The moon’s massive pool of methane, ethane and nitrogen could potentially swallow skyscrapers
“The idea that you can do bathymetry [measure depth] on a moon in the outer solar system is exciting,” says Elizabeth Turtle, a planetary scientist at Johns Hopkins University Applied Physics Laboratory, who was not involved in the new study. The results “are so informative in terms of providing data to understand Titan and to help plan missions there.
The researchers caution that future work might indicate some signals failed to bounce back not because of great depth but because the liquid absorbed more radar energy than they calculated it would. That would suggest their working estimates about composition are off. Based on their calculations, the sea appears to comprise about 70 percent liquid methane, 16 percent liquid nitrogen and 14 percent liquid ethane at a temperature of −182 degrees Celsius. When Cassini swept by, Kraken Mare’s surface waves measured just a few millimeters high.
Depth and composition data are vital for engineers designing robotic submarines and other equipment to eventually journey through Titan’s lakes and seas, says Steven Oleson, an astronautical engineer at nasa’s Glenn Research Center in Ohio, who was also not involved in the study. He and other engineers have put together preliminary designs for such a craft, even though a robotic sub is not currently part of NASA’s mission lineup. Understanding Kraken Mare is critical to understanding Titan overall: the sea holds about 80 percent of the moon’s surface liquid and covers about 500,000 square kilometers—roughly twice the area of North America’s Great Lakes combined.
This article was originally published with the title “Alien Depths” in Scientific American 324, 5, 12-14 (May 2021)
ABOUT THE AUTHOR(S)
Sid Perkins, who writes most often about Earth and plan