It’s arguably the most scrutinised piece of rock ever. Now an even closer look at a meteorite from Mars suggests it may show signs of life after all. …
One area of disagreement centred around nanocrystal magnetites in the rock, some of which appear to have chemical and physical features identical to those produced by contemporary bacteria. Sceptics of the biological explanation suggested that the magnetites were created when carbonate decomposed under high pressures and temperatures, …
Now a fresh analysis by McKay and colleagues rules out the carbonate decomposition explanation. … The possibility that the rock contains fossilised microbes received another boost in August when a team … showed that carbon in the meteorite was deposited in balmy water conducive to life.
Of course this doesn’t directly confirm longer distance panspermia.
Even if that meteorite contains bacterial fossils, which is still dubious, how is that evidence for panspermia?
I find more likely that life could have appeared independently both on the Earth and on Mars, rather than bacteria surviving some terrible explosion jettisoning them to a transfer orbit, then many years (decades? centuries? millennia?) of travel at freezing temperature and no atmosphere and finally an uncontrolled entry in the Earth atmosphere and crash on the ground.
Confirmed does seem a little strong of a word...