Although surface temperatures on Titan are cold enough that methane can exist as a liquid, filling lakes and flowing in streams, it may sometimes get so cold that even the liquid methane and ethane freezes, forming floes and icebergs of frozen hydrocarbons. This Titanic revelation was announced today during the 221st American Astronomical Society meeting in Long Beach, CA.
No, you’re not looking down at the Amazon or the Nile (although the confusion would be understandable)… this is actually a river on an entirely different world: Saturn’s moon Titan! Radar imaging by NASA’s Cassini spacecraft has revealed what appears to be a long river system, complete with side-branching tributaries, meandering across the surface of Titan.
Of course on frigid Titan the river wouldn’t be flowing with water but rather liquid methane and ethane — quite literally a river of natural gas. Water on Titan’s surface stays frozen harder than rock and what’s a gas here on Earth is cold enough to be a thick, viscous liquid there, 880 million miles from the Sun.
See the full-size image and read more below:
Back in December of 2001, Saturn’s moon Titan passed in front of two background stars (called an “occultation”) from the point of view of the Hale Telescope at Palomar Observatory. Astronomers used the incredible resolving ability of the 5-meter telescope’s adaptive optics to watch the event, which revealed the diffraction of the stars’ light through Titan’s dense atmosphere as well as allowing them to measure the moon’s stratospheric winds. Check it out above!
Video credit: A. Bouchez, M. Brown, M. Troy et al./Caltech
Titan just never ceases to amaze. Saturn’s largest moon, it’s wrapped in a complex, multi-layered nitrogen-and-methane atmosphere ten times thicker than Earth’s. It has seasons and weather, as evidenced by the occasional formation of large bright clouds and, more recently, an area of open-cell convection forming over its south pole. Titan even boasts the distinction of being the only other world in the Solar System besides Earth with large amounts of liquid existing on its surface in the form of exotic methane lakes and streams.
We can thank NASA’s Cassini spacecraft for these discoveries, in orbit around Saturn since 2004, and now there’s one more for the tireless explorer to add to its ever-growing list: Titan glows in the dark.
A color-composite image of Titan shows Saturn’s largest moon in true color, including its recently-discovered southern vortex forming above its south pole.
The image was assembled from three raw images acquired on August 28 by NASA’s Cassini spacecraft in red, green and blue visible light color channels. The background was extended in size to better frame the moon.
Thanks to Cassini’s new vantage point granted by its inclined orbit researchers have gotten a new look at the south pole of Titan, Saturn’s largest moon. What they’ve recently discovered is a swirling vortex of gas forming over the moon’s pole, likely the result of the approach of winter on Titan’s southern hemisphere.
The pumpkin-orange colors of Titan’s thick clouds appear in stark contrast in front of the limb of Saturn, which appears quite blue along its sunlit limb due to Rayleigh scattering, the same process that makes the sky look blue here on Earth.
The image here is a color composite made from three separate raw images acquired by Cassini on July 1, 2012. Captured in red, green and blue visible light wavelengths, when combined the result is a more-or-less true color image as our eyes might see it. The final image was rotated to make the angle of sunlight come in from the left horizontally, and I teased out some detail in Saturn’s atmosphere.
Cassini was over 1.7 million miles from Titan when the images were captured.
Credit: NASA/JPL/SSI. Edited by J. Major.
On a related note, today another Saturn/Titan color composite I assembled in May was chosen for the popular Astronomy Picture of the Day page, or APOD as it’s known. Check it out here. The image first appeared on Universe Today on May 11, and was thereafter picked up by ESA and from there made its way to APOD. Very cool!