If Brown’s hidden world is real, Rubin will almost certainly find it or strong indirect evidence that it exists. “In the ...

If there is some planet nine, or "Planet X" lurking out there, we have yet to find it. But there is some tentative evidence for it. As we have found more Pluto-like bodies known as Trans-Neptunian ...

Known as Planet Nine or Planet X, it is a hypothetical planet that has long been rumoured to exist in the outer solar system. Although "several claims to have found an extra planet have been made ...

A new paper discusses the possible existence of an unseen planet in the outer solar system, the so-called "Planet X" or ...

Like parents passing down their distinctive nose or eye color to their children, young planets were thought to be formed ...

But even including Arda/Earth, these planets only account for seven of the nine planets. As usual, Pluto was left out of the lineup, which just leaves Venus. However, Venus has a more involved ...

The Webb telescope has confirmed a controversial discovery made over 20 years ago with the Hubble Space Telescope.

What planet appears close to the moon? It depends on the night, but throughout the year each of the five closest planets will ...