Martian meteorite may not contain ancient alien life after all

A chemical reaction may have be the source of life found in the Martian meteorite that many thought held ancient alien life some scientists are saying. 

The Martian meteorite (named ALH84001), one of many chunks of rock hurled off of our red neighbor due to impacts, was found to have contained micro particles of carbonate, linked in chains. Some think that this is a remnant of ancient Martian life.

But new studies have shown researchers that similar carbonates can form on Earth without interference from organisms. The process is one they believe to be possible on Mars as well. 

It comes down to Oxygen.  An isotope found named Oxygen -17 was discovered at very high levels inside of ALH84001. These same levels were discovered on Earth in dust and dirt aerosols here on Earth by atmospheric chemist Robina Sharheen at the University of California at San Diego.

This isotope found the low levels of Ozone, a triatomic molecule consisting of three oxygen atoms, have the ability to interact with aerosols from minerals and dust in the form of carbonates possessing the same Oxygen-17 isotope.

The Mars Phoenix Lander detected carbonates linked to particles in the atmosphere on Mars. Sheehan says "We think it might be this same mechanism that is operating,”

This does not rule out the possibility of past or present life on Mars however. If anything we are learning more about Earth’s past. This changes previous ideas that the Earth’s atmosphere is based solely on the mixture of gases. Chemically transformed atmospheric conditions can have effects on rainfall and climate changes we were previously unaware of. 

Even greater is the ability we now have to see how the atmosphere was in the past. The levels in the atmosphere at the time the dinosaurs became extinct for example. This could answer a big piece of the puzzle as to why they became extinct. We currently don’t know the atmospheric change during that time.

The oldest-known SNC meteorite. ALH 84001 originated on the surface of Mars, is gray-green in color, measures 15 × 10 × 8 cm (6 × 4 × 3 in.), and weighs 1.94 kg (4.2 lb). It was recovered by a team from the ANSMET program on Dec. 27, 1984, from the Allan Hills region of Antarctica, where it had lain undisturbed since its arrival on Earth about 13,000 years ago.

This high resolution transmission electron microscope image is of a case, or replica, from a chip of ALH84001. It shows the outline of what are believed to be possible microscopic fossils of bacteria-like organisms. The image was accomplished using a replica, coating the area with a casting substance and then removing it and imaging the case, to avoid the decomposition of features in the electron beam. The replicas consist of a thin platinum-carbon film and supporting carbon film. The tubular features in this image are less than a micrometer in size, or about 1/500th the diameter of a human hair.