MADRID, March 30
A University of Tokyo astronomy professor proposes to identify and study grains of space dust ejected from other worlds in search of signs of alien life.
After massive collisions, such as asteroid impacts, a certain amount of material from the impacting world can be ejected into space. This material can travel great distances and over long periods of time.
In theory, these materials could contain direct or indirect signs of a host world, such as fossilized microorganisms. And this material could be detected by humans in the near future, or even now, says Tomonori Totani in a study published on arXiv.
“I propose that we study well-preserved grains ejected from other worlds for possible signs of life,” Totani said in a statement. “The search for life outside our solar system generally means the search for communication signals that indicate intelligent life but exclude all pre-technological life. Or it is the search for atmospheric signatures that may hint at life, but without direct confirmation nothing could be done. It is always an explanation that does not require life. But if there are signs of life in the dust of the grains, we can find them not only faithfully, but also quickly.
The main idea is that large asteroid impacts could throw terrestrial material into space. There is a possibility that recently deceased microorganisms, or even fossils, may be contained in some of the rocky material in this ejecta.
This material will vary greatly in size, with pieces of different sizes behaving differently once in space. Some of the larger pieces may recur or enter permanent orbits around a planet or local star. And some much smaller pieces may be too small to contain verifiable evidence of life. And grains in the region of 1 micrometer (thousandth of a millimeter) could not only receive a sample of single-celled organisms, they could also completely escape their solar host and, under the right circumstances, perhaps even venture into the ocean. ., our
HUNDREDS OF THOUSANDS OF THIS TYPE REACH EARTH EVERY YEAR
“My website explores this idea using available data on different aspects of this scenario,” Totani said. “The distances and times involved can be enormous, and both reduce the chance that any ejected signs of life from another world containing them can reach us. Add to that the number of phenomena in space that can destroy small objects due to heat or radiation; the chances are also lower, although I estimate about 100,000 such grains could be found on Earth every year. Since there are many unknowns involved, this estimate could be too high or too high. It seems to be worth the effort.
Such grains already exist on Earth, and are preserved in abundance in places such as Antarctic ice or under the sea floor. Space dust in these areas could easily be recovered, but distinguishing extrasolar material from material originating in our solar world remains complex. However, if the research extends to space itself, there are already missions that capture dust in a vacuum using ultraviolet materials called aerogels.
