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Rehabilitating Mars
Posted Feb. 9, 2005
Courtesy American Geophysical Union
and World Science Staff
Introducing global warming on Mars may be the best way to warm the planet’s frozen landscape and turn it into a liveable world in the future, a team of scientists says.
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It's believed that Mars once may have been
liveable, though today it seems to be dead and mostly dry. The above
image is from NASA's Viking missions to Mars (Courtesy NASA Center for
Mars Exploration)
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The researchers propose that injecting substances known as “super” greenhouse gases into the Martian atmosphere could raise the planet’s temperature enough to do the trick.
But it might take centuries, or longer, they added.
Greenhouse gases are gases that trap heat in the atmosphere. Scientists consider them the major cause of global warming on Earth.
Margarita Marinova, who was with the NASA Ames Research Center when she conducted the studies, and colleagues propose that the same types of atmospheric interactions that have led to recent surface temperature warming trends on Earth could be harnessed on Mars to create another biologically hospitable environment in the solar system.
The researchers, writing in the February issue of Journal of Geophysical
Research-Planets, argued that their method would be more effective than previously mentioned alternatives,
like sprinkling sunlight-absorbing dust on the poles or placing large mirrors in the planet’s orbit.
“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,” Marinova said. “Since warming Mars effectively reverts it to its past, more habitable state, this would give any possibly dormant life on Mars the chance to be revived and develop further.”
The authors noted that artificially created gases—which would be nearly 10,000 times more effective than carbon dioxide, the most common greenhouse gas on Earth—could be manufactured to harm living things only minimally.
They created a computer model of the Martian atmosphere and analyzed four such gases, individually and in combination, that are considered the best candidates for the job.
Their study focused on fluorine-based gases, composed of elements readily available on the Martian surface, that are known to be effective at absorbing infrared heat energy. They found that a compound known as octafluoropropane produced the greatest
warming. Its combination with several similar gases enhanced the warming further.
The researchers anticipate that adding a tiny amount of the gas mixture in the current Martian atmosphere would spark a runaway greenhouse effect, creating an instability in the polar ice sheets that would slowly evaporate the frozen carbon dioxide on the planet’s surface.
They added that the release of increasing amounts of carbon dioxide would lead to further melting and global temperature increases that could then enhance atmospheric pressure and eventually restore a thicker atmosphere to the planet.
Such a process could take centuries or even millennia to complete, Marinova and
colleagues say. But, because the raw materials for the fluorine gases already exist on Mars, astronauts
might be able to create them on a manned mission to the planet. It would otherwise be impossible to deliver the required quantities of the gas to
Mars, the authors said.
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