The Moon has a hitchhiker.  Excerpt:

A large mass of unknown material has been discovered on the largest crater on the Moon and scientists aren’t sure what it is.

According to an April 2019 study published in the journal Geophysical Research Letters, the researchers believe the mass could contain metal from an asteroid that crashed into the celestial satellite, which resulted in the aforementioned crater, known as the Lunar South Pole-Aitken basin.

“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,” lead author Dr. Peter James, assistant professor of planetary geophysics at Baylor University, said in a statement.

At roughly 1,550 miles in diameter, the Lunar South Pole-Aitken basin stretches across approximately one-fourth of the Moon, according to NASA. The Moon’s circumference is roughly 11,000 kilometers.

Note:  The Moon isn’t a celestial satellite; it’s a planetary satellite.

Be that as it may, this is kind of cool.  It’s another little (well, actually it’s pretty big) piece of evidence on what a cluttered place our solar system is, and a reminder that every once in a while some big chunk of nickel/iron and silicates will come along and give one or another of the planets a good whack.

One of those whacks did in the non-avian dinosaurs.  Another one like that would sure cause us all sorts of headaches – of course, we might get lucky and have one land on Congress, which would make all of our liberties and property a bit more secure.

But back to the Moon.  According to the linked article, there is a good-sized metallic mass under Lunar South Pole-Aitken Basin, and I have a sneaking suspicion that it’s only a matter of time before the cranks come out, claiming that it’s a secret moon base for Nazis, or Confederates, or giant robots, or something equally silly.

NASA has been talking about establishing a permanent base on the moon.  If the remains of this long-gone asteroid aren’t buried too deeply, that may well be a great resource – as long as someone else hasn’t gotten there first.