Here's what's in our sun's deep freezer.

What can rocky planets orbiting in the outer parts of a solar system teach scientists about planetary formation and evolution? This is what a recent study published in Science hopes to address as a ...

NASA’s Hubble Space Telescope and James Webb Space Telescope have revealed that some of the smallest objects beyond Neptune ...

What new methods can be used to find long-period exoplanets, or exoplanets with orbits lasting from months to decades? This is what a recent study published in The Astronomical Journal hopes to ...

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 ...

IN THE dark reaches of the solar system lurk swarms of hidden worlds. Too small and too distant to reflect sunlight, they have remained under the cover of darkness for billions of years. But now the ...

Planetary scientists have long debated where the material that formed Earth comes from. Despite its location in the inner solar system, they consider it likely that 6–40% of this material must have ...

The monsters are multiplying. Just months after astronomers announced hints of a giant “Planet X” lurking beyond Pluto, a team in Spain says there may actually be two supersized planets hiding in the ...