by Lisa M.A. Winters, contributing writer
In 1996, a Martian meteorite, excavated in Antarctica and known as ‘Allan Hills 84001’, created a stir when analyses suggested it contained evidence for microscopic fossils of Martian bacteria, based on carbonate globules observed in the sample.
Now a team analysing Yamato 000593, which was found in Antarctica by a Japanese team in 2000, have found microscopic structures of a similar nature deep within the 13.5 kilogram space-rock. The paper published in February’s Astrobiology, describes microscopic tunnels that thread their way through the meteorite’s interior, as well as tiny blobs of carbon-rich minerals that are embedded within layers of rock.
Yamato 000593 formed on Mars about 1.3 billion years ago and altered by interaction with water there. The rock was blasted into space by a cosmic impact and fell to Earth within the past 10,000 years. The micro-tunnels and spherules found are suggestive of ancient weathering through biological processes; Terran rocks from the anaerobic deep sea bottom might show similar structures. A quote from the team publishing the analysis cautions hopefully, “textural and compositional similarities to features in terrestrial samples, which have been interpreted as biogenetic, imply the intriguing possibility that the Martian features were formed by biotic activity.”
Analysis of the carbon molecules themselves, which is the next step to be taken by the research team, will provide yet more data for the developing theory.
(left) Micro-tunnels which suggest microbial weathering. (right) Spherules in red circle, as contrasted with background material in blue circle.