In the pursuit of understanding life beyond Earth, a pioneering strategy emerges: harnessing solid grains expelled from exoplanets through asteroid impacts. As the search for extrasolar biosignatures gains momentum, the challenge lies in deciphering these signals remotely. This study introduces an alternative route: collecting minuscule grains, propelled from distant exoplanets in the Milky Way by asteroid impacts, and transporting them to our Solar System for analysis.
While scrutinizing exoplanet atmospheres for biosignatures remains intricate, this approach capitalizes on the prospect of discovering life remnants carried within ejected grains. Ideal for this purpose, grains measuring about 1 μm are targeted. Although uncertainties persist, projections suggest around 105 of these grains could reach Earth annually, potentially harboring traces of life from their original worlds.
Collecting these grains could be achieved through space-based detectors or by retrieving them from Antarctic ice or deep-sea sediments, contingent upon future technological advances. By charting this unconventional path, scientists strive to unearth clues to extraterrestrial life, unlocking cosmic mysteries through the microcosm of ejected grains.
