Gravity data collected by NASA’s Cassini spacecraft
suggest that Titan’s ocean must have an extremely high density. Salt
water has a higher density than fresh water because the presence of salt
adds more mass to a given amount of water.
Researchers think the ocean could be as salty as the Dead Sea of Israel
and Jordan, with a high concentration of dissolved salts made of
sulfur, sodium and potassium.
The average salt concentration in Earth’s oceans is around 3.5 percent,
but parts of the Dead Sea can reach 40 percent salinity.
Titan is surrounded by an ice shell, but below the surface, scientists believe there is an ocean of liquid water that could be just as salty as the Dead Sea.
Cassini collected gravity and topography data during its flybys of
Titan over the past 10 years, allowing researchers to create a new model
of the structure of the moon’s outer icy shell.
The new model suggests that the thickness of the icy crust varies
across the moon’s surface. This means that the ocean underneath is
probably in the process of freezing, too. If the ocean is freezing, it
would decrease the chances that the ocean could support life, since
freezing would limit the exchange of materials between the water and the
surface!!!
The new data could also provide some insight into Titan’s unique
atmosphere, which is consistently around 5 percent methane. It is still
a mystery how Titan maintains methane in its atmosphere since sunlight
quickly breaks up the gas.
Scientists believe some kind of natural process must be cycling the
methane into the atmosphere; from there, it falls back down to the
surface as methane rain, similar to the water cycle on Earth. Since
Titan’s surface is mostly frozen, researchers think any methane rising
into the atmosphere must be coming from a few scattered unfrozen "hot
spots."
The $3.2 billion Cassini mission launched in 1997 and arrived in orbit
around Saturn in 2004. The mission also dropped a probe named Huygens
onto the surface of Titan in January 2005.
How the surface look like in this art photo.The Water is methane which on Earth its a gas but the temp on the surface is very cold.
No comments:
Post a Comment