January 20, 2018
Researchers using data from the NASA mission Cassini have discovered a surprising similarity between Earth and Earth Saturn's moon Titan. Just as the surface of the Earth's oceans is at an average elevation called "sea level", the seas of Titan are also at an average elevation. Titan is the only world in our solar system besides the Earth known to have stable liquid on its surface. Instead of water, the lakes and seas of Titan are full of hydrocarbons, mainly methane and ethane. Aquatic ice, covered by a layer of solid organic material, forms the bedrock that surrounds these lakes and seas.
The new study, which was published in the journal Geophysical Research letters, found that the seas of Titan follow a constant elevation relative to the pull of Titan. The smaller lakes of Titan are at elevations several hundred feet, or meters above sea level of the moon. On Earth, lakes are commonly found at high altitudes. Lake Titicaca is more than 12,000 feet (3,700 meters) above sea level.
"We are measuring the elevation of a liquid surface in another body to 10 astronomical units of the Sun with an accuracy of approximately 40 centimeters, because we have an amazing precision, we could see that between these two seas the elevation varied smoothly around 11 meters, in relation to the center of mass of Titan, in line with the expected change in gravitational potential, we are measuring the geoid of Titan, this is the form that the surface would take under the influence of gravity and rotation, which it is the same shape that dominates Earth's oceans, " said Alex Hayes, assistant professor of astronomy at Cornell University in Ithaca, New York through a release.
Another finding presented in the new study is that Titan's liquid bodies appear to be connected below the surface by means similar to an aquifer system on Earth. The hydrocarbons seem to move beneath Titan's surface in a manner similar to the way water flows through porous rock or gravel on Earth. This is similar to the way the neighboring lakes communicate with each other. each other and maintain a common liquid level.
The study used data collected by Cassini radar instrument until a few months before the spacecraft was ordered to burn in Saturn's atmosphere last fall. The researchers also made use of a new topographic map of Titan that was published in the same issue of Letters of geophysical research as the study.
It took about a year to create the map, according to Cornell's Ph.D. student Paul Corlies, lead author of "The topography and shape of Titan at the end of the mission Cassini ." The map combines all the topography of Titan available from multiple sources.
The map also revealed new mountains, none higher than approximately 2,297 feet (700 meters) and other new features in the smoggy moon. This new tool helped reveal that Titan is a bit flatter, more Oblate, than previously thought, indicating that there is more variability in the thickness of Titan's crust than previously thought.
"The main objective of the work was to create a map for the use of the scientific community," said Corlies, who began receiving inquiries about how to use the map in 30 minutes from the availability of the online data set.
Video courtesy of NASA / JPL
Jim Sharkey is a laboratory assistant, writer and general science enthusiast who grew up in Enid, Oklahoma, the hometown of astronaut Skylab and Shuttle Owen K. Garriott. As a young Star Trek fan, he participated in the letter writing campaign that resulted in the space shuttle prototype being called Enterprise.
While his academic studies range from psychology and archeology to biology, he has never lost his passion for space exploration. Jim started blogging about science, science fiction and futurism in 2004.
Jim resides in the San Francisco Bay area and has attended NASA's social gatherings for the landing of the Curiosity rover from the Mars Science Laboratory and the launch of NASA's LADEE lunar orbiter.