Human beings are always asking questions and exploring the planet that we live on. Our curiosity is not just limited to the earth, however, but extends beyond our solar system and includes as much of the universe that we can imagine. This explains our constant search for life on other planets and prompts us to find different ways to prove to ourselves that it does exist. Sometimes we do not even have to look outside the planet as evidence of this extra-terrestrial existence has, literally, fallen at our feet. Meteorites that may contain traces of life from other planets have been carefully tested, and in some cases the results have strongly indicated that this life exists.
The Orgueil Meteorite is one of a rare group, called carbonaceous meteorites. It fell to France in 1864 and was recently examined, along with 8 others in the same group, by Richard B Hoover who reported that they contained ‘indigenous fossils’ of bacterial life. This means that there is the high possibility of life existing on comets, which bring water and other life supporting elements with them when they fall to our planet. Hoover’s main supporting argument is the fact that the fossils are imbedded in the rock in a way that indicates that they must have been there before its entry into our atmosphere.
Another meteorite, Tissint, landed in the Moroccan desert in 2011. It is believed to have been thrown from the surface of Mars about 700,000 years ago. There are tiny fissures on its surface which contain material, deposited by water, which is obviously biological in origin. Conclusions that led researchers to believe that the compound is not of this world are:
- There was a very short time between the meteorite’s impact and recovery, and the imbedding of this material would only have been possible over a much longer time span.
- The microscopic fissures in its surface could only be produced by a sudden, very intense heat which would not have been possible in the Moroccan desert.
- There were also carbon grains (diamonds) in the rocks surface and no known conditions in the desert would have been able to produce these.
- In the carbon there is a high amount of deuterium, which is exactly like the composition of Mars’ geology.
Fragments of a meteorite, called the Polonnaruwa Meteorite, landed in Sri Lanka in December 2012. The country tested it and found diatoms (siliceous microalgae) in the fragments. To confirm their original tests the meteorites were sent to Cardiff University in Wales, where researchers noted that fossilized biological structures are definitely present. Low levels of nitrogen (which is always present in terrestrial organisms), oxygen isotope analysis and the fact that the fossils are fused within the rock are all strong indicators that they come from extra-terrestrial organisms.
Panspermia is the theory that life came to earth via a meteorite containing simple organisms, billions of years ago. More research into these meteorites, and a clear conclusion about the origin of the life that they contain, may be a major deciding factor in whether or not the concept of panspermia will remain a theory or become a reality.