Recently Discovered Asteroid Is Still In Geologic Diaper

Trust me, that headline makes sense in the end.

Back in November 2023, the Lucy space probe passed the asteroid 152830 Dinkinesh, a main-belt asteroid about a kilometer in diameter. During this close fly-by, Lucy discovered that Dinkinesh was actually a binary asteroid, as it had a small companion moon (about 200 meters in diameter). This moon was named Selam; its namesake is a young Australopithecus afarensis individual discovered about 25 years ago. Australopithecus afarensis, if you're not familiar, was an early homidid species, with the most famous example being ... Lucy, the space probe's namesake, who lived 3.2 million years ago. 

Keep that number in mind for a moment as we get back to Selam. The asteroid, not the ancient hominid.

Naturally, astronomers performed all sorts of research on Selam, and recently made a rather interesting discovery, based on the moon's orbit: Selam is young. It's a veritable infant, in fact, coming in at just 2 to 3 million years old. Now, that's obviously pretty old by normal human standards, but compared to the age of the solar system? That's nothing. Not only that, the asteroid is actually younger than the namesake of the space probe that discovered it. Pretty rare for a celestial object we've visited to be younger than something tangible in human history, but here we have it.

Also, the researchers calculated Selam's age using something called a tidal-BYORP equilibrium equation, and yes, the joke here is that BYORP is a funny-sounding acronym. Look, not everything can be high-brow and informative. Sometimes you just have to appreciate BYORP and leave it at that.