Siraj’s Planet Y search started about a year ago when he was trying to find out whether the shape of the Kuiper Belt is flat.

A new study has proposed the existence of Planet Y, an alternative Planet Nine candidate that is smaller and closer to Earth ...

'Results ... are generally consistent with other null searches for Planet 9.' When you purchase through links on our site, we may earn an affiliate commission. Here ...

Scientists think there may be a ninth planet hiding in the distant reaches of the solar system — and a new telescope could finally prove its existence. | Credit: Nicholas Forder for Live Science Deep ...

In the continued search for the hypothetical ninth planet in our Solar System, Michael Brown, the CalTech astronomer who led the demotion of Pluto to a dwarf planet in 2006, has co-written a new study ...

Astronomers have long been on the hunt for "Planet Nine," a hypothetical planet that lies within our solar system just beyond Neptune. Scientific evidence has alternately pointed to and against the ...

When considering where to look for extraterrestrial life, astronomers have mostly stuck with what’s familiar. The best candidates for habitable planets are considered the ones most like Earth: small, ...

Comets and meteorites contain clues to our solar system’s earliest days. But some of the findings are puzzle pieces that don’t seem to fit well together. A new set of theoretical models from ...

Astronomers have been scouring the outer solar system for signs of a hypothetical ninth planet for almost a decade, without success. However, we may finally be on the cusp of finding it, experts say.