Planetary systems such as our solar system take hundreds of millions of years to evolve. Since humanity has only existed for a sliver of that time, astronomers have only observed planetary systems at ...

A possible cousin of Pluto seems to be circling the far reaches of the solar system. The dwarf planet candidate 2017 OF201 travels in a superwide orbit, with the sun relatively near one end of its ...

Sign up for CNN’s Wonder Theory science newsletter. Explore the universe with news on fascinating discoveries, scientific advancements and more. Astronomers have ...