Alien Hunt! Space dust could hold clues to extraterrestrial life


Devdiscourse News Desk | Tokyo | Updated: 28-03-2023 08:47 IST | Created: 27-03-2023 21:25 IST
Alien Hunt! Space dust could hold clues to extraterrestrial life
Representative Image. Credit: Pixabay
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When large celestial objects, such as comets or asteroids, are broken apart by enormous collisions, some amount of dust and other debris from the impacted bodies is ejected into space.

Theoretically, this material could contain direct or indirect signs of life from the host world and humans could detect it in the near future or even now, says Professor Tomonori Totani from the University of Tokyo's Department of Astronomy, who has proposed a way to search for alien life using this space dust ejected from terrestrial exoplanets.

"I propose we study well-preserved grains ejected from other worlds for potential signs of life. The search for life outside our solar system typically means a search for signs of communication, which would indicate intelligent life but precludes any pre-technological life. Or the search is for atmospheric signatures that might hint at life, but without direct confirmation, there could always be an explanation that does not require life. However, if there are signs of life in dust grains, not only could we be certain, but we could also find out soon," said Totani.

According to Prof. Totani, large asteroid strikes can release ground material into space. Some rocky material in this ejecta may contain microorganisms that are either recently deceased or fossilized. The size of the ejected material varies, and so does their behaviour in space. For instance, larger pieces might fall back or enter orbits around a local planet or star while some much smaller pieces may not contain signs of life. However, grains around 1 micrometer could contain a specimen of a single-celled organism and could potentially escape their solar system and reach another, such as ours.

Prof. Totani estimates that around 100,000 such grains could be landing on Earth every year, in places such as the Antarctic ice, or under the seafloor.

"Despite that, I calculate around 100,000 such grains could be landing on Earth every year. Given there are many unknowns involved, this estimate could be too high or too low, but the means to explore it already exist so it seems like a worthwhile pursuit," Totani concluded.

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