No matter where you are on Earth, you only see one side of the moon. That’s because it is tidal locked, that is, only one side of it is always facing the Earth
One of the Moon’s longest-standing mysteries is why its near and far sides are so different. The nearside is known for its lunar mare while the far side is almost completely without large-scale mare features.
Now, according to a new study published in the journal Science Advances, these differences may have emerged from a colossal giant impact billions of years ago. The research shows how the impact that created the Moon’s the South Pole–Aitken (SPA) basin is linked to the stark contrast in composition and appearance between the two sides of the Moon.
Matt Jones, a Ph.D. candidate at Brown University and the study’s lead author, said, “We know that big impacts like the one that formed SPA would create a lot of heatThe question is how that heat affects the Moon’s interior dynamics. What we show is that under any plausible conditions at the time that SPA formed, it ends up concentrating these heat-producing elements on the nearside. We expect that this contributed to the mantle melting that produced the lava flows we see on the surface.”