There have been questions about a mysterious ninth planet in our solar system for nearly a decade. Pluto was unseated as number nine in 2006. Now, a group of international researchers say they may ...

For nearly a decade, astronomers have been searching for a hypothetical giant planet that may lurk in the distant reaches of the solar system. We could be on the brink of discovering this new world, ...

An artist's illustration of a possible ninth planet in our solar system, hovering at the edge of our solar system. Neptune's orbit is shown as a bright ring around the Sun. Scientists in Taiwan ...

Traveling between planets is far more difficult than most people imagine. Even with modern rockets, journeys across the solar system take months, years, or even decades depending on planetary ...

For centuries, humans have gazed at the stars, trying to understand what lies beyond the familiar planets we know. From Mercury’s blazing orbit near the Sun to Neptune’s icy edge, our Solar System has ...

Illustration comparing the planets of the Solar System and the Sun on the same scale. The planets are shown to scale relative to each other but their distances are not. From left to right the bodies ...

The search for an unknown planet in our solar system has inspired astronomers for more than a century. Now, a recent study suggests a potential new candidate, which the paper’s authors have dubbed ...

WASHINGTON >> Scientists have identified an object about 435 miles wide inhabiting the frigid outer reaches of our solar system that might qualify as a dwarf planet, spotting it as it travels on a ...

There’s a bit of a paradox about our galaxy: it’s both jam-packed with stars and cavernously empty. The Milky Way is crowded in the sense that it holds hundreds of billions of stars, as well as ...

An exoplanetary system about 116 light-years from Earth could flip the script on how planets form, according to researchers who discovered it using telescopes from NASA and the European Space Agency, ...