Many of us have often looked at the stars on a clear night and wondered about our origins. Why am I here and where did life come from? There is a theory that postulates that the stars might have been the right place to be looking. Panspermia, literally "seeds everywhere" is a hypothesis that states basically, that spores and/or bacteria are cosmic travellers surviving the rigors of interplanetary travel, reaching habitable planets and therefore starting the development of life upon that planet.
This theory was first put forth over 125 years ago by Lord Kelvin, for whom the Kelvin temperature scale is named, although he believed that life(animals, plants, seed, etc) could be safely transplanted through space. Today we know that life can not survive the harsh elements of space without protection, but it was a beginning.
In 1908, Svante Arrhenius proposed the panspermia hypothesis, but stated that it was microscopic life such as bacteria that could travel aboard comets or asteroids. This was a bit easier to accept, but still mostly ignored.
In modern times, Sir Fred Hoyle and Chandra Wickramasinghe have been the loudest pro- ponents of panspermia by proclaiming that it was indeed possible that bacteria from the tails of comets could have seeded Earth and other planets. Their work was also ignored for the most part because no one believed any kind of life could survive travelling in the harsh environment of space. Then came the Mars meteorite.
IN 1996, David McKay and his colleagues announced that they had discovered fossilized microbacteria in a meteorite from Mars. The announcement sparked a great deal of controversy and debate and it even continues to this day whether the findings were conclusive of other life or not. However, further examination of other Martian meteorites have shown possible fossils of more normal sized bacteria and the discovery of other bacterial life in what was once believed to be inhospitable places on our own planet; such as Antarctica and the Earth's crust, does lend some credence to the possibility that just maybe this sort of thing can and does occur in the universe. Some microscopic lifeforms have been shown to survive cycles of freezing, dehydration, extreme heat, etc. Some scientists venture that this trait developed from surviving interplanetary travel. Only further research will reveal the truth. |