An evaporating cloud may have shaped the once-chaotic orbits of the planets in our solar system.
Helium-3 released at Earth’s surface contains tales from the deep planet and the deep past.
At 85 miles in diameter, the comet is twice as large as the previous record holder—and it’s headed toward the Sun.
The luminous moment that a dead star swallows the torn-up remains of its planetary bodies has been witnessed for the first time.
The discovery of hundreds of new objects in the outer solar system confirms weird gravitational effects that could be caused by “Planet Nine.”
Stars show chemical traces of past "planetary ingestion" that can be used to search for Earth-like planets.
A radioactive isotope profoundly affected the origin and evolution of our solar system. Now, scientists have spotted it in a system of budding stars.
Voyager 1 has likely made the first continuous measurement of the density of matter in interstellar space.
Scientists have discovered a “hellish” new planet that is hotter than molten lava.
No other known object has characteristics similar to EC 002, an ancient meteorite found in an Algerian dune sea last year.