The boundary of a solar system is not defined by planets, but by gravity. Beyond Pluto and the Kuiper Belt lies the Oort Cloud, extending up to a light year from the Sun and still considered part of ...

What lies beyond Pluto and the Kuiper Belt? Today we explore the Oort Cloud a vast, invisible shell of trillions of icy bodies that may stretch nearly two light-years from the Sun. Though never ...

Interstellar comet 3I/ATLAS streaks across the sky with a blue plasma tail, photographed from June Lake, California, on December 14, 2025. Dan Bartlett One of only three known interstellar objects ...

Comet 3I/ATLAS is a rare visitor passing briefly through our solar system. Here’s how to find it in the night sky—and what you’ll need to catch a glimpse. Interstellar comet 3I/ATLAS streaks across ...

3I/ATLAS has now made its closest approach to the sun and Earth and is now heading back out toward the outer solar system. When you purchase through links on our site, we may earn an affiliate ...

Astronomers have revealed new research showing that millions of new solar system objects are likely to be detected by a brand-new facility, which is expected to come online later this year.

Highlights from a cometary trio that captured our imaginations. When you purchase through links on our site, we may earn an affiliate commission. Here’s how it works. 2025 has seen stargazers look on ...