Is there a massive undiscovered planet on the outer reaches of the solar system? The idea has been around since before the ...

International astronomers have for the first time witnessed the birth of a planetary system beyond Earth's sun that could one ...

Decades ago, a renegade physicist suggested that gravity isn't so much a force as just a byproduct of the universe's tendency ...

NASA scientists have discovered an electric field encompassing Earth’s atmosphere that is as "fundamental" as gravity -- and could even give clues about possible life on other planets.

"For the first time, we have identified the earliest moment when planet formation is initiated around a star other than our ...

A massive doomed exoplanet on a death spiral toward its parent star has three possible catastrophic fates. A massive planet ...

Our solar system officially houses eight planets, but some scientists say there could be a ninth. And that’s not just Pluto aficionados – evidence suggests a huge undiscovered world lurks on ...

Small but rowdy space rocks pushing and jostling one another may have created the unusual orbits some astronomers cite as the signature of the hypothesized "Planet Nine," a new study suggests.

Self-gravity – the gravitational force that holds sufficiently massive objects together – allows gas planets to maintain their form in the vacuum of space. Multiple lines of evidence show gas ...

There is less gravity in space than there is here on Earth, which could be one of many challenges for the long-term viability (or, at the least, convenience) of space habitats for future galactic ...

NASA scientists have discovered an electric field encompassing Earth’s atmosphere that is as “fundamental” as gravity — and could even give clues about possible life on other planets. A ...