The “Man in the Moon,” a flat 1,800-mile-wide section of the moon, was most likely caused by an asteroid the size of Austria colliding with the moon, according to Japanese researchers.
Scientists working at the National Institute of Advanced Industrial Science and Technology believe that the Procellarum basin on the moon (the dark spot seen from Earth) that is frequently called a “man in the moon” is the remnants of this asteroid’s impact crater, reports UPI.
Researchers have studied how minerals in the area were distributed using mapping data obtained by the Japanese moon exploration orbiters.
One mineral they found is low-calcium pyroxene, which was likely generated when rock melted under the head of an impact, then concentrated in a near-circle around the Moon’s Procellarum basin. This caused them to believe that an asteroid the size of Austria (more than 180 miles in diameter) collided with the moon about 3.9 billion years ago.
Yahoo! News notes that the study, which was published in the British journal Nature Geoscience, says:
“The nearside and farside of the Moon are compositionally distinct. The detection of low-calcium pyroxene around large impact basins suggests that the huge Procellarum basin on the nearside may be an ancient impact structure and a relic scar of the violent collision that produced the lunar dichotomy.”
Junichi Watanabe, who is a professor of astronomy at the National Astronomical Observatory of Japan, stated, “The latest study explains why the moon’s two sides are so different. It helps unravel the mystery of the moon’s history.”
So, next time you look at the moon, try to spot the “Man in the Moon,” where an asteroid struck the celestial body almost 3.9 billion years ago.