What is the massive thing under the Moon’s surface?

A surprise on the far side of the Moon.

  • Scientists detect a gigantic, underground, metallic anomaly down a crater on the Moon.
  • "Whatever it is, wherever it came from," it looks to be billions of years old.
  • It's probably the remains of an asteroid that hit the Moon.

"Imagine taking a pile of metal five times larger than the Big Island of Hawaii and burying it underground. That's roughly how much unexpected mass we detected." That's Peter B. James of Baylor University talking about a gigantic anomaly found beneath the Moon's surface. He's the lead author of a study published in Geophysical Research Letters describing the odd find. There are a few theories about what it could be.

Mystery mass

Image source: CNSA/CLEP

China's Yutu-2 rover departs from the Chang'e-4 lander on the Moon's far side.

The thing sits beneath the Moon's South Pole-Aitken basin, believed to be the largest intact crater in our solar system. The oval-shaped feature is thought to be about 4 billion years old, and it's big: about 2,000 kilometers across at some points. Situated on the far side of the Moon, it can't be directly seen from Earth. Even so, James calls it, "one of the best natural laboratories for studying catastrophic impact events, an ancient process that shaped all of the rocky planets and moons we see today."

In studying the basin, James and his colleagues pored through data from NASA's Gravity Recovery and Interior Laboratory (GRAIL) mission to document changes in the strength of the Moon's gravity. "When we combined that with lunar topography data from the Lunar Reconnaissance Orbiter," says James, "we discovered the unexpectedly large amount of mass hundreds of miles underneath the South Pole-Aitken basin." He says "whatever it is, wherever it came from," it's pulling down the floor of the crater by more than half a mile.

So, erm, what is it?

Peter B. James.

Image source: Baylor University

Peter B. James.

The two most likely theories are that it's the iron-nickel core of a long-ago asteroid impact, or that it's a leftover clump of dense oxides from the cooling of the Moon's magma. Or, sure, a giant spaceship or hidden underground civilization, ahem.

James says, "We did the math and showed that a sufficiently dispersed core of the asteroid that made the impact could remain suspended in the Moon's mantle until the present day, rather than sinking to the Moon's core."

It's an intriguing find, and with ongoing international efforts to study the Moon's far side — such as China's Chang'e 4 mission — we look forward to further insights on this huge anomaly.

How to vastly improve your problem-solving workshops

To reach a breakthrough solution to any problem, it's necessary to first understand the underlying causes.

Videos
  • Companies often jump right into workshopping solutions to a problem before they truly understand the underlying source and "pain points" of the issue.
  • Deliberate Innovation CEO, Dan Seewald, advises companies to visualize and map out those unmet needs in order to discover a new path to a fresh solution. Only then should you move onto brainstorming and ideation techniques.
  • These important steps allow for more meaningful experimentation, as well as greater opportunity for learning and breakthroughs.
Keep reading Show less

Why Secular Humanism can do what Atheism can't.

Atheism doesn't offer much beyond non-belief, can Secular Humanism fill the gaps?

Photo by mauro mora on Unsplash
Culture & Religion
  • Atheism is increasingly popular, but the lack of an organized community around it can be problematic.
  • The decline in social capital once offered by religion can cause severe problems.
  • Secular Humanism can offer both community and meaning, but it has also attracted controversy.
Keep reading Show less

Is life after 75 worth living? This UPenn scholar doubts it.

What makes a life worth living as you grow older?

Culture & Religion
  • Dr. Ezekiel Emanuel revisits his essay on wanting to die at 75 years old.
  • The doctor believes that an old life filled with disability and lessened activity isn't worth living.
  • Activists believe his argument stinks of ageism, while advances in biohacking could render his point moot.
Keep reading Show less