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 ...

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 ...

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 ...

Astronomers studying the interstellar comet known as 3I/ATLAS have detected a vast and unexpected X-ray halo extending roughly 250,000 miles around the object, a finding that is challenging ...

Astronomers have spotted an intriguing cluster of objects in the Kuiper belt, the enormous, donut-shaped region of icy objects beyond the orbit of Neptune. This latest “inner kernel” was identified by ...

The Kuiper belt, a disc of icy rocks on the outermost edges of the solar system, seems to have more structure than we thought. In 2011, researchers found a cluster of objects there on similar orbits ...

A new report says that Harvard astrophysicist Avi Loeb has found a 12th unexplained anomaly in the interstellar comet known as 3I/Atlas. This discovery has caught the attention of space enthusiasts ...

Comet C/2025 A6 (Lemmon) is this year’s brightest comet visible from Earth—an icy relic from the solar system’s origins that won’t return until the next millennium. Comet C/2025 A6 (Lemmon), captured ...

(NEXSTAR) — Skywatcher or not, you’ve likely heard of Halley’s comet. As popular as it is, however, seeing it may be a once-in-a-lifetime occurrence for some. The comet, often referred to as just ...

The comets A6 (Lemmon) and R2 (SWAN) are visitors from the chilly fringes of our solar system, and could even be visible at the same time. By Marina Koren If you like comets, this month is shaping up ...