Life on Mars?:
Life on Mars? In 1996 McKay et al. announced possible evidence of ancient life on Mars.
A Martian meteorite showed ~3 billion years old remnants of organic molecules. Sara Bergenius
sarabe@particle.kth.se
ALH84001:
ALH84001 Martian origin:
unique composition of oxygen isotopes consistent with Martian atmosphere.
Three ages:
4.5 billion years old (oldest of Martian meteorites)
16 million years in space
13000 years on earth
No terrestrial weathering.
Carbon isotopic composition different from weathered meteorites. Sara Bergenius
sarabe@particle.kth.se
Martians=Carbonate pancakes?:
Martians=Carbonate pancakes? Sara Bergenius
sarabe@particle.kth.se Tubes and ovoids,
~10-100 nm. Regions of debate: Carbonate globules, ~1-250 μm. McKay has three arguments:
Mini Martians?:
Mini Martians? Sara Bergenius
sarabe@particle.kth.se Magnetites, ~1-100nm, in rims of carbonate pancakes. High concentration of PAH (Polycyclic Aromatic Hydrocarbons) in carbonate areas.
Synthetic Martians?:
Synthetic Martians? Andrea Koziol reproduced non-biological grains similar to the ones in ALH84001.
Same size, same shape, same slanted edges and same lined-up atoms as in the meteorite.
Method: heat synthetic carbonates to 470ºC for 5 min voilà magnetite.
But, this does not discount the “Life on Mars” theory. Sara Bergenius
sarabe@particle.kth.se
Summary:
Summary Are the magnetite crystals remnants of magnetotactical bacteria?
Strong magnetic field on early Mars?
5 out of 6 criterias are fulfilled.
Extraordinary claims requires extraordinary evidence. Sara Bergenius
sarabe@particle.kth.se