The far side of the Moon, which we can never see from Earth, looks different.
The near side, with which we are so familiar, appears darker in places, the result of extensive ancient lava flows, while the far side is cratered but not flowing.
Why the two sides of the moon are so different has puzzled astronaut scientists for a long time. However, a study published last week in the journal Science Advances provided a new explanation for this lunar mystery.
Researchers at Brown University have studied the largest impact crater on the Moon, known as the South Pole-Aitken Basin (or SPA). About 1,615 miles (2,600 kilometers) wide and five miles deep, it was formed by a massive cosmic object that crashed into the Moon – possibly a wayward dwarf planet – during the formation of the solar system.
According to the statement, the researchers found that the collision that formed the pool must have created a massive plume of heat that spread through the moon’s interior. This plume was supposed to carry certain materials to the near side of the Moon, fueling the volcanism that created the volcanic plains.
“We know that big hits like the one that formed SPA will generate a lot of heat,” said Matt Jones, a Brown University doctoral student and lead author of the study.
“The question is how this heat affects the internal dynamics of the Moon. We show that under any possible conditions at the time the SPA was formed, it would eventually concentrate these heat-producing elements on the near side.
“We expect that this contributed to the melting of the mantle, which created the lava flows that we see on the surface.”
The volcanic plains on the near side of the Moon are home to a group of elements, including potassium, rare earths, phosphorus, and others known as Procellarum KREEP terrane (PKT), that are rare elsewhere on the Moon.
The researchers ran computer simulations of how the heat generated by the giant impact would change the heat transfer pattern in the lunar interior and how this might redistribute the KREEP material in the lunar mantle.
According to their model, the KREEP material would have to slide over the heat wave emanating from the impact zone “like a surfer”, whether the impact was a direct hit or just hit the moon. As the thermal plume spread under the lunar crust, this material was eventually delivered to the near side.
“How the PKT formed is perhaps the most important open question in lunar science,” Jones said.
“And the Aitken South Pole impact is one of the most significant events in the history of the moon. This work brings together
