This is an artist’s concept of excess left-hand aspartic acid created in asteroids and delivered to Earth via meteorite impacts. The line at the bottom is a chromatogram showing that left-hand aspartic acid (tall peak in the center, with diagram of left-hand aspartic acid molecule on top) was four times more abundant in the meteorite sample than right-hand aspartic acid (smaller peak to the left, with right-handed aspartic acid molecule on top).
Researchers analyzing meteorite fragments that fell on a frozen lake in Canada have developed an explanation for the origin of life’s handedness — why living things only use molecules with specific orientations. The work also gave the strongest evidence to date that liquid water inside an asteroid leads to a strong preference of left-handed over right-handed forms of some common protein amino acids in meteorites. The result makes the search for extraterrestrial life more challenging…
