Jeffrey Andrews-Hanna, a planetary scientist at the University of Arizona, has been at the helm of a groundbreaking study. In these areas, the new research suggests surprising details about the South Pole-Aitken basin, the largest impact crater on the moon. This significant research, published in the journal Nature, sheds light on the moon’s tumultuous past and offers explanations for longstanding questions regarding the differences between the moon’s far and near sides.
The South Pole-Aitken basin stretches more than 2,000 kilometers (more than 1,200 miles) from north to south and 1,600 kilometers (1,000 miles) from east to west. Some 4.3 billion years ago, one of these asteroids the size of Mars smashed into the moon’s far side. The subsequent collision greatly defined the moon that we see today. The impact that created this vast crater occurred in a southward direction, resulting in distinctive geological features that continue to intrigue scientists.
Understanding the Formation and Characteristics
The South Pole-Aitken basin, the moon’s largest and oldest impact crater. It has a geological profile unlike any other on Earth… something that’s made it especially appealing to scientists. The basin’s most striking feature is its radioactive “KREEP-rich” blanket of ejecta on one side. This blanket artwork was produced using materials synthesized from xenon excavated from the lunar magma ocean. For one thing, scientists thought this ocean formed earlier in the moon’s history.
Andrews-Hanna’s study gives us a compelling view of the moon’s evolution during this time period. He proposes that beneath parts of the far side of the moon, a thin and patchy layer of magma ocean would have existed. Eventually, over the course of millions of years, the magma ocean cooled and solidified. This geologic process formed the crust and mantle, giving rise to the varied geology we have today.
This research is a major step in understanding how such massive impact events can gouge out such impact bodies, ranging from planetary moons to exoplanets. Andrews-Hanna makes comparisons between the South Pole-Aitken basin and other big impact sites, like the Hellas basin on Mars and the Sputnik basin on Pluto. He focuses on the common shaping processes that result from these side-swipe impacts. Such meaningful comparisons enable scientists to develop models that can be used to predict where geological features may exist on different celestial bodies.
Discrepancies Between Moon’s Far and Near Sides
One of the most intriguing aspects of Andrews-Hanna’s findings is their potential to explain why the moon’s far side is so dramatically different from its near side, which faces Earth. The crust on the far side was found to be considerably thicker than the near side. This geologic difference produces a rich diversity of morphology and a brilliant color contrast between the two types of surfaces.
According to the study, KREEP-rich materials found in the ejecta blanket may hold the key to understanding this disparity. These materials probably came from the magma ocean on the moon, which was a key process in developing the crust. The presence of KREEP-rich material is one of the indications that the far side was shaped by different geological processes. These erosional processes have greatly affected its structure and composition.
By taking a close look at these discrepancies, Andrews-Hanna hopes to answer some of the questions about how the moon formed and evolved. The research unlocks dynamic new paths for exploration into lunar geologic time and impact catastrophes. Our museum experience shows the need for understanding not just what occurred during large impacts but how those impacts influenced the geological processes and evolution that came after.
Implications for Future Research
Andrews-Hanna’s research has bigger implications for how we understand our own planetary science as well. Researching the South Pole-Aitken basin teaches us important lessons. These findings will inform upcoming crewed missions to the lunar surface and future missions deep into our solar system. By uncovering details about past geological processes, scientists can better assess how similar features might behave on other planets and moons in our solar system.
Together, this research underlines the importance and opportunity for further investigation and interpretation of lunar geological processes and history. Scientists have recently begun to explore the formation of impact basins extensively. Equipped with this information, they’re able to form a more complete picture of planetary evolution. The findings from Andrews-Hanna’s study serve as a reminder that even familiar celestial bodies like the moon can hold secrets waiting to be discovered.