Scientists have discovered traces of an ancient collision with a protoplanet on the Moon. The study was published in the journal Nature, briefly reported by the EurekAlert!
The collision of the moon with a protoplanet or asteroid, according to scientists, occurred 3.8 billion years ago. In diameter, the celestial body reached 250-300 kilometers and, probably, belonged to class E objects in the asteroid belt between the orbits of Mars and Jupiter.
Protoplanet debris trajectories
Image: Peter Schultz
The projectile under experimental conditions (top) and simulation results (bottom)
Promotional video:
Image: Peter Schultz
Scientists came to their conclusions by analyzing possible scenarios for the formation of the geology of the Sea of Rains on the Moon, which includes an impact crater, as well as primary (emanating from the crater) and secondary ditches. The diameter of the territory (including the crater and ditches) reaches 1250 kilometers.
Geophysicists, using a special cannon that fired at the material at different angles, conducted laboratory experiments that showed that secondary ditches appeared after the fall of asteroid particles that had previously bounced off the surface of the Moon.
Previous estimates by scientists suggested that the diameter of the colliding object with the Moon reached 80 kilometers. The new study made it possible to clarify the size and mass of the celestial body. Geophysicists believe that, probably, in the early stages of the development of the solar system, the vicinity of Venus, Earth and Mars contained many similar protoplanets (or large asteroids).