Astronomers have discovered fresh evidence suggesting the possible existence of an unseen planet in the far reaches of our solar system.

A new University of Michigan study offers one of the most detailed pictures so far of how violent sun storms spread across ...

While Planet Y has been not yet been directly observed, unexpected inclinations found in the orbits of roughly 50 distant ...

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 ...

SpaceX is preparing to launch three spacecraft on a first-of-its-kind mission to study the sun's influence throughout the solar system, from Earth's atmosphere to the edge of interstellar space. A ...