What does Earth's moon and several of the larger asteroids hovering around our solar system have in common? Well, according to NASA, they've both been blasted under a bombardment of asteroids in the past.
NASA scientists based at their Lunar Science Institute base in Moffett Field, Calif., have discovered that the moon and the giant Vesta asteroid-along with other large asteroids near Earth's solar system-were hit with high-speed projectiles in outer space some four billion years ago during what are described as an "intense" period of impacts, as the journal Nature Geoscience notes.
"This cataclysm is thought to have affected the entire inner Solar System and has been constrained by the radiometric dating of lunar samples," the report states.
That unexpected discovery provides a link between Vesta and the moon, while providing a new way to study the early bombardment history of terrestrial planets.
"It's always intriguing when interdisciplinary research changes the way we understand the history of our solar system," Yvonne Pendleton, NLSI director said according to Times of India. "Although the Moon is located far from Vesta, which is in the main asteroid belt between the orbits of Mars and Jupiter, they seem to share some of the same bombardment history."
The findings support a theory in a paper written by G. Jeffrey Taylor of the Hawaii Institute of Geophysics and Planetology that Jupiter, Saturn, Uranus and Neptune shifted orbits billions of years ago to their current positions. The shift triggered a "lunar cataclysm" which resulted in a hail of asteroids bombarding the entire solar system.
In addition, the research provided new insight on the start and length of time that the cataclysm lasted while showing that it affected more regions than just the inner system planets.
Scientists examined lunar samples brought back by Apollo astronauts, in addition to meteors that landed in the main asteroid belt and determined that large asteroids had likely been hit with the same bombardment that the inner planet and the moon were struck by once.
As JPL.com notes, howardite and eucrite meteorites, especially, were used to study the Vesta asteroid. Researchers linked the two sets of data and found that the same hail of space projectiles that left craters on the moon had his Vesta, leaving similar impact ages.
"It appears that the asteroidal meteorites show signs of the asteroid belt losing a lot of mass four billion years ago, with the escaped mass beating up on both the surviving main belt asteroids and the moon at high speeds" said. lead author Simone Marchi, who has a joint appointment between two of NASA's Lunar Science Institutes. "Our research not only supports the current theory, but it takes it to the next level of understanding."