We already know that more than one object can share the same orbit; Jupiter has a collection of 120,000 asteroids following its same path around the Sun, for example. Earth has one, too. But although it’s theoretically possible, astronomers have never discovered two whole planets sharing the same orbit around a star before.
https://www.inverse.com/science/astronomers-discover-cosmic-unicorn-two-planets-on-the-same-orbit
Hmm…the language here is a bit misleading. The two objects are technically not both “planets.”
The article comments later on that the object in the dotted line circle is “a cloud of debris about twice the mass of our Moon trailing a bit behind the innermost gas giant” in one of its LaGrange points (where “Trojan” asteroids follow gas giants such as Jupiter and Saturn). So it’s way too early to say that “two” planets formed in the same orbit.
Still, this is the first time that astronomers have spotted two such objects this close to one another in the same orbit. Who knows if both will remain viable (the debris cloud could become partly or mostly absorbed by the gas giant with the rest either being expelled or thrust into separate orbits).
So why is this called a “cosmic unicorn”?
Apparently because although such Trojans “are allowed to exist by theory, but no one has ever detected them.”
Um. OK.
So, like, totally NOT at all like this? Kind of a bummer, really…
