Meteorite Proves Mars Had Volcanoes For 2 Billion Years
Scientists recently discovered that Mars had volcanoes for at least 2 billion years, making it home to the oldest known volcanoes ever in the Solar System, thanks to a study of a Martian meteorite found in Alegria in 2012.
The meteorite, called Northwest Africa 7635 (NWA 7635), was found to be composed of shergottite, a volcanic element known to be Martian. Popular Mechanics noted that the element has always been difficult to age because it has been crystallized 180 million years ago, leading people to believe that the shergottite that landed on Earth can only be traced back to a core event -- when something slammed into Mars and things ricocheted to the planet Earth.
Analysis of the 6.9-ounce meteorite helped determine that a single volcano has erupted continuously for more than 2 billion years. Meteorites such as the NWA 7635 were the reason humans had something about the Red Planet to study despite the fact that no human has ever landed there.
Over 100 meteorites ever collected around the world have been identified as Martian. Purdue University noted that thanks to the lower gravitational attraction of Mars, as well as its thinner atmosphere, that it is now easier for fragments to be released during impacts.
Unfortunately, it is not a direct path, and rock fragments orbit space for hundreds of thousands of years, at least. Once they arrive on Earth, they begin to degrade -- ultimately becoming unrecognizable as extraterrestrial rock.
The NWA 7635 came with 10 other meteorites that are about 500 million years old. But it was different from them in a sense that it is 2.4 billion years old. Mars is known to have the most magnificent volcanoes in the Solar System. Olympus Mons, for instance, is a massive shield volcano 17 miles tall, so it is truly just a matter of questioning when they had formed.
"These meteorites are allowing us to conduct geologic science on the surface of Mars, and we haven't even been there yet," Marc Caffee, a member of the research team from Purdue University, said.