The solar system formed about 4.6 billion years ago from a giant rotating cloud of gas and dust known as the solar nebula. Gravity caused the nebula to collapse in on itself, forming a dense, hot ...

In 2017, NASA discovered and later confirmed the first interstellar object to enter our Solar System. It wasn’t aliens. But artist impressions of the object (called ‘Oumuamua, the Hawaiian ...

Our solar system used to have nine planets. Astronomer Mike Brown, also known as “the man who killed Pluto,” said he got hate mail from kids and obscene calls at 3 a.m. for years after his ...