Friday, February 24, 2012

The Rosette Nebula

The Rosette Nebula is not the only cosmic cloud of gas and dust to evoke the imagery of flowers -- but it is the most famous. At the edge of a large molecular cloud in Monoceros, some 5,000 light years away, the petals of this rose are actually a stellar nursery whose lovely, symmetric shape is sculpted by the winds and radiation from its central cluster of hot young stars. The stars in the energetic cluster, cataloged as NGC 2244, are only a few million years old, while the central cavity in the Rosette Nebula, cataloged as NGC 2237, is about 50 light-years in diameter. The nebula can be seen firsthand with a small telescope toward the constellation of the Unicorn (Monoceros).

Orion in Gas, Dust, and Stars

The constellation of Orion holds much more than three stars in a row. A deep exposure shows everything from dark nebula to star clusters, all embedded in an extended patch of gaseous wisps in the greater Orion Molecular Cloud Complex. The brightest three stars on the far left are indeed the famous three stars that make up the belt of Orion. Just below Alnitak, the lowest of the three belt stars, is the Flame Nebula, glowing with excited hydrogen gas and immersed in filaments of dark brown dust. Below the frame center and just to the right of Alnitak lies the Horsehead Nebula, a dark indentation of dense dust that has perhaps the most recognized nebular shapes on the sky. On the upper right lies M42, the Orion Nebula, an energetic caldron of tumultuous gas, visible to the unaided eye, that is giving birth to a new open cluster of stars. Immediately to the left of M42 is a prominent bluish reflection nebula sometimes called the Running Man that houses many bright blue stars. The above image, a digitally stitched composite taken over several nights, covers an area with objects that are roughly 1,500 light years away and spans about 75 light years.


Rich in star clusters and nebulae, the ancient constellation of Auriga, the Charioteer, rides high in northern winter night skies. Composed from narrow and broadband filter data and spanning nearly 8 Full Moons (4 degrees) on the sky, this deep telescopic view recorded in January shows off some of Auriga's celestial bounty. The field includes emission region IC 405 (top left) about 1,500 light-years distant. Also known as the Flaming Star Nebula, its red, convoluted clouds of glowing hydrogen gas are energized by hot O-type star AE Aurigae. IC 410 (top right) is significantly more distant, some 12,000 light-years away. The star forming region is famous for its embedded young star cluster, NGC 1893, and tadpole-shaped clouds of dust and gas. IC 417 and NGC 1931 at the lower right, the Spider and the Fly, are also young star clusters embedded in natal clouds that lie far beyond IC 405. Star cluster NGC 1907 is near the bottom edge of the frame, just right of center. The crowded field of view looks along the plane of our Milky Way galaxy, near the direction of the galactic anticenter.
Many spiral galaxies have bars across their centers. Even our own Milky Way Galaxy is thought to have a modest central bar. Prominently barred spiral galaxy NGC 1073, pictured above, was captured in spectacular detail in this recently released image taken by the orbiting Hubble Space Telescope. Visible are dark filamentary dust lanes, young clusters of bright blue stars, red emission nebulas of glowing hydrogen gas, a long bright bar of stars across the center, and a bright active nucleus that likely houses a supermassive black hole. Light takes about 55 million years to reach us from NGC 1073, which spans about 80,000 light years across. NGC 1073 can be seen with a moderately-sized telescope toward the constellation of the Sea Monster (Cetus), Fortuitously, the above image not only caught the X-ray bright star system IXO 5, visible on the upper left and likely internal to the barred spiral, but three quasars far in the distance.

Monday, February 13, 2012

The space probe that is orbiting around Saturn

Cassini–Huygens is a joint NASA/ESA/ASI spacecraft mission studying the planet Saturn and its many natural satellites since 2004. Launched in 1997 after nearly two decades of gestation, it includes a Saturn orbiter and an atmospheric probe/lander for the moon Titan, although it has also returned data on a wide variety of other things including the Heliosphere, Jupiter, and relativity tests. The Titan probe, Huygens, entered and landed on Titan in 2005. The current end of mission plan is a 2017 Saturn impact.
The complete Cassini–Huygens space probe was launched on October 15, 1997 by a Titan IVB/Centaur, and after a long interplanetary voyage it entered into orbit around Saturn on July 1, 2004. On December 25, 2004, the Huygens probe was separated from the orbiter at approximately 02:00 UTC. It reached Saturn's moon Titan on January 14, 2005, when it descended into Titan's atmosphere, and downward to the surface, radioing scientific information back to the Earth by telemetry. This was the first landing ever accomplished in the outer Solar System. On April 18, 2008, NASA announced a two-year extension of the funding for ground operations of this mission, at which point it was renamed to Cassini Equinox Mission.This was again extended in February 2010 with the Cassini Solstice Mission continuing until 2017. Cassini is the fourth space probe to visit Saturn and the first to enter orbit.
Sixteen European countries and the United States make up the team responsible for designing, building, flying and collecting data from the Cassini orbiter and Huygens probe. The mission is managed by NASA’s Jet Propulsion Laboratory in the United States, where the orbiter was designed and assembled. Development of the Huygens Titan probe was managed by the European Space Research and Technology Centre, whose prime contractor for the probe was the Alcatel company in France. Equipment and instruments for the probe were supplied from many countries. The Italian Space Agency (ASI) provided the Cassini probe's high-gain radio antenna, and a compact and lightweight radar, which acts in multipurpose as a synthetic aperture radar, a radar altimeter, and a radiometer.
Cassini is powered by 72 pounds (32.7 kg )of Plutonium-238 — the heat from the material's radioactive decay is turned into electricity. Huygens was supported by Cassini during cruise, but used chemical batteries when independent.
The spacecraft consists of two main elements: the ASI/NASA Cassini orbiter, named for the Italian-French astronomer Giovanni Domenico Cassini, (also known later as Jean-Dominique Cassini when he became a citizen of France), and the ESA-developed Huygens probe, named for the Dutch astronomer, mathematician and physicist Christiaan Huygens. It was commonly called Saturn Orbiter Titan Probe (SOTP) during gestation, both as a Mariner Mark II mission and generically. Huygens discovered Titan, and Cassini discovered a few more of Saturn's moons.
The spacecraft was originally planned to be the second three-axis stabilized, RTG-powered Mariner Mark II, a class of spacecraft developed for missions beyond the orbit of Mars.
Cassini was developed simultaneously with the Comet Rendezvous Asteroid Flyby (CRAF) spacecraft, but various budget cuts and rescopings of the project forced NASA to terminate CRAF development in order to save Cassini. As a result, the Cassini spacecraft became a more specialized design, canceling the implementation of the Mariner Mark II series.
The spacecraft, including the orbiter and the probe, is the largest and most complex interplanetary spacecraft built to date. The orbiter has a mass of 2,150 kg (4,700 lb), the probe 350 kg (770 lb). With the launch vehicle adapter and 3,132 kg (6,900 lb) of propellants at launch, the spacecraft had a mass of about 5,600 kg (12,000 lb). Only the two Phobos spacecraft sent to Mars by the Soviet Union were heavier.
The Cassini spacecraft is more than 6.8 meters (22 ft) high and more than 4 meters (13 ft) wide. The complexity of the spacecraft is necessitated both by its trajectory (flight path) to Saturn, and by the ambitious program of scientific observations once the spacecraft reaches its destination. Cassini has at least 1,630 interconnected electronic components, 22,000 wire connections, and over 14 kilometers (8.7 mi) of cabling. The core control computer CPU was a redundant MIL-STD-1750A control system.
Now that the Cassini probe is orbiting Saturn, it is between 8.2 and 10.2 astronomical units from the Earth. Because of this, it takes between 68 to 84 minutes for radio signals to travel from Earth to the spacecraft, and vice-versa. Thus, ground controllers cannot give "real-time" instructions to the spacecraft, either for day-to-day operations, or in cases of unexpected events. Even if they responded immediately after becoming aware of a problem, nearly three hours will have passed between the occurrence of the problem itself and the reception of the engineers' response by the satellite
Cassini's instrumentation consists of: a synthetic aperture radar mapper, a charge-coupled device imaging system, a visible/infrared mapping spectrometer, a composite infrared spectrometer, a cosmic dust analyzer, a radio and plasma wave experiment, a plasma spectrometer, an ultraviolet imaging spectrograph, a magnetospheric imaging instrument, a magnetometer and an ion/neutral mass spectrometer. Telemetry from the communications antenna and other special transmitters (an S-band transmitter and a dual-frequency Ka-band system) will also be used to make observations of the atmospheres of Titan and Saturn and to measure the gravity fields of the planet and its satellites.
Cassini Plasma Spectrometer (CAPS)

The CAPS is a direct sensing instrument that measures the energy and electrical charge of particles that the instrument encounters, (the number of electrons and protons in the particle). CAPS will measure the molecules originating from Saturn's ionosphere and also determine the configuration of Saturn's magnetic field. CAPS will also investigate plasma in these areas as well as the solar wind within Saturn's magnetosphere

Cosmic Dust Analyzer (CDA)

The CDA is a direct sensing instrument that measures the size, speed, and direction of tiny dust grains near Saturn. Some of these particles are orbiting Saturn, while others may come from other star systems. The CDA on the orbiter is designed to learn more about these mysterious particles, the materials in other celestial bodies and potentially about the origins of the universe.

Composite Infrared Spectrometer (CIRS)

The CIRS is a remote sensing instrument that measures the infrared waves coming from objects to learn about their temperatures, thermal properties, and compositions. Throughout the Cassini–Huygens mission, the CIRS will measure infrared emissions from atmospheres, rings and surfaces in the vast Saturn system. It will map the atmosphere of Saturn in three dimensions to determine temperature and pressure profiles with altitude, gas composition, and the distribution of aerosols and clouds. It will also measure thermal characteristics and the composition of satellite surfaces and rings

Ion and Neutral Mass Spectrometer (INMS)

The INMS is a direct sensing instrument that analyzes charged particles (like protons and heavier ions) and neutral particles (like atoms) near Titan and Saturn to learn more about their atmospheres. INMS is intended also to measure the positive ion and neutral environments of Saturn's icy satellites and rings

Imaging Science Subsystem (ISS)

The ISS is a remote sensing instrument that captures most images in visible light, and also some infrared images and ultraviolet images. The ISS has taken hundreds of thousands of images of Saturn, its rings, and its moons, for return to the Earth by radio telemetry. The ISS has a wide-angle camera (WAC) that takes pictures of large areas, and a narrow-angle camera (NAC) that takes pictures of small areas in fine detail. Each of these cameras uses a sensitive charge-coupled device (CCD) as its electromagnetic wave detector. Each CCD has a 1,024 square array of pixels, 12 μm on a side. Both cameras allow for many data collection modes, including on-chip data compression. Both cameras are fitted with spectral filters that rotate on a wheel—to view different bands within the electromagnetic spectrum ranging from 0.2 to 1.1 μm.

Dual Technique Magnetometer (MAG)

The MAG is a direct sensing instrument that measures the strength and direction of the magnetic field around Saturn. The magnetic fields are generated partly by the intensely hot molten core at Saturn's center. Measuring the magnetic field is one of the ways to probe the core, even though it is far too hot and deep to visit. MAG aims to develop a three-dimensional model of Saturn's magnetosphere, and determine the magnetic state of Titan and its atmosphere, and the icy satellites and their role in the magnetosphere of Saturn


The onboard radar is a remote active and remote passive sensing instrument that will produce maps of Titan's surface. It measures the height of surface objects (like mountains and canyons) by sending radio signals that bounce off Titan's surface and timing their return. Radio waves can penetrate the thick veil of haze surrounding Titan. The radar will listen for radio waves that Saturn or its moons may be producing

Radio and Plasma Wave Science instrument (RPWS)

The RPWS is a direct and remote sensing instrument that receives and measures radio signals coming from Saturn, including the radio waves given off by the interaction of the solar wind with Saturn and Titan. RPWS is to measure the electric and magnetic wave fields in the interplanetary medium and planetary magnetospheres. It will also determine the electron density and temperature near Titan and in some regions of Saturn's magnetosphere. RPWS studies the configuration of Saturn's magnetic field and its relationship to Saturn Kilometric Radiation (SKR), as well as monitoring and mapping Saturn's ionosphere, plasma, and lightning from Saturn's (and possibly Titan's) atmosphere

Radio Science Subsystem (RSS)

The RSS is a remote sensing instrument that uses radio antennas on Earth to observe the way radio signals from the spacecraft change as they are sent through objects, such as Titan's atmosphere or Saturn's rings, or even behind the Sun. The RSS also studies the compositions, pressures and temperatures of atmospheres and ionospheres, radial structure and particle size distribution within rings, body and system masses and gravitational waves. The instrument uses the spacecraft X-band communication link as well as S-band downlink and Ka-band uplink and downlink

Ultraviolet Imaging Spectrograph (UVIS)

The UVIS is a remote sensing instrument that captures images of the ultraviolet light reflected off an object, such as the clouds of Saturn and/or its rings, to learn more about their structure and composition. Designed to measure ultraviolet light over wavelengths from 55.8 to 190 nm, this instrument is also a valuable tool to help determine the composition, distribution, aerosol particle content and temperatures of their atmospheres. Unlike other types of spectrometer, this sensitive instrument can take both spectral and spatial readings. It is particularly adept at determining the composition of gases. Spatial observations take a wide-by-narrow view, only one pixel tall and 64 pixels across. The spectral dimension is 1,024 pixels per spatial pixel. Also, it can take many images that create movies of the ways in which this material is moved around by other forces

Visible and Infrared Mapping Spectrometer (VIMS)

The VIMS is a remote sensing instrument that captures images using visible and infrared light to learn more about the composition of moon surfaces, the rings, and the atmospheres of Saturn and Titan. It is made up of two cameras in one: one used to measure visible light, the other infrared. VIMS measures reflected and emitted radiation from atmospheres, rings and surfaces over wavelengths from 350 to 5100 nm, to help determine their compositions, temperatures and structures. It also observes the sunlight and starlight that passes through the rings to learn more about their structure. Scientists plan to use VIMS for long-term studies of cloud movement and morphology in the Saturn system, to determine Saturn's weather patterns
More info about the  Huygens probe later on!

Sunday, February 12, 2012

Enceladus Backlit by Saturn

This moon is shining by the light of its planet. Specifically, a large portion of Enceladus pictured above is illuminated primarily by sunlight first reflected from the planet Saturn. The result is that the normally snow-white moon appears in the gold color of Saturn's cloud tops. As most of the illumination comes from the image left, a labyrinth of ridges throws notable shadows just to the right of the image center, while the kilometer-deep canyon Labtayt Sulci is visible just below. The bright thin crescent on the far right is the only part of Enceladus directly lit by the Sun. The above image was taken last year by the robotic Cassini spacecraft during a close pass by by the enigmatic moon. Inspection of the lower part of this digitally sharpened image reveals plumes of ice crystals thought to originate in a below-surface sea.

At the Core of NGC 6752

Hubble Space Telescope view looks deep into NGC 6752. Some 13,000 light-years away toward the southern constellation Pavo, the globular star cluster roams the halo of our Milky Way galaxy. Over 10 billion years old, NGC 6752 holds over 100 thousand stars in a sphere about 100 light-years in diameter, but the Hubble image frame spans the central 10 or so light-years and resolves stars near the dense cluster core. In fact the frame includes some of the cluster's blue straggler stars, stars which appear to be too young and massive to exist in a cluster whose stars are all expected to be at least twice as old as the Sun. Explorations of the NGC 6752 have also indicated that a remarkable fraction of the stars near the cluster's core, are multiple star systems, supporting arguments that star mergers and collisions in the dense stellar environment can create the cluster's blue straggler stars.

Tuesday, February 7, 2012

Inside the Eagle Nebula

In 1995, a now famous picture from the Hubble Space Telescope featured Pillars of Creation, star forming columns of cold gas and dust light-years long inside M16, the Eagle Nebula. This remarkable false-color composite image revisits the nearby stellar nursery with image data from the orbiting Herschel Space Observatory and XMM-Newton telescopes. Herschel's far infrared detectors record the emission from the region's cold dust directly, including the famous pillars and other structures near the center of the scene. Toward the other extreme of the electromagnetic spectrum, XMM-Newton's X-ray vision reveals the massive, hot stars of the nebula's embedded star cluster. Hidden from Hubble's view at optical wavelengths, the massive stars have a profound effect, sculpting and transforming the natal gas and dust structures with their energetic winds and radiation. In fact, the massive stars are short lived and astronomers have found evidence in the image data pointing to the remnant of a supernova explosion with an apparent age of 6,000 years. If true, the expanding shock waves would have destroyed the visible structures, including the famous pillars. But because the Eagle Nebula is some 6,500 light-years distant, their destruction won't be witnessed for hundreds of years.

Dust of the Orion Nebula

What surrounds a hotbed of star formation? In the case of the Orion Nebula -- dust. The entire Orion field, located about 1600 light years away, is inundated with intricate and picturesque filaments of dust. Opaque to visible light, dust is created in the outer atmosphere of massive cool stars and expelled by a strong outer wind of particles. The Trapezium and other forming star clusters are embedded in the nebula. The intricate filaments of dust surrounding M42 and M43 appear brown in the above image, while central glowing gas is highlighted in red. Over the next few million years much of Orion's dust will be slowly destroyed by the very stars now being formed, or dispersed into the Galaxy.

Friday, February 3, 2012

99942 Apophis  previously known by its provisional designation 2004 MN) is a near-Earth asteroid that caused a brief period of concern in December 2004 because initial observations indicated a small probability (up to 2.7%) that it would strike the Earth in 2029. Additional observations provided improved predictions that eliminated the possibility of an impact on Earth or the Moon in 2029. However, a possibility remained that during the 2029 close encounter with Earth, Apophis would pass through a gravitational keyhole, a precise region in space no more than about a half-mile wide, that would set up a future impact on April 13, 2036. This possibility kept the asteroid at Level 1 on the Torino impact hazard scale until August 2006, when the probability that Apophis will pass through the keyhole was determined to be very small. Apophis broke the record for the highest level on the Torino Scale, being, for only a short time, a level 4, before it was lowered. Its diameter is approximately (885 ft).As of October 7, 2009 (2009 -10-07), the probability of an April 13, 2036 impact is considered to be 1 in 250,000. Of objects not recently observed, there are 7 asteroids with a more notable Palermo Technical Impact Hazard Scale than Apophis.
In 2008, The Planetary Society, a California-based space advocacy group, organized a $50,000 competition to design an unmanned space probe that would 'shadow' Apophis for almost a year, taking measurements that would "determine whether it will impact Earth, thus helping governments decide whether to mount a deflection mission to alter its orbit." The society received 37 entries from 20 countries on 6 continents.
The commercial competition was won by a design called 'Foresight' created by SpaceWorks Enterprises, Inc. SpaceWorks proposed a simple orbiter with only two instruments and a radio beacon at a cost of ~140 million USD, launched aboard a Minotaur IV between 2012 and 2014, to arrive at Apophis five to ten months later. It would then rendezvous with, observe, and track the asteroid. Foresight would orbit the asteroid to gather data with a multi-spectral imager for one month. It would then leave orbit and fly in formation with Apophis around the Sun at a range of two kilometers (1.2 miles). The spacecraft would use laser ranging to the asteroid and radio tracking from Earth for ten months to accurately determine the asteroid's orbit and how it might change.
Pharos, the winning student entry, would be an orbiter with four science instruments (a multi-spectral imager, near-infrared spectrometer, laser rangefinder, and magnetometer) that would rendezvous with and track Apophis. Earth-based tracking of the spacecraft would then allow precise tracking of the asteroid. The Pharos spacecraft would also carry four instrumented probes that it would launch individually over the course of two weeks. Accelerometers and temperature sensors on the probes would measure the seismic effects of successive probe impacts, a creative way to explore the interior structure and dynamics of the asteroid.
Second place, for $10,000, went to a European team led by Deimos Space S.L. of Madrid, Spain, in cooperation with EADS Astrium, Friedrichshafen, Germany; University of Stuttgart  Germany; and Università di Pisa, Italy. Juan L. Cano was Principal Investigator.
Another European team took home $5,000 for third place. Their team lead was EADS Astrium Ltd, United Kingdom, in conjunction with EADS Astrium SAS, France; IASF-Roma, INAF, Rome, Italy; Open University, UK; Rheinisches Institut für Umweltforschung, Germany; Royal Observatory of Belgium; and Telespazio, Italy. The Principal Investigator was Paolo D'Arrigo.
Two teams tied for second place in the Student Category: Monash University, Clayton Campus, Australia, with Dilani Kahawala as Principal Investigator; and University of Michigan, with Jeremy Hollander as Principal Investigator. Each second place team won $2,000. A team from Hong Kong Polytechnic University and Hong Kong University of Science and Technology under the leadership of Peter Weiss, received an honorable mention and $1,000 for the most innovative student proposal.
Apophis( his name in Greek)  is also a old God in Egyptian mythology!

Wednesday, February 1, 2012

A Winter time star map!

What happen in the Walking Dead show

obert Kirkman’s original comic book series “The Walking Dead” first aired on AMC on October 31st, 2010 to critical acclaim. The series follows protagonist Rick Grimes, who has awakened from a gunshot-induced coma to an apocalyptic reality. Unable to find medical support, he stumbles through and out of the hospital to find everything rotting and decaying away. He meet up with a man and his son, the latter originally hitting him over the head because he was thought to be a “walker.” After being debriefed on the chaos the world has fallen into, Rick departs for Atlanta in hopes of finding some amount of hope in the form of other people or a cure. After being ambushed in the city by a horde of zombies, he meets a group that is scouring the city for supplies to bring back to their home camp just outside the city limits. After a daring escape, Rick joins the group back outside the city and finds his wife and son among the refugees.  The story continually follows the trials and tribulations of the group as they try to deal with supplies, sanity, and each other. The zombies, thankfully Romero-style, antagonize the group at times when they need it most, often where they are at their most disconnected. Amid their struggles with one another, zombies attack the camp and kill nearly a third of all the members their, leading to some truly heart wrenching moments, as viewers are forced to watch a sister let her sibling reanimate from a zombie bite and kill her. Pressured, the group departs for the CDC, Center for Disease Control, in hopes of finding a cure or perhaps a glimmer of hope for the forlorn travelers. There they meet with a scientist, who reluctantly welcomes the group, who tells them that their chance at a cure has been eliminated and that all contact has been lost with the others across the world. Worse yet, the power is failing within the center and will self-destruct when the power is fully drained. Acknowledging this information, the group enjoys their temporary sojourn with food, friendship, and a little bit of alcohol that remind viewers that despite whatever tragedy can occur, we are and will always be human. However, the center eventually saps and a few members of the group remain to face a death far more peaceful than one they could receive from a zombie attack. After the main group leaves, one runs back to save another member, which is later revealed in the second season to be a regretful decision. The group leaves the CDC with the remaining members in hopes of finding a military facility that will hopefully offer conditions similar to the CDC without a self-destruct system. Season two picks up shortly afterwards, with the group running into a highway plagued with abandoned cars that bar their path. While looking for more supplies among the cars, the members are rushed by a horde of zombies that forces them to hide under cars. Members are injured in the process, and one little girl is discovered by the zombies and flees into the forest. She is chased by Rick, who eliminates the two zombies chasing her. Unfortunately, she is lost during the escape, and the rest of the season so far has been spent trying to find her. A search party is sent after the young girl, Sophia, and this leads their search to a church. She is not there, but Rick asks for a sign from God. The party splits again, and Rick finds a deer in the forest that he allows his son, Carl to approach. As he nears the deer, a shot rings out, piercing the deer and Carl by accident. In order to save his life, Carl is carried by his father to the hunter’s residence, where another group of survivors resides. Again, a part of the group finds temporary respite from the dangers of zombies, the ever-present danger. Shane, Rick’s partner throughout the entire series, is dispatched with the hunter to a local high school that will have the medical supplies necessary to save Carl’s life. Shane is forced to make a decision in this quest that will remind viewers of the disturbing steps one may take in order to get what they need. The characters must now prepare to hold their ground to hunt for Sophia, so that they may continue their quest towards the military base. However, the events at the high school where those medical supplies were held indicate that an even more harrowing journey lies ahead for the group.As you must had know by now that Sophia was bitten and was keep in the barn at the farm where they are staying. Shane lost his cool and break the lock off the barn and a whole group of the walkingdead came out and Shane and the other start shooting the dead.Sophia was the last one to came out and the whole group froze and it was up to Rick to take care of Sophia. Rick has to do what the other including Shane wouldn't do.To shoot the now walkingdead Sophia.The comic would have his son Carl to look at his dad in a difference way.
Make sure you guy watch this show.....