APOD
Astronomy Picture of the Day
Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.
Mystery Feature Now Disappears in Titan Lake
Explanation: What is that changing object in a cold hydrocarbon sea of Titan? Radar images from the robotic Cassini spacecraft orbiting Saturn have been recording the surface of the cloud-engulfed moon Titan for years. When imaging the flat -- and hence radar dark -- surface of the methane and ethane lake called Ligeia Mare , an object appeared in 2013 July just was not there in 2007. Subsequent observations in 2014 August found the object remained -- but had changed. In an image released last week, the mystery object seems to have disappeared in 2015 January. The featured false-color image shows how the 20-km long object has come, changed, and gone. Current origin speculative explanations include waves , bubbling foam and floating solids , but still no one is sure. Future observations , in particular Cassini's final close flyby of Titan in 2017 April, may either resolve the enigma or open up more speculation.
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| Date | March 7, 2016 |
|---|---|
| Credit | Image Credit: Cassini Radar Mapper , Cornell , JPL , ESA , NASA |
| Authors & editors: | Robert Nemiroff (MTU) & Jerry Bonnell (UMCP) |
| A service of: |
ASD at NASA / GSFC, NASA Science Activation & Michigan Tech. U. |



