A planetary system 116 light-years from Earth has a peculiar pattern. It could flip the script on how planets form, ...

Six planets will briefly share the twilight sky this month - but the conditions have to be just right.

PRAGUE, Czech Republic - Astronomers are proposing to rewrite the textbooks to say that our solar system has 12 planets rather than the nine memorized by generations of schoolchildren. Much-maligned ...

It is a question that feels like it should have a straightforward answer: how many planets are there in our solar system? Since Pluto was relegated back down to dwarf planet status, almost everyone ...