Add Yahoo as a preferred source to see more of our stories on Google. An illustration showing Planet Nine, a hypothetical, undiscovered planet in our solar system. New research now suggests the ...

For the first time since 2008, two new planets are being added to one of northern Maine's most famous — and scientifically accurate — roadside attractions. Dwarf planets Haumea and Makemake are the ...

A new study has proposed the existence of Planet Y, an alternative Planet Nine candidate that is smaller and closer to Earth than the hypothetical Planet X, which astronomers have been hunting for ...

Pluto has been added to the University of Arizona’s scale-model walking tour of the solar system, but will that be enough to mend the dwarf planet’s broken heart? Not likely, according to a recent ...