Nasa Web New Nasa Evidence Points To Biological Processes Active On Mars Hundreds Of Millions Of Years Ago
Evidence of past water movement throughout a Martian meteorite, reviving debate in the scientific community over life on Mars, has been disdcovered by a team of scientists at NASA'sJohnson Space Center in Houston and the Jet Propulsion Laboratory. In 1996, a group of scientists at Johnson led by David McKay, Everett Gibson and Kathie Thomas-Keprta published an article in"Science" announcing the discovery of biogenic evidence in the Allan Hills 84001(ALH84001) meteorite. In this new study, Gibson and his colleagues focused on structures deep within a 30-pound (13.7-kilogram) Martian meteorite known as Yamato 000593 (Y000593). The team reports that newly discovered different structures and compositional features within the larger Yamato meteorite suggest biological processes might have been at work on Mars hundreds of millions of years ago.Analyses found that the rock was formed about 1.3 billion years ago from a lava flow on Mars. Around 12 million years ago, an impact occurred on Mars which ejected the meteorite from the surface of Mars. The meteorite traveled through space until it fell in Antarctica about 50,000 years ago. The rock was found on the Yamato Glacier in Antarctica by the Japanese Antarctic Research Expedition in 2000. The meteorite was classified as a nakhlite, a subgroup of Martian meteorites. Martian meteoritic material is distinguished from other meteorites and materials from Earth and the moon by the composition of the oxygen atoms within the silicate minerals and trapped Martian atmospheric gases."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," said White. "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. As more Martian meteorites are discovered, continued research focusing on these samples collectively will offer deeper insight into attributes which are indigenous to ancient Mars. Furthermore, as these meteorite studies are compared to present day robotic observations on Mars, the mysteries of the planet's seemingly wetter past will be revealed."The team found two distinctive sets of features associated with Martian-derived clay. They found tunnel and micro-tunnel structures that thread their way throughout Yamato 000593. The observed micro-tunnels display curved, undulating shapes consistent with bio-alteration textures observed in terrestrial basaltic glasses, previously reported by researchers who study interactions of bacteria with basaltic materials on Earth
