Greenhouse gases could breathe life into Mars
17:49 04 February 2005
Pumping greenhouse gases into the Martian atmosphere over hundreds or even thousands of years could warm the frozen planet enough to sustain life, according to new research.
Synthetic fluorine-based gases could produce global warming on Mars while also creating an atmosphere conducive to life, say scientists at the NASA Ames Research Centre, California, US.
Conditions on Mars are currently inhospitable for advanced life. Temperatures on the Red Planet currently dip down to -120°C at night near the poles. And the atmospheric pressure on Mars is much less than on Earth as its atmosphere is thinner and its gravity lower.
In order to support life, scientists have proposed transforming Mars into an Earth-like planet in a process called terraforming. And a crucial component of this would be to warm up the planet.
The study found four fluorine-based gases that could be made of elements abundant on the Martian surface. Fluorine excels at absorbing thermal energy. In addition, the gas does not destroy ozone, unlike the greenhouse gases bromine and chlorine.
Runaway effects
Using computer models, researchers found that a gas called octafluoropropane (C3F8) produced the greatest warming in their study. The gas also worked well when mixed with other gases.
Adding this gas so that its concentration in the Martian air was 300 parts per million could spark a runaway greenhouse effect by evaporating the polar ice caps, which are composed of carbon dioxide. That extra CO2 - a greenhouse gas itself - would lead to even more melting and warming. This could help thicken the Martian atmosphere and increase atmospheric pressure.
But this amount represents 25,700 times Earth's annual production of fluorine- and carbon-based gases.
Cosmic vandalism
Some of the competing alternatives to adding gas to the planet would be to sprinkle sunlight-absorbing dust on the poles to try to melt the ice caps, or putting large mirrors into orbit to reflect sunlight onto the surface. But the Ames scientists said adding gas would be more effective than these options.
"Bringing life to Mars and studying its growth would contribute to our understanding of evolution, and the ability of life to adapt and proliferate on other worlds," says Margarita Marinova, the study's lead author.
But terraforming has many critics who debate the ethics of altering another planet. "In principle, it's something which is possible but which I would not advocate," says Andrew Coates at the University College London, UK. He works on the Mars Express spacecraft's ASPERA instrument, which analyses the interaction between the solar wind and Mars's atmosphere. "It's the ultimate in cosmic vandalism; at least until we completely understand the conditions for past or present life on Mars, and we are 100% sure that none is there now."
"These are 20th-century ideas on how to approach a late 21st-century, early 22nd-century problem," says Robert Zubrin, president of the Mars Society in Colorado, US. The new study simply shows that warming Mars in this way might be possible, he says.
http://www.newscientist.com/article.ns?id=dn6973
17:49 04 February 2005
Pumping greenhouse gases into the Martian atmosphere over hundreds or even thousands of years could warm the frozen planet enough to sustain life, according to new research.
Synthetic fluorine-based gases could produce global warming on Mars while also creating an atmosphere conducive to life, say scientists at the NASA Ames Research Centre, California, US.
Conditions on Mars are currently inhospitable for advanced life. Temperatures on the Red Planet currently dip down to -120°C at night near the poles. And the atmospheric pressure on Mars is much less than on Earth as its atmosphere is thinner and its gravity lower.
In order to support life, scientists have proposed transforming Mars into an Earth-like planet in a process called terraforming. And a crucial component of this would be to warm up the planet.
The study found four fluorine-based gases that could be made of elements abundant on the Martian surface. Fluorine excels at absorbing thermal energy. In addition, the gas does not destroy ozone, unlike the greenhouse gases bromine and chlorine.
Runaway effects
Using computer models, researchers found that a gas called octafluoropropane (C3F8) produced the greatest warming in their study. The gas also worked well when mixed with other gases.
Adding this gas so that its concentration in the Martian air was 300 parts per million could spark a runaway greenhouse effect by evaporating the polar ice caps, which are composed of carbon dioxide. That extra CO2 - a greenhouse gas itself - would lead to even more melting and warming. This could help thicken the Martian atmosphere and increase atmospheric pressure.
But this amount represents 25,700 times Earth's annual production of fluorine- and carbon-based gases.
Cosmic vandalism
Some of the competing alternatives to adding gas to the planet would be to sprinkle sunlight-absorbing dust on the poles to try to melt the ice caps, or putting large mirrors into orbit to reflect sunlight onto the surface. But the Ames scientists said adding gas would be more effective than these options.
"Bringing life to Mars and studying its growth would contribute to our understanding of evolution, and the ability of life to adapt and proliferate on other worlds," says Margarita Marinova, the study's lead author.
But terraforming has many critics who debate the ethics of altering another planet. "In principle, it's something which is possible but which I would not advocate," says Andrew Coates at the University College London, UK. He works on the Mars Express spacecraft's ASPERA instrument, which analyses the interaction between the solar wind and Mars's atmosphere. "It's the ultimate in cosmic vandalism; at least until we completely understand the conditions for past or present life on Mars, and we are 100% sure that none is there now."
"These are 20th-century ideas on how to approach a late 21st-century, early 22nd-century problem," says Robert Zubrin, president of the Mars Society in Colorado, US. The new study simply shows that warming Mars in this way might be possible, he says.
http://www.newscientist.com/article.ns?id=dn6973
