The small world was found during a search for the hypothetical Planet Nine, and astronomers say the next time it will reach ...

Our solar system’s origin story spans billions of years and involves clouds of gas, cosmic collisions, and planetary ...

The plains house the aptly named Very Large Array (VLA)—a radio telescope made of 27 different antennas, each of which looks ...

A distant, icy world has just been added to our solar system’s official roster, and its strange orbit might challenge one of ...

Today, it’s believed that Jupiter and Saturn, the largest planets, were the first to fully form, both within a few million ...

Pluto was reclassified as a dwarf planet in 2006. Our solar system may have a ninth planet after all, researchers say. The possibility that an additional planet may be hidden far into the solar ...

Our solar system may have a ninth planet after all, researchers say. The possibility that an additional planet may be hidden far into the solar system was touted more than a century ago. But ...

All of our solar system’s planets are lining up in the night sky at once this week. This extraordinary celestial event will see the sky scattered with seven visible planets in what is known as a ...

With Mercury joining the show, all seven ... striking line of planets across the night sky in January. This week Mercury joins the queue. Now every other world in our solar system will be visible ...

Sky watchers could witness a breathtaking celestial spectacle on February 28, with reports claiming that all the planets in our solar system will align. This event marks the final occurrence of an ...

When I was a kid, there were nine planets. Now we know of thousands! But that includes exoplanets, alien worlds that orbit alien suns. Only eight planets call our solar system home. Or there might ...