The number of planets that orbit the sun depends on what you mean by “planet,” and that’s not so easy to define ...

A U.S. scientist searching for a civilization across 7 Earth clones circling the red dwarf star TRAPPIST-1 says its own alien ...

An object eight times the mass of Jupiter may have swooped around the sun, coming superclose to Mars' present-day orbit ...

A new study claims it is possible an "alien visitor" could have warped our solar system during its earliest years.

Where is our solar system in the vast assemblage of celestial objects in this island Universe we call the Milky Way? To answer that question, we can begin with the beautiful configuration of stars we ...

A trio of astronomers from the University of Tokyo and Niigata University have found what they describe as "peculiar embedded ...

The Gaia mission, launched by the European Space Agency, has completed a decade of groundbreaking astronomical observations, collecting over three trillion data points on two billion stars and ...

At just over 20,000 mph, experts say they're the fastest of their kind on any known planet. Find out more here.

However, it is now considered a dwarf planet instead. The universe has billions of galaxies, and our solar system is in the Milky Way Galaxy. The Milky Way contains at least 100 billion other ...

An exoplanet is a planet outside our solar system that usually orbits a star in our galaxy. More than 7,000 have been found ...

Ever since Isaac Newton famously talked about gravity, its dominance as a force in our solar system has been well known. It's ...