FRED ANSWERS YOUR QUESTIONS
I’ve heard that Saturn’s moon Titan is a model for the early Earth. What does this mean? Steve Wishart, Hawthorn, VIC
Titan’s distance from the Sun makes it a very cold world, with a temperature of about –180oC, and a surface made of rock-hard ice. But its similarities to Earth include a thick atmosphere, with clouds and rain. The raindrops are not water, but liquid methane and ethane, which pools into lakes and seas – the only ones known beyond our own planet. This strange world could sustain microorganisms based on hydrocarbons rather than water, making it an analogue of the young Earth. Future space probes will target the seas of Titan in the search for life.
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