A Martian meteorite, Yamato 000593, is reigniting the debate over possibility of existence of alien life on the Red Planet.
Thin sections of the 30-pound meteorite was carefully scrutinized, using a scanning electron microscope. The images revealed tunnels and curved microtunnels, which could have been created by ancient, microscopic lifeforms.
The study of Y000593 was led by David McKay, Everett Gibson and Kathie Thomas-Keprta of NASA's Johnson Space Center.
"While robotic missions to Mars continue to shed light on the planet's history, the only samples from Mars available for study on Earth are Martian meteorites. On Earth, we can utilize multiple analytical techniques to take a more in-depth look into meteorites and shed light on the history of Mars. These samples offer clues to the past habitability of this planet... [A]s these meteorite studies are compared to present day robotic observations on Mars, the mysteries of the planet's seemingly wetter past will be revealed," Lauren White at Jet Propulsion Laboratory, lead author of the study, said.
The rock formed from a lava flow on the Red Planet 1.3 billion years ago. Sometime around 12 million years ago, an asteroid impact on Mars threw the rock into space, headed for the Earth. For millions of years, the boulder traveled the the darkness of space before landing in Antarctica 50,000 years ago.
In 2000, it was discovered on the Yamato Glacier by a team of Japanese researchers.
Micro-tunnels seen in the meteorite twist and turn, as they wind their way through the material. These are similar in appearance to features created by bacteria in basaltic glass. Sandwiched between layers of the meteorite are tiny spherules - tiny beads of carbon rich iddingsite, a form of olivine.
"We also observed microtubular features emanating from iddingsite veins penetrating into the host olivine comparable in shape to those interpreted to have formed by bioerosion in terrestrial basalts," the team wrote in the study, announcing the findings.
On Earth, iddingsite is created from weathering of basalt in the presence of liquid water. The mineral contains clay, ferrihydrite (a form of iron subjected to water in oxygen-rich environments), and iron oxide. That substance, commonly known as rust, makes up 25 percent of the surface of Mars, giving the planet its distinctive red color.
Although the tunnels and curved micro-tunnels could be explained without the presence of life, similarities to markings made by bacteria on Earth are igniting debate once again about life on the Red Planet.
In 1996, structures discovered in another Martian meteorite - Alan Hills 84001 - appeared to be alien fossils. That announcement ignited public excitement about Mars.
Examination of the mysterious meteorite and the accompanying micro-channels have been profiled in the journal Astrobiology.