14 DAY TRIAL // Though it may seem somewhat unlikely, some of the meteorites that fall to Earth are actually pieces of rock from other planets. Several fragments have been found, for example, to originate on the Red Planet, and their analysis is what laid the foundation for studies claiming to have found evidence of fossilized life forms on the planet. Now, a minute rock called Nakhla could provide investigators with the data they need to unravel the intricate mystery that is Mars' water history, PhysOrg reports.
Over the past few years, as orbiters and rovers have been roaming on and around the planet, numerous signs hinting at the fact that water once flew freely – and in liquid form – on the Red Planet have emerged. Spirit and Opportunity, the two robots of the Mars Exploration Rover (MER) program, and the Mars Reconnaissance Orbiter (MRO) have all supplied experts with irrefutable proof that liquid water must have at one time existed in liquid form. Some geologists and planetary scientists even believe that an ocean may have existed on the northern hemisphere, although its existence has yet to be proven conclusively.
Until new and powerful tools such as the rover Curiosity are deployed to Mars, researchers will just have to make do with meteorites they've established as originating from the planet. And Nakhla is giving them enough to work with. Despite its reduced size, the rock could hold the key to how and when liquid water existed on the planet. Scientists from the University of Glasgow are currently looking for traces of various minerals in the rock, in the hope of finding some that may have formed in the presence of water alone. Given the porous nature of the meteorite, they say that water may have brought the chemicals making up the minerals inside the rock. Over eons, the chemicals crystallized, forming the minerals. The group is using electron microscopes to carry out this task.
“When the minerals crystallize they contain certain elements which are radioactive and therefore decay over time – potassium, for example, which decays to form argon. By measuring the levels of argon we are able to determine roughly when the minerals grew and hence when the water deposited them there. Meteorites like this offer the best way of analyzing the Martian environment and geological history as there’s more of Mars on Earth than we could ever bring back from the planet itself. It’s possible that we might even find bits of water trapped within rocks, and maybe some traces of organic material within that,” explains UG Geographical and Earth Sciences Department senior lecturer Dr Martin Lee, the leader of the new study.