The Moon's South Pole-Aitken basin is the largest crater in the solar system. It was formed when an asteroid crashed into the lunar surface a long time ago، as the Technical Times said.
In a new study، scientists suggested that the remains of that asteroid are still buried underneath the ancient crater.
Mystery Of The South Pole-Aitken Basin While analyzing the data collected during NASA's Gravity Recovery and Interior Laboratory، or GRAIL، mission and the Lunar Reconnaissance Orbiter، a team of researchers from Baylor University noticed an anomaly between the surface topography and the gravitational tug of the moon.
"When we combined that with lunar topography data from the Lunar Reconnaissance Orbiter، we discovered the unexpectedly large amount of mass hundreds of miles underneath the South Pole-Aitken basin،" explained Peter B. James، an assistant professor of planetary geophysics and the lead author of the study. "One of the explanations of this extra mass is that the metal from the asteroid that formed this crater is still embedded in the Moon's mantle."
The South Pole-Aitken basin، as its name suggests، is located near the lunar south pole. It is oval-shaped and measures about 2،000 kilometers. Scientists believe that the crater was formed 4 billion years ago.
Remains Of A Massive Asteroid Whatever the mass is، it is weighing the basin floor downward by more than half a mile، the researchers shared. They tried computer simulations of large asteroid impacts and found that under the right conditions، pieces of an iron-nickel core might have been dispersed into the upper mantle.
"We did the math and showed that a sufficiently dispersed core of the asteroid that made the impact could remain suspended in the Moon's mantle until the present day، rather than sinking to the Moon's core،" James stated.
Another possible explanation for the anomaly is a concentration of oxides in the area. Oxides might have formed when the Moon's ancient magma ocean cooled and solidified.