Uranus and Neptune are the third- and fourth-largest planets in our solar system, each about half the size of Saturn, or four times the size of Earth. But they orbit the sun at such extreme distances ...

Retrograde motion, typically observed in outer planets, is an apparent westward movement resulting from Earth's faster orbital speed overtaking those planets. This apparent reversal of direction is ...

More planets are changing directions. First, Mercury circled retrograde. This week, Mars is reversing course and Neptune starts spinning forward again. Going retrograde and stationing direct are the ...

There are a lot of moving parts to the Universe, as nothing exists in isolation. There are literally trillions of large masses in our Solar System, all orbiting around the galactic center on ...

They’re hot, they’re huge and they move the wrong way. In the rapidly growing catalog of planets found outside the solar system, about a dozen Jupiter-sized ones tightly circle their stars in the ...

The Atacama Large Millimeter/submillimeter Array (ALMA) has captured the motion of spirals of dust around a young star and shown that the winding motion of the spiral pattern is conducive to planet ...

When you purchase through links on our site, we may earn an affiliate commission. Here’s how it works. Paul M. Sutter is an astrophysicist at SUNY Stony Brook and the Flatiron Institute, host of "Ask ...