Last updated: June 14, 2012 3:10 pm
University of Alberta prof helps verify source of organic Martian material
EDMONTON (CUP) — Thanks to the contribution of a researcher at the University of Alberta, speculation over the origin of a mysterious organic compound found in Martian meteorites has been put to rest.
A recent study investigated the presence of an organic compound in Martian meteorites that landed on Earth. What this study revealed, however, is that the carbon found in these meteorites originated from Mars’ mantle layer — the region between the planet’s crust and the core — and not as the result of any life activity.
Chris Herd, an associate professor for the Department of Earth and Atmospheric Sciences at the U of A and an expert in interpreting Martian meteorites, contributed to the study by looking at the conditions that helped to preserve this organic material in the rocks.
Unlike graphite, which is made entirely out of carbon, Herd found that the compound in the Martian samples contains other components, like hydrogen, that make it organic and usable in biological processes.
“It’s like the material that life either uses or produces,” Herd said. “So in that sense it was definitely a surprise to find it in there.”
According to Herd, all Martian meteorites that have landed on Earth are igneous rocks that began as magma — molten rock deep below the planet’s surface. The magma is then pushed to the surface as a lava flow, much like volcanic eruptions that happen on Earth.
Once above ground, the rock cools and settles before being ejected from the surface by some force, like an asteroid collision, which sends it hurtling into space to make its way towards our planet.
“The significance of the study is that the carbonaceous material — the carbon rich material — was actually found locked up inside the crystals that formed as the rock was cooling off in the lava flow,” Herd said.
Unlike Earth, Mars does not have plate tectonics that cycle carbon by pushing crust material back into the mantle. This one-way flow of carbon suggests that this material is coming from inside Mars itself, and has been there since the planet formed more than 4 billion years ago.
Because weathering processes, like those caused by wind and water, break down these igneous rocks and release carbonaceous content onto the surface, it is expected that NASA’s Curiosity Rover, due to land on Mars this August, will encounter the organic material in its search for signs of Martian life.
“It could confuse things and say that we found evidence of life when we’ve shown in this study that it has nothing to do with life,” Herd said.
“The timing of this study is good in that it shows that there’s this additional source of carbonaceous material, and it’s something that the team members of the Curiosity mission should be aware of.”