Leonard David's INSIDE OUTER SPACE

Full Moon…full of Earth fossils?
Credit: NASA/JPL

New research suggests that it is possible that terrestrial rocks ejected from the Earth by giant impacts from space — and which then strike the Moon — may successfully transfer terrestrial fossils to the Moon.

The results were obtained from hypervelocity impact experiments which fired fossilized diatoms frozen in ice into water targets. Diatoms are unicellular, photosynthesizing algae encased in a shell of silica, called the frustule. They readily make recognizable fossils.

After the shots, the material recovered from the target water was inspected for diatom fossils.

Nine shots were carried out at various speeds, corresponding to mean peak pressures. In all cases, fragmented fossilized diatoms were recovered, but both the mean and the maximum fragment size decreased with increasing impact speed and hence peak pressure.

The upshot of the research is that it adds to “a growing body of work that demonstrates that material of interest regarding the origin and distribution of life in the Solar System can survive impacts,” the researchers suggest.

Results from a high speed test shot. Large area images are shown in (a–c) and include whole diatoms fossils. Close up images of smaller fragments of diatom fossils are shown in (d–f).
Credit: Mark Burchell, et al, the Center for Astrophysics and Planetary Science, School of Physical Sciences, Canterbury, Kent/UK

While there have been suggestions by others that the Moon is a good place to look for terrestrial meteorites which contain fossils, the new findings demonstrate that this is indeed viable.

This intriguing research is detailed in the paper “Survival of fossils under extreme shocks induced by hypervelocity impacts,” carried in the Philosophical Transactions of the Royal Society A, a journal devoted to a specific area of the mathematical, physical and engineering sciences.

The research was done by University of Kent physicists, led by Mark Burchell at the Center for Astrophysics and Planetary Science, School of Physical Sciences, Canterbury, Kent, in the United Kingdom.

The full research paper can be accessed by going to:

http://rsta.royalsocietypublishing.org/content/372/2023/20130190.full