A young star called V1298 Tau is giving astronomers a front-row seat to the birth of the galaxy’s most common planets. Four ...

The International Astronomical Union defines a planet as a celestial body that orbits the sun, is massive enough that gravity has forced it into a spherical shape, and has cleared away other objects ...

A new study has proposed the existence of Planet Y, an alternative Planet Nine candidate that is smaller and closer to Earth than the hypothetical Planet X, which astronomers have been hunting for ...

If the object really is Planet Nine, it would be larger than Neptune and exist 700 times further from the sun than Earth. When you purchase through links on our site, we may earn an affiliate ...

When I was a kid, there were nine planets. Now we know of thousands! But that includes exoplanets, alien worlds that orbit alien suns. Only eight planets call our solar system home. Or there might ...