speeds on Uranus can reach 250 meters per second (900 km/h, 560 mph).
Discovery
Uranus had been observed on many occasions before its recognition as a planet, but it was generally mistaken for a star. The earliest recorded sighting was in 1690 when John Flamsteed observed it at least six times, cataloging it as 34 Tauri. The French astronomer Pierre Lemonnier observed Uranus at least twelve times between 1750 and 1769,including on four consecutive nights.
Sir William Herschel observed Uranus on March 13, 1781 while in the garden of his house at 19 New King Street in the town of Bath, Somerset, England (now the Herschel Museum of Astronomy), but initially reported it (on April 26, 1781) as a "comet". Herschel "engaged in a series of observations on the parallax of the fixed stars", using a telescope of his own design.
He recorded in his journal "In the quartile near ζ Tauri ... either [a] Nebulous star or perhaps a comet". On March 17, he noted, "I looked for the Comet or Nebulous Star and found that it is a Comet, for it has changed its place". When he presented his discovery to the Royal Society, he continued to assert that he had found a comet, but also implicitly compared it to a planet:
The power I had on when I first saw the comet was 227. From experience I know that the diameters of the fixed stars are not proportionally magnified with higher powers, as planets are; therefore I now put the powers at 460 and 932, and found that the diameter of the comet increased in proportion to the power, as it ought to be, on the supposition of its not being a fixed star, while the diameters of the stars to which I compared it were not increased in the same ratio. Moreover, the comet being magnified much beyond what its light would admit of, appeared hazy and ill-defined with these great powers, while the stars preserved that lustre and distinctness which from many thousand observations I knew they would retain. The sequel has shown that my surmises were well-founded, this proving to be the Comet we have lately observed.

The telescope used to discover Uranus,the 1st planet discover by telescope(Replica)
Herschel notified the Astronomer Royal, Nevil Maskelyne, of his discovery and received this flummoxed reply from him on April 23: "I don't know what to call it. It is as likely to be a regular planet moving in an orbit nearly circular to the sun as a Comet moving in a very eccentric ellipsis. I have not yet seen any coma or tail to it".
Although Herschel continued to cautiously describe his new object as a comet, other astronomers had already begun to suspect otherwise. Russian astronomer Anders Johan Lexell was the first to compute the orbit of the new object and its nearly circular orbit led him to a conclusion that it was a planet rather than a comet. Berlin astronomer Johann Elert Bode described Herschel's discovery as "a moving star that can be deemed a hitherto unknown planet-like object circulating beyond the orbit of Saturn". Bode concluded that its near-circular orbit was more like a planet than a comet.
The object was soon universally accepted as a new planet. By 1783, Herschel himself acknowledged this fact to Royal Society president Joseph Banks: "By the observation of the most eminent Astronomers in Europe it appears that the new star, which I had the honour of pointing out to them in March 1781, is a Primary Planet of our Solar System." In recognition of his achievement, King George III gave Herschel an annual stipend of £200 on the condition that he move to Windsor so that the Royal Family could have a chance to look through his telescopes.

William Herschel, discoverer of Uranus
Name
Uranus is named after the ancient Greek deity of the sky Uranus (Ancient Greek: Οὐρανός), the father of Cronus (Saturn) and grandfather of Zeus (Jupiter), which in Latin became "Ūranus". It is the only planet whose name is derived from a figure from Greek mythology rather than Roman mythology.
Orbit and rotation
Uranus revolves around the Sun once every 84 Earth years. Its average distance from the Sun is roughly 3 billion km (about 20 AU). The intensity of sunlight on Uranus is about 1/400 that on Earth. Its orbital elements were first calculated in 1783 by Pierre-Simon Laplace.With time, discrepancies began to appear between the predicted and observed orbits, and in 1841, John Couch Adams first proposed that the differences might be due to the gravitational tug of an unseen planet. In 1845, Urbain Le Verrier began his own independent research into Uranus's orbit. On September 23, 1846, Johann Gottfried Galle located a new planet, later named Neptune, at nearly the position predicted by Le Verrier.
The rotational period of the interior of Uranus is 17 hours, 14 minutes, clockwise (retrograde). As on all giant planets, its upper atmosphere experiences very strong winds in the direction of rotation. At some latitudes, such as about two-thirds of the way from the equator to the south pole, visible features of the atmosphere move much faster, making a full rotation in as little as 14 hours.

Axial tilt
Uranus has an axial tilt of 97.77°, so its axis of rotation is approximately parallel with the plane of the Solar System. This gives it seasonal changes completely unlike those of the other major planets. Other planets can be visualized to rotate like tilted spinning tops on the plane of the Solar System, whereas Uranus rotates more like a tilted rolling ball. Near the time of Uranian solstices, one pole faces the Sun continuously whereas the other one faces away. Only a narrow strip around the equator experiences a rapid day–night cycle, but with the Sun very low over the horizon as in the Earth's polar regions. At the other side of Uranus's orbit the orientation of the poles towards the Sun is reversed. Each pole gets around 42 years of continuous sunlight, followed by 42 years of darkness. Near the time of the equinoxes, the Sun faces the equator of Uranus giving a period of day–night cycles similar to those seen on most of the other planets. Uranus reached its most recent equinox on December 7, 2007.
One result of this axis orientation is that, on average during the year, the polar regions of Uranus receive a greater energy input from the Sun than its equatorial regions. Nevertheless, Uranus is hotter at its equator than at its poles. The underlying mechanism that causes this is unknown. The reason for Uranus's unusual axial tilt is also not known with certainty, but the usual speculation is that during the formation of the Solar System, an Earth-sized protoplanet collided with Uranus, causing the skewed orientation. Uranus's south pole was pointed almost directly at the Sun at the time of Voyager 2's flyby in 1986. The labeling of this pole as "south" uses the definition currently endorsed by the International Astronomical Union, namely that the north pole of a planet or satellite shall be the pole that points above the invariable plane of the Solar System, regardless of the direction the planet is spinning. A different convention is sometimes used, in which a body's north and south poles are defined according to the right-hand rule in relation to the direction of rotation.In terms of this latter coordinate system it was Uranus's north pole that was in sunlight in 1986.
Visibility
From 1995 to 2006, Uranus's apparent magnitude fluctuated between +5.6 and +5.9, placing it just within the limit of naked eye visibility at +6.5. Its angular diameter is between 3.4 and 3.7 arcseconds, compared with 16 to 20 arcseconds for Saturn and 32 to 45 arcseconds for Jupiter. At opposition, Uranus is visible to the naked eye in dark skies, and becomes an easy target even in urban conditions with binoculars. In larger amateur telescopes with an objective diameter of between 15 and 23 cm, Uranus appears as a pale cyan disk with distinct limb darkening. With a large telescope of 25 cm or wider, cloud patterns, as well as some of the larger satellites, such as Titania and Oberon, may be visible.

A 1998 false-colour near-infrared image of Uranus showing cloud bands, rings, and moons obtained by the Hubble Space Telescope's NICMOS camera.
 
Uranus's mass is roughly 14.5 times that of the Earth, making it the least massive of the giant planets. Its diameter is slightly larger than Neptune's at roughly four times Earth's. A resulting density of 1.27 g/cm3 makes Uranus the second least dense planet, after Saturn. This value indicates that it is made primarily of various ices, such as water, ammonia, and methane. The total mass of ice in Uranus's interior is not precisely known, because different figures emerge depending on the model chosen; it must be between 9.3 and 13.5 Earth masses.Hydrogen and helium constitute only a small part of the total, with between 0.5 and 1.5 Earth masses.The remainder of the non-ice mass (0.5 to 3.7 Earth masses) is accounted for by rocky material.
The standard model of Uranus's structure is that it consists of three layers: a rocky (silicate/iron-nickel) core in the center, an icy mantle in the middle and an outer gaseous hydrogen/helium envelope. The core is relatively small, with a mass of only 0.55 Earth masses and a radius less than 20% of Uranus's; the mantle comprises its bulk, with around 13.4 Earth masses, whereas the upper atmosphere is relatively insubstantial, weighing about 0.5 Earth masses and extending for the last 20% of Uranus's radius. Uranus's core density is around 9 g/cm3, with a pressure in the center of 8 million bars (800 GPa) and a temperature of about 5000 K. The ice mantle is not in fact composed of ice in the conventional sense, but of a hot and dense fluid consisting of water, ammonia and other volatiles. This fluid, which has a high electrical conductivity, is sometimes called a water–ammonia ocean. Research conducted at the University of California, Berkeley and by Isaac Silvera of Harvard University suggests that methane found in the deepest regions of Uranus's atmosphere and within the mantle may in fact condense into an ocean of liquid diamond due to the extreme heat and pressure found at depth. Women come and get the diamonds
The bulk compositions of Uranus and Neptune are very different from those of Jupiter and Saturn, with ice dominating over gases, hence justifying their separate classification as ice giants. There may be a layer of ionic water where the water molecules break down into a soup of hydrogen and oxygen ions, and deeper down superionic water in which the oxygen crystallises but the hydrogen ions move freely within the oxygen lattice.
Although the model considered above is reasonably standard, it is not unique; other models also satisfy observations. For instance, if substantial amounts of hydrogen and rocky material are mixed in the ice mantle, the total mass of ices in the interior will be lower, and, correspondingly, the total mass of rocks and hydrogen will be higher. Presently available data does not allow science to determine which model is correct.The fluid interior structure of Uranus means that it has no solid surface. The gaseous atmosphere gradually transitions into the internal liquid layers.[For the sake of convenience, a revolving oblate spheroid set at the point at which atmospheric pressure equals 1 bar (100 kPa) is conditionally designated as a "surface". It has equatorial and polar radii of 25 559 ± 4 and 24 973 ± 20 km, respectively.This surface will be used throughout this article as a zero point for altitudes.
Internal heat
Uranus's internal heat appears markedly lower than that of the other giant planets; in astronomical terms, it has a low thermal flux. Why Uranus's internal temperature is so low is still not understood. Neptune, which is Uranus's near twin in size and composition, radiates 2.61 times as much energy into space as it receives from the Sun. Uranus, by contrast, radiates hardly any excess heat at all. The total power radiated by Uranus in the far infrared (i.e. heat) part of the spectrum is 1.06 ± 0.08 times the solar energy absorbed in its atmosphere. In fact, Uranus's heat flux is only 0.042 ± 0.047 W/m2, which is lower than the internal heat flux of Earth of about 0.075 W/m2. The lowest temperature recorded in Uranus's tropopause is 49 K (−224 °C), making Uranus the coldest planet in the Solar System.
One of the hypotheses for this discrepancy suggests that when Uranus was hit by a supermassive impactor, which caused it to expel most of its primordial heat, it was left with a depleted core temperature. Another hypothesis is that some form of barrier exists in Uranus's upper layers that prevents the core's heat from reaching the surface. For example, convection may take place in a set of compositionally different layers, which may inhibit the upward heat transport;it is possible that double diffusive convection is a limiting factor.

Atmosphere
Although there is no well-defined solid surface within Uranus's interior; the outermost part of Uranus's gaseous envelope that is accessible to remote sensing is called its atmosphere. Remote-sensing capability extends down to roughly 300 km below the 1 bar (100 kPa) level, with a corresponding pressure around 100 bar (10 MPa) and temperature of 320 K. The tenuous corona of the atmosphere extends remarkably over two planetary radii from the nominal surface, which is defined to lie at a pressure of 1 bar. The Uranian atmosphere can be divided into three layers: the troposphere, between altitudes of −300 and 50 km and pressures from 100 to 0.1 bar; (10 MPa to 10 kPa), the stratosphere, spanning altitudes between 50 and 4000 km and pressures of between 0.1 and 10−10 bar (10 kPa to 10 µPa), and the thermosphere/corona extending from 4,000 km to as high as 50,000 km from the surface. There is no mesosphere.
Composition
The composition of the Uranian atmosphere is different from its bulk, consisting mainly of molecular hydrogen and helium. The helium molar fraction, i.e. the number of helium atoms per molecule of gas, is 0.15 ± 0.03[15] in the upper troposphere, which corresponds to a mass fraction 0.26 ± 0.05.This value is very close to the protosolar helium mass fraction of 0.275 ± 0.01, indicating that helium has not settled in its center like it has in the gas giants.The third most abundant constituent of the Uranian atmosphere is methane (CH4). Methane possesses prominent absorption bands in the visible and near-infrared (IR) making Uranus aquamarine or cyan in color.Methane molecules account for 2.3% of the atmosphere by molar fraction below the methane cloud deck at the pressure level of 1.3 bar (130 kPa); this represents about 20 to 30 times the carbon abundance found in the Sun. The mixing ratio[h] is much lower in the upper atmosphere owing to its extremely low temperature, which lowers the saturation level and causes excess methane to freeze out.The abundances of less volatile compounds such as ammonia, water and hydrogen sulfide in the deep atmosphere are poorly known. They are probably also higher than solar values. Along with methane, trace amounts of various hydrocarbons are found in the stratosphere of Uranus, which are thought to be produced from methane by photolysis induced by the solar ultraviolet (UV) radiation. They include ethane (C2H6), acetylene (C2H2), methylacetylene (CH3C2H), and diacetylene (C2HC2H).Spectroscopy has also uncovered traces of water vapor, carbon monoxide and carbon dioxide in the upper atmosphere, which can only originate from an external source such as infalling dust and comets.
Troposphere
The troposphere is the lowest and densest part of the atmosphere and is characterized by a decrease in temperature with altitude. The temperature falls from about 320 K at the base of the nominal troposphere at −300 km to 53 K at 50 km.The temperatures in the coldest upper region of the troposphere (the tropopause) actually vary in the range between 49 and 57 K depending on planetary latitude.The tropopause region is responsible for the vast majority of Uranus's thermal far infrared emissions, thus determining its effective temperature of 59.1 ± 0.3 K.
The troposphere is believed to possess a highly complex cloud structure; water clouds are hypothesised to lie in the pressure range of 50 to 100 bar (5 to 10 MPa), ammonium hydrosulfide clouds in the range of 20 to 40 bar (2 to 4 MPa), ammonia or hydrogen sulfide clouds at between 3 and 10 bar (0.3 to 1 MPa) and finally directly detected thin methane clouds at 1 to 2 bar (0.1 to 0.2 MPa). The troposphere is a very dynamic part of the atmosphere, exhibiting strong winds, bright clouds and seasonal changes.
Planetary rings
All of the planet of the outer solar system have ring. Jupiter,Saturn,Uranus,Neptune!
Saturn ring can be view by a small telescope while other was discovery by space probes or other means,Some of the ring are made out difference matter

The rings are composed of extremely dark particles, which vary in size from micrometers to a fraction of a meter.Thirteen distinct rings are presently known, the brightest being the ε ring. All except two rings of Uranus are extremely narrow – they are usually a few kilometres wide. The rings are probably quite young; the dynamics considerations indicate that they did not form with Uranus. The matter in the rings may once have been part of a moon (or moons) that was shattered by high-speed impacts. From numerous pieces of debris that formed as a result of those impacts only a few particles survived in a limited number of stable zones corresponding to present rings.
William Herschel described a possible ring around Uranus in 1789. This sighting is generally considered doubtful, because the rings are quite faint, and in the two following centuries none were noted by other observers. Still, Herschel made an accurate description of the epsilon ring's size, its angle relative to the Earth, its red color, and its apparent changes as Uranus traveled around the Sun. The ring system was definitively discovered on March 10, 1977 by James L. Elliot, Edward W. Dunham, and Douglas J. Mink using the Kuiper Airborne Observatory. The discovery was serendipitous; they planned to use the occultation of the star SAO 158687 by Uranus to study its atmosphere. When their observations were analyzed, they found that the star had disappeared briefly from view five times both before and after it disappeared behind Uranus. They concluded that there must be a ring system around Uranus. Later they detected four additional rings. The rings were directly imaged when Voyager 2 passed Uranus in 1986. Voyager 2 also discovered two additional faint rings bringing the total number to eleven.

In December 2005, the Hubble Space Telescope detected a pair of previously unknown rings. The largest is located at twice the distance from Uranus of the previously known rings. These new rings are so far from Uranus that they are called the "outer" ring system. Hubble also spotted two small satellites, one of which, Mab, shares its orbit with the outermost newly discovered ring. The new rings bring the total number of Uranian rings to 13. In April 2006, images of the new rings with the Keck Observatory yielded the colours of the outer rings: the outermost is blue and the other red. One hypothesis concerning the outer ring's blue color is that it is composed of minute particles of water ice from the surface of Mab that are small enough to scatter blue light. In contrast, Uranus's inner rings appear grey.
Magnetosphere(like of the larger planet they are very powerful but the only way to measure them is to send a space probe
Before the arrival of Voyager 2, no measurements of the Uranian magnetosphere had been taken, so its nature remained a mystery. Before 1986, astronomers had expected the magnetic field of Uranus to be in line with the solar wind, because it would then align with Uranus's poles that lie in the ecliptic.
Voyager's observations revealed that Uranus's magnetic field is peculiar, both because it does not originate from its geometric center, and because it is tilted at 59° from the axis of rotation.In fact the magnetic dipole is shifted from the Uranus's center towards the south rotational pole by as much as one third of the planetary radius. This unusual geometry results in a highly asymmetric magnetosphere, where the magnetic field strength on the surface in the southern hemisphere can be as low as 0.1 gauss (10 µT), whereas in the northern hemisphere it can be as high as 1.1 gauss (110 µT). The average field at the surface is 0.23 gauss (23 µT). In comparison, the magnetic field of Earth is roughly as strong at either pole, and its "magnetic equator" is roughly parallel with its geographical equator. The dipole moment of Uranus is 50 times that of Earth. Neptune has a similarly displaced and tilted magnetic field, suggesting that this may be a common feature of ice giants. One hypothesis is that, unlike the magnetic fields of the terrestrial and gas giants, which are generated within their cores, the ice giants' magnetic fields are generated by motion at relatively shallow depths, for instance, in the water–ammonia ocean. Another possible explanation for the magnetosphere's alignment is that there are oceans of liquid diamond in Uranus's interior that would deter the magnetic field.
Despite its curious alignment, in other respects the Uranian magnetosphere is like those of other planets: it has a bow shock located at about 23 Uranian radii ahead of it, a magnetopause at 18 Uranian radii, a fully developed magnetotail and radiation belts. Overall, the structure of Uranus's magnetosphere is different from Jupiter's and more similar to Saturn's. Uranus's magnetotail trails behind it into space for millions of kilometers and is twisted by its sideways rotation into a long corkscrew.
Uranus's magnetosphere contains charged particles: protons and electrons with small amount of H2+ ions. No heavier ions have been detected. Many of these particles probably derive from the hot atmospheric corona.The ion and electron energies can be as high as 4 and 1.2 megaelectronvolts, respectively.The density of low-energy (below 1 kiloelectronvolt) ions in the inner magnetosphere is about 2 cm−3. The particle population is strongly affected by the Uranian moons that sweep through the magnetosphere leaving noticeable gaps. The particle flux is high enough to cause darkening or space weathering of their surfaces on an astronomically rapid timescale of 100,000 years. This may be the cause of the uniformly dark colouration of the Uranian satellites and rings. Uranus has relatively well developed aurorae, which are seen as bright arcs around both magnetic poles.Unlike Jupiter's, Uranus's aurorae seem to be insignificant for the energy balance of the planetary thermosphere.

Some thing can be seen but it kind of boring to look at while other planet show very violent storm on it socalled surface. There had been afew dark spot .They been using the telescope Hubble Space Telescope (HST) and Keck to watch Uranus as it weather shift remember the planet is just rounding on its side...
No other space probe is funded to go back ,there has be called to go back but with travel time to send orbiter about 12 years but they need to start now,,,

Horsehead and Orion Nebulas

Horsehead and Orion Nebulas
The dark Horsehead Nebula and the glowing Orion Nebula are contrasting cosmic vistas. Adrift 1,500 light-years away in one of the night sky's most recognizable constellations, they appear in opposite corners of the above stunning mosaic. The familiar Horsehead nebula appears as a dark cloud, a small silhouette notched against the long red glow at the lower left. Alnitak is the easternmost star in Orion's belt and is seen as the brightest star to the left of the Horsehead. Below Alnitak is the Flame Nebula, with clouds of bright emission and dramatic dark dust lanes. The magnificent emission region, the Orion Nebula (aka M42), lies at the upper right. Immediately to its left is a prominent reflection nebula sometimes called the Running Man. Pervasive tendrils of glowing hydrogen gas are easily traced throughout the region.