The trans-Neptunian object nicknamed Ammonite moves across the sky over several hours in May 2023. Its diameter is estimated to be between about 135 and 235 miles. NAOJ / ASIAA Astronomers have just ...

Low-Earth orbit is more crowded—and fragile—than it looks. Satellites constantly weave past each other, burning fuel and ...

The search for an unknown planet in our solar system has inspired astronomers for more than a century. Now, a recent study suggests a potential new candidate, which the paper’s authors have dubbed ...