Polar caps wane as Mars tries global warming
All those little green men in their 4x4s
Global warming and melting polar ice caps are not just problems here on Earth. Mars is facing similar global changes, researchers say, with temperatures across the red planet rising by around 0.65 degrees over the last few decades.
The trigger for the changes on Mars are, however, totally different from those mechanisms controlling and influencing climate here on Earth. Researchers at the Carl Sagan centre in Mountain View, California, suggest that the planet's albedo, how much light it reflects, is a major factor in the warming.
Lori Fenton explains that current maps of the planet show it is much darker than it was in the late seventies, especially around the southern highlands.
Fenton explains that much of the lighter coloured dust that covers the planet has been swept aside by Martian dust devils, leaving the much darker bedrock exposed to the sun. This darker land holds the heat much more efficiently, warming the planet. in turn, this warming triggers stronger winds, exposing even more bedrock.
Phil Christensen, a planetary scientist at Arizona State, cautions against over-extrapolating from the data, however. He told Nature.com that it is unlikely that in 500 years time the Martian ice caps would be completely gone:
"They're looking at a piece of the cycle, other processes could turn this around to a place where the ice-caps start growing again. You can't take 10 years of data and extrapolate out to 1,000 years."
Christensen also cautions against drawing any parallels between the warming on Mars and on Earth. He said: "The more we learn about Mars, the more intuition it gives us about Earth, but the systems are fundamentally different."
Meanwhile, other researchers are sceptical about the scale of the change that Fenton has calculated, pointing out that different instruments measured the planet's albedo in the 70's and now. ®