Have you heard? Earth has a second moon. Though this news isn’t exactly new—the fact was confirmed in 2021—it’s not widely known. This may be because the facts around our planet’s additional orbiter are a touch confusing.
Still, Kamoʻoalewa, Earth’s second moon, is real—and just another of the many things that make the Universe and our place in it so infinitely awesome. Here’s what you need to know.
What Exactly Is Kamoʻoalewa, aka Earth’s Second Moon?
Illustration: Addy Graham/University of ArizonaKamoʻoalewa is a lunar-like astral body that seems to be accompanying our planet in our astral cycles. The “moon” is more accurately defined as a quasi-satellite, a broad term for space stuff that orbits the sun at a close distance to our planet. The body is observable for a few weeks each April, and has an orbital pattern very similar to our own, with a year just a few hours longer than Earth’s
Earth’s mini-moon was first spotted in 2016 in Hawaii, hence its name, which either translates to “oscillating celestial fragment” or alludes to a chant that speaks of offspring, depending on who you ask.
As for exactly what it is, though, researchers are still speculating. The moon may be an asteroid or, perhaps more likely, a fragment of our own moon, broken off in an impact event. Regardless, Kamoʻoalewa is estimated to have been in orbit for about 500 years, with another 300 to go.
Does Earth Have Other ‘Moons?’
Photo: JPL-CALTECH/NASA via Science News ExploresThe Earth has a host of present and past moon-like co-orbiters, or quasi-satellites. Kamoʻoalewa most stable of the five known quasi-satellites of the Earth, some of which include 2020 PN1, 2020 PP1, and 2020 KZ2, and all of which travel a similar path.
But, as a “moon” is defined as a natural satellite of a planet, the answer is yes! As these celestial bodies are traveling with us on our space journey, deeming them moons is the least we can do.