The catastrophic collision that forged the moon, and marked one of the most consequential events in Earth's early history, may have been triggered not by a distant interloper, but by a sibling world ...

A rare meteorite discovered in the Sahara Desert proves that our solar system almost had at least one extra planet. In a ...

Astronomers are closing in on one of the most tantalizing possibilities in planetary science, evidence that a previously unknown world may be lurking in the outer reaches of the solar system. The ...

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 ...

NASA is inviting the public to join 36 citizen science projects. Volunteers can help with discoveries from asteroids to Martian clouds. To join, email do-nasa-science-join@lists.nasa.gov with ...

About 4.6 billion years ago, a celestial cloud collapsed, paving the way for our solar system to form. Then, a nebula with strong gravitational pull took shape, kick-starting the birth of the sun. But ...

The official number of exoplanets—planets outside our solar system—tracked by NASA has reached 6,000. Confirmed planets are added to the count on a rolling basis by scientists from around the world, ...

Our solar system is a smashing success. A new study suggests that from its earliest period — even before the last of its nebular gas had been consumed — Earth’s solar system and its planets looked ...

We have all been taught in school that planets revolve in the same direction as the Earth, i.e., in the counterclockwise direction. However, the universe never ceases to amaze us with its unexpected ...