Dust released from hypothetical eco-planets into the void between stars could carry traces of life. This idea is explored by researchers at the University of Tokyo.
The space separating stars is filled with a thin mix of gas and dust. This material drives the development of galaxies, seeds the birth of new star systems, and serves as a stage for countless chemical reactions that shape cosmic chemistry.
Tomonori Totani proposed that researchers should search for life’s fingerprints within this dust. He notes that when a habitable planet collides with another body, material from the surface can be blasted into space. This is a natural process in our solar system, with Martian meteorites regularly turning up on Earth. In such events, fragments as small as a micron could be expelled from a planetary system and drift into interstellar space. If life or chemical signatures exist in these grains, they might survive long enough to be detected in distant regions of the galaxy.
Totani also acknowledges that the odds of dust grains from other stars reaching our solar system are extremely small, given the vastness of the galaxy and the harsh conditions that can destroy delicate traces of life. Still, he suggests that roughly 100,000 such grains could descend to Earth each year under certain conditions. In theory, this material could accumulate within Antarctic ice or deep-sea sediments, though distinguishing extrasolar material from that produced in our own solar system remains a major challenge. Another practical approach involves sending dust collectors into space, a concept realized by the American Stardust mission, which has been operating since 1999. These collectors aim to capture samples for analysis, offering a potential window into the broader cosmos as seen from Earth. (University of Tokyo)