Key Takeaways:
- Scientists unearth a colossal structure beneath the Moon’s surface, weighing a staggering 2.18 billion billion kilograms and spanning over 300 kilometers in depth.
- This discovery was made possible through NASA’s Gravity Recovery and Interior Laboratory (GRAIL) mission, which discerns subtle shifts in the Moon’s gravitational field.
- Lead researcher Peter B. James likens the find to burying a metal heap five times larger than Hawaii’s Big Island underground, highlighting the unexpectedness of the mass.
- The anomaly is suspected to be remnants of the asteroid that created the Moon’s largest preserved crater, the South Pole-Aitken Basin, over 4 billion years ago.
- The basin’s unique properties make it an invaluable site for comprehending the Moon’s interior composition and unraveling its ancient history.
Our celestial neighbor, the Moon, has long captivated the imaginations of scientists and stargazers alike. Nestled on its far side lies the South Pole-Aitken Basin, one of the most extensive preserved craters in the Solar System. This enigmatic expanse has been a focal point for numerous investigations, drawing the attention of orbiters and even the Chinese lander Chang’e-4. In a groundbreaking revelation, planetary scientists have unearthed an extraordinary structure beneath its surface.
This newly discovered structure is a behemoth, with a weight equivalent to 2.18 billion billion kilograms and a depth spanning over 300 kilometers, a distance akin to the span from Los Angeles to San Diego. Lead author Peter B. James, hailing from Baylor University, aptly illustrated its magnitude by likening it to burying a metal heap five times the size of the Big Island of Hawaii beneath the Earth’s surface. “That’s roughly how much unexpected mass we detected,” James remarked, emphasizing the astonishing nature of the find.
The discovery owes its fruition to NASA’s Gravity Recovery and Interior Laboratory (GRAIL) mission, a venture designed to discern minuscule shifts in the Moon’s gravitational field. Through this mission, scientists can delve into the Moon’s internal composition with unprecedented precision. Astonishingly, the mass unveiled has the potential to weigh down the entire basin floor by almost a kilometer, exerting a pull equivalent to sinking half a mile into the Earth’s crust. Considering the crater spans roughly 2,500 kilometers in diameter, this revelation holds profound implications.
Further investigation led the team to combine data from GRAIL with lunar topography information gleaned from the Lunar Reconnaissance Orbiter. The amalgamation exposed the unexpectedly colossal mass lurking hundreds of miles beneath the South Pole-Aitken basin. James posited, “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.”
To comprehend this anomaly, the team turned to advanced computer simulations. Two primary hypotheses emerged. First, it’s plausible that when the asteroid struck over 4 billion years ago, it became ensconced in the lunar mantle, defying expectations of a coreward descent. Alternatively, the Moon’s solidification may have led to the aggregation of dense oxides, a consequence of the cooling and settling of the ancient magma ocean.
The allure of the South Pole-Aitken Basin for space agencies worldwide stems from its unique attributes. It serves as an unrivaled laboratory for probing both the Moon’s interior composition and its storied past. Moreover, it stands as a vivid testament to the cataclysmic aftermath of a colossal impact on the surface of a rocky celestial body, offering profound insights into planetary evolution. The discovery of this colossal subsurface structure not only sheds light on the Moon’s complex history but also sparks a new era of lunar exploration and inquiry.
