» Top New Releases in Books
Loading the page...
As a rule, you can safely assume that moons and asteroids will all orbit a planet in the same direction. If they didn’t, interactions with their host would likely send them flying off course. However, it’s now clear that there are exceptions to this rule: researchers have discovered that an asteroid is circling Jupiter in the opposite direction of all planets in the Solar System. These backwards-orbiting rocks are rare anywhere in the system (they represent just 0.01 percent of known asteroids), but this is the very first time one has been caught spinning around a planet. How is it sticking around, then?
In a sense, it’s a matter of luck. The asteroid travels on alternating sides of Jupiter, with one pass reeling it in while another pushes it outward — it’s in just the right trajectory to maintain a yin-yang balance. This is a stable orbit, too, as scientists estimate that the asteroid has been locked to Jupiter’s orbit for about 1 million years.
The finding isn’t completely shocking given the scale of the cosmos (something like this was bound to crop up), but it’s still important. It could help shed new light on how orbits work, and it’s a friendly reminder that space doesn’t always conform to expectations.