The discovery of a piece of space dust in our planet's atmosphere suggests that it is a remnant of the early solar system.-(Image credit: NASA via University of Tokyo)
A new study suggests that astrobiologists should investigate space dust and other exoplanetary debris to seek evidence of extraterrestrial life. According to the study's author, Tomonori Totani, an astronomy professor at the University of Tokyo, up to 100,000 dust particles carrying signs of life could be reaching Earth annually. This debris could originate from a life-harboring planet, propelled into space by a large asteroid impact, and carry preserved evidence of that life.
While the idea is similar to the panspermia hypothesis, Totani's paper delves into the data on this scenario. Fragments of planetary ejecta around one micrometer wide could host single-celled organisms and reach interstellar speeds. However, the distances involved reduce the chance of such ejecta reaching us, and numerous phenomena in space could destroy small objects.
Nevertheless, Totani's calculations suggest that 100,000 pieces of space dust containing preserved microbial life could reach Earth each year, some of which may be present in Antarctic ice or on the seafloor. The press release suggests that such specimens may be relatively easy to recover. Still, distinguishing extraterrestrial material from that of our solar system remains challenging, and the study concludes by urging scientists to explore the possibilities that this research may add to the search for life beyond our planet.
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