The effect may have gotten out of hand, turning the planet into a wasteland

May 24, 2012 07:54 GMT  ·  By

Eons ago, Mars underwent a period in which asteroid strikes were commonplace. Astronomers now propose that the large number of collisions may have been one of the primary factors that drove temperatures on the planet through the roof, eventually leading to a runaway global warming effect.

Understanding what happened on the neighboring world is absolutely essential to figuring out why Mars, once a place where life could have arguably thrived and developed, is now a barren wasteland.

Geological evidence suggests that not only did the Red Planet have lakes, rivers and deltas containing liquid water on its surface, but that a large ocean existed in its northern hemisphere. All that water is now gone, partially lost through the atmosphere, and partially buried in ice caps at the poles.

At this point, scientists can safely say that Mars was once a place suitable for life. However, that is no longer the case, and the runaway global warming effect definitely had a hand in this transformation.

Studies of the Argyre basin, an impact crater 1,140 kilometers (710 miles) wide and 3.8 billion years old, suggest that the collision which created it released the energy of around 100 billion megatons of TNT, and raised surface temperatures by hundreds of degrees.

The impact was a lot more powerful than the collision that triggered the Cretaceous-Paleogene (K-T) extinction event that killed off the dinosaurs here on Earth. The object responsible for the event is believed to have been around 100 to 200 kilometers (60 to 120 miles) in diameter.

What new studies are suggesting is that the high temperatures caused by such blasts may have not subsided over time, as initially proposed, but rather went on to produce a warm climate that was stable in the long term, Astrobiology Magazine reports.

“Any terrestrial planet, including Venus, the Earth, or even exoplanets, may have experienced a temporary or permanent runaway greenhouse climate caused by impacts,” Space Systems/Loral researcher and planetary scientist, Teresa Segura, explains.

In a paper published in the May 2 online issue of the journal Icarus, researchers say that if an impactor the size of the one that created the Martian Argyre basin would hit Earth, then there would be no one left to analyze the prospective effects the collision would have on our planet's climate.