Meteorite samples are far from perfect surrogates for asteroids, though. They experience extreme pressures and lose a great deal of their bulk when falling through Earth’s atmosphere. Once they land, they pick up contaminants from the terrestrial environment that are hard to distinguish from native substances. Pristine samples from an asteroid might not only answer questions about the origins of life’s chirality but also offer clues about how water ended up on Earth. One hypothesis suggests that asteroids, which contain some water, may have also seeded it onto our home planet during collisions (Science 2014, DOI: 10.1126/science.1261952). [0]
[0] https://cen.acs.org/physical-chemistry/astrochemistry/tale-2...