An international team of astronomers has discovered a distant planetary system that challenges long-standing theories of how ...

It would be understandable if you stopped thinking as much about Pluto after it was “demoted” from being considered one of the nine planets sharing the Earth’s solar system to being classified as a ...

One of the longest stellar dimming events ever observed was likely caused by the gigantic saucer-like rings of either an unseen brown dwarf or "super-Jupiter" blocking its host star's light, ...

Since the 1990s, scientists have discovered approximately 6,100 planets outside our solar system, called exoplanets.

Since Pluto remains in the sun’s orbit, it should be considered a planet due to the fact that it is still a part of the solar system. And since Pluto is still hanging on at the end of the system, it ...

Scientists have identified a rocky outer planet in a system where a gas giant was expected. The discovery challenges ...

According to these calculations, Earth's total lifespan will be about 9.5 billion years.

We classified Pluto before really understanding it—just like we reduce people to job titles or put names on relationships ...

Typically, from what astronomers have gathered thus far, star systems follow a tidy logic: small, rocky worlds huddle close to the warmth of their star, while massive gas giants bloat up in the colder ...

Astronomers have uncovered a distant planetary system that flips a long-standing rule of planet formation on its head. Around the small red dwarf star LHS 1903, scientists expected to find rocky ...

Mercury is the smallest planet in our solar system. Explore its size, extreme temperatures, core structure, and comparison with Pluto.

WASHINGTON — Astronomers have observed a planetary system that challenges current planet formation theories, with a rocky planet that formed beyond the orbits of its gaseous neighbors, possibly after ...