Related? Unrelated? Good? Bad? The long hot Summer on the red planet. What if the ice melts? The Times of Londo says its getting hot; the BBC says there is ice enough for an ocean. Sail the Martian Sea? Henry_Allen
From The Sunday Times
April 29, 2007
Climate change hits Mars
Mars is being hit by rapid climate change and it is happening so fast that the red planet could lose its southern ice cap, writes Jonathan Leake.
Scientists from Nasa say that Mars has warmed by about 0.5C since the 1970s. This is similar to the warming experienced on Earth over approximately the same period.
Since there is no known life on Mars it suggests rapid changes in planetary climates could be natural phenomena.
The mechanism at work on Mars appears, however, to be different from that on Earth. One of the researchers, Lori Fenton, believes variations in radiation and temperature across the surface of the Red Planet are generating strong winds.
In a paper published in the journal Nature, she suggests that such winds can stir up giant dust storms, trapping heat and raising the planet’s temperature.
Fenton’s team unearthed heat maps of the Martian surface from Nasa’s Viking mission in the 1970s and compared them with maps gathered more than two decades later by Mars Global Surveyor. They found there had been widespread changes, with some areas becoming darker.
When a surface darkens it absorbs more heat, eventually radiating that heat back to warm the thin Martian atmosphere: lighter surfaces have the opposite effect. The temperature differences between the two are thought to be stirring up more winds, and dust, creating a cycle that is warming the planet.
| By Neil Bowdler BBC News |
The new method of scanning for water offers vastly more accurate readings than before, they say.
The data could prove vital for the Phoenix Mars Mission which launches this August and which will put a lander on the surface to dig for ice.
The new data shows wide variation as to how deep below the surface ice exists.
Seasonal changes
The deposits - far beyond the ice that is known to exist in the planet's North Pole - could be so large that were they to melt, they would deluge the planet in water forming an ocean.
Up until now, scientists had been able to search for water deposits using a spectrometer fixed to the orbiting Mars Odyssey spacecraft.
It is a device that measures nuclear radiation coming from a planet to detect different materials.
However, only readings that are accurate to within several hundred kilometres can be obtained.
Now Dr Joshua Bandfield of Arizona State University has devised a new method for detecting ice.
By comparing seasonal changes in thermal infrared patterns, detected by the same Odyssey spacecraft, he says he can make readings accurate to within just hundreds of metres.
Dr Bandfield said water ice in terms of surface area would be "probably roughly a third to a half".
Though there is plenty of water ice, the new thermal imaging data also shows that there is considerable variation across the planet in terms of how far down ice can be found.
http://news.bbc.co.uk/go/pr/fr/-/2/hi/science/nature/6617851.stm
Published: 2007/05/02 22:17:13 GMT
© BBC MMVII
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