The Curious Case of Earth's 'Second Moon': A Rocket's Unexpected Return

Remember that fleeting moment, not so long ago, when the internet, and indeed, some astronomers, buzzed with the tantalizing possibility of Earth having gained a new moon? It was an exciting thought, wasn't it? The idea of a fresh celestial companion, however small, gracing our skies. But honestly, the universe, you see, often delights in a good prank, and this particular story, while fascinating, turned out to be less about a natural cosmic acquisition and more about a very old piece of our own space history making a rather dramatic, if brief, comeback.

The object in question, christened '2020 SO,' first caught the eye of astronomers back in September 2020. Initially, it looked just like any other asteroid – a small, rocky body that appeared to be gravitationally bound to our planet, briefly orbiting us. A 'mini-moon,' you could say, temporarily captured by Earth's pull. And for a spell, people wondered, talked, even dreamt a little about this new addition to our cosmic neighborhood.

But the story took a delightful, somewhat humbling, turn. NASA's keen-eyed experts at the Center for Near-Earth Object Studies (CNEOS) quickly got to work. They ran the numbers, crunched the trajectories, and then, quite definitively, dropped the cosmic mic: 2020 SO wasn't some primordial space rock. Not at all. In truth, it was a discarded Centaur rocket booster, a piece of space junk from 1966, belonging to the ill-fated Surveyor 2 mission.

A rocket booster from the 60s! Can you imagine? This metallic relic, having spent decades in a quiet solar orbit, just decided, for once, to swing back our way, getting temporarily snagged by Earth's gravity. It orbited us, like a dutiful, albeit artificial, moon from October 2020 until March 2021. Then, with a subtle shift in its trajectory, it politely detached itself, embarking once more on its solo journey around the sun. A truly temporary satellite, a bit of cosmic litter playing dress-up as a natural wonder.

This isn't to say Earth never has temporary mini-moons of a natural kind. We do, actually. Tiny asteroids, like 2006 RH120 or 2020 CD3, occasionally get caught in our gravitational embrace for a few months or even years before breaking free. These are genuine celestial wanderers, small rocks that momentarily become our satellites. But 2020 SO? That was different. That was us, looking at our own past, accidentally mistaking it for a brand new star (or, well, a moon).

It’s a peculiar thought, isn't it, that our own man-made creations can mimic natural phenomena in such an uncanny way? It serves as a gentle reminder, perhaps, of the sheer volume of material we've sent beyond our atmosphere—and how sometimes, it just might decide to pay us an unexpected, albeit temporary, visit. So, while Earth didn't gain a second natural moon, we certainly had a fascinating, if artificial, one for a brief, memorable stretch. And that, you might argue, is a story almost as good as the real thing.