Ray Moscow
05 Jun 2009, 09:39 AM
I attended a talk on Mars by Alan Longstaff last night. Dr. Longstaff is a scientist working at the Royal Observatory and a lecturer at the Open University. He also writes the "Ask Alan" column in Astronomy Now.
Anyway, he cited several points of evidence that indicate that although there was free water flowing on Mars in its early days, this probably hasn't been the case for the past 4 billion years or so. One implication is that there isn't much chance of finding extant life on Mars, if there ever was any (as it the window for life to evolve there is pretty short).
The most likely scenario is that something about the size of our moon smashed into the northern hemisphere about 4 billion years ago, radically changing Mars.
So, no Martians are likely to pop up, except maybe some microbial ones or remnants thereof.
ETA: Here's an article (http://www.wonderquest.com/mars-water.htm) that discusses a few of the issues, with some of Longstaff's comments.
Anyway, he cited several points of evidence that indicate that although there was free water flowing on Mars in its early days, this probably hasn't been the case for the past 4 billion years or so. One implication is that there isn't much chance of finding extant life on Mars, if there ever was any (as it the window for life to evolve there is pretty short).
The most likely scenario is that something about the size of our moon smashed into the northern hemisphere about 4 billion years ago, radically changing Mars.
So, no Martians are likely to pop up, except maybe some microbial ones or remnants thereof.
ETA: Here's an article (http://www.wonderquest.com/mars-water.htm) that discusses a few of the issues, with some of Longstaff's comments.