This 8 minute animation realistically shows the major parts of the molecular machinery within cells: DNA coiling, replication, transcription, translation. Made by Drew Berry of The Walter And Eliza Hall Institute of Medical Research in Melbourne, Australia.
June 16, 2008
June 6, 2008
Scientists from the Cardiff Centre for Astrobiology collected particles from the stratosphere up to 41 km up using a specially designed and cleaned device attached to a balloon. They found hundreds of particles in their filters, among them living cells. Due to the nature of our atmosphere it is highly unlikely that any of those cells found their way up from the earth by themselves, implying that at least some must have come from somewhere else.
Link to the papers and more pictures.
Theories of panspermia are rapidly coming into vogue, with the possibility of the transfer of viable bacterial cells from one planetary abode to another being generally accepted as inevitable. The panspermia models of Hoyle and Wickramasinghe require the transfer of viable bacterial cells from interstellar dust to comets and back into interplanetary and interstellar space. In such a cycle a viable fraction of as little as 10-18 at the inception of a newly formed comet/planet system suffices for cometary panspermia to dominate over competing processes for the origin and transfer of life. The well-attested survival attributes of microbes under extreme conditions, which have recently been discovered, gives credence to the panspermia hypothesis. The prediction of the theory that comets bring microbes onto the Earth at the present time is testable if aseptic collections of stratospheric air above the tropopause can be obtained. We describe a recent collection of this kind and report microbiological analysis that shows the existence of viable cells at 41km, falling to Earth at the rate of a few tonnes per day over the entire globe. Some of these cells have been cultured in the laboratory and found to include microorganisms that are not too different from related species on the Earth. This is in fact what the Hoyle-Wickramasinghe theory predicts. The weight of evidence goes against the more conservative explanation that organisms are being lofted to the high atmosphere from the ground.
Life from Space