No matter what part of the world you are on, you are constantly seeing only one side of the moon. Its other side is constantly inverted on the opposite side of our planet, and this distant, so-called The dark side is cut by the craters more than the part facing us.
The side near the moon, that is, facing us, is covered with vast plains of volcanic basalt, which are visible from here in the form of dark spots. The reason for this two-dimensional appearance remained a mystery – a puzzle that arose after the first spacecraft to orbit the moon in the 1960s. However, a new simulation may finally solve this puzzle of Apollo Khan.
After combining different characteristics, computer models support the notion that massive impact craters near the moon were at one time completely covered by lava flows. The differences are not only superficial, they go quite deep as they are reflected in the different geological compositions of the two sides of the moon.
Astronomers have long suspected that the near side of the moon was once covered with a sea of magma, which, after cooling, flattened the rocky landscape and formed the dark spots we see today. But, the cause of this volcanic activity remains a matter of controversy among scientists.
Such a difference can be explained by the massive crater at the Moon’s South Pole, called the South Pole-Aitken (SPA).
This pool is the result of one of the largest and most ancient collisions on the moon. As the simulations show, this collision, which occurred about 4.3 billion years ago, occurred at the exact time and exact place to cause changes on only one side of the moon’s mantle.
The enormous heat generated by the blow had to warm the upper part of the mantle to such a wide part on the near side; According to experts, this should have resulted in concentrations of potassium, rare earth elements, phosphorus and heat-producing elements, such as thorium.
At the moment, this is exactly the composition that scientists have found in rock samples brought from near the moon, especially in the Procellarum KREEP Terrane (PKT) – this is a vast region known for its anomalous composition.
“We have shown that during the formation of the South Pole-Aitken basin, in any possible environmental conditions, concentrations of these heat-generating elements were concentrated on the nearby side. “We think that’s what caused the mantle to melt, which created the lava flows we see on the surface today,” said Matt Jones, a planetary scientist at Brown University.
The remnants of the South Pole-Aitken collision have been falling from the sky for hundreds of millions of years.
In the simulations, the newest nearby volcanic plain was formed during an eruption 200 million years after the impact event. Moreover, the strongest moments of volcanic activity continued even after 700 million years after hitting the near side of the moon.
According to experts, the reason why this side of the moon had more response to the impact is twofold – heat-generating materials were concentrated at the site of the impact; And slight changes in gravity.
In each of the scenarios tested by the researchers, the upper part of the mantle in the southern hemisphere was heated and began to flow in the direction of the northern hemisphere, passing near the side of the moon.
Meanwhile, the top of the “dark side” mantle was too cold to distribute the same materials there in the same way.
Such a difference must have produced quite well the asymmetry that exists today between the two sides of the moon.
The emergence of the Procellarum KREEP Terrane region is indeed the most important unanswered question in lunar science. The impact of the South Pole-Aitken is one of the most important events in the history of the moon. “Our research brings together two things, and I think the results are really exciting,” said Matt Jones, a planetary scientist at Brown University.