A cloud of collapsing gas created our Sun, the first thing to form in our solar system. ... The inner planets, including Earth, took at least 100 million years, maybe more.

Close stellar encounters could change the structure of our planetary system, potentially dooming Earth or other worlds to ...

Rocky bodies called protoplanets were thought to have formed slightly earlier in the inner solar system than those beyond the ...

Formation of the solar system in two different planetary populations: the inner rocky planets formed earlier than the outer gas and ice giants. (Illustration: Mark A. Garlick / markgarlick.com ...

In multi-planet systems, these orbits tended to be much closer together than they are in our solar system. For instance, the star known as Kepler-11 has six planets closer to it than Venus is to ...

Stars passing close to the sun could cause planets to collide, including with Earth, or even be ejected as rogue planets, new ...

A fifth giant planet was kicked out of the early solar system, according to computer simulations by a US-based planetary scientist. The sacrifice of this gas giant paved the way for the stable ...

There may be another world lurking between the orbital lines of our solar system. Astronomers in Japan have published their theory of an “Earth-like planet,” dubbed Planet Nine, that’s ...

Learn how a possible ninth planet, the theoretical Planet X, could have acquired its wide orbit in the outer Solar System - a process that's also applicable for other planets.

And finally, the dwarf planets in the outer solar system are still growing slowly. Nailing down this sequence of events is of consequence for exoplanetary systems as well, which we can study with ...

Are planets in the solar system that are closer to the Sun older than the ones further away? – Gavriel, age 10, Paducah, Kentucky A cloud of collapsing gas created our Sun, the first thing to ...

– Gavriel, age 10, Paducah, Kentucky A cloud of collapsing gas created our Sun, the first thing to form in our solar system. This happened about 4½ billion years ago. Then the planets began to ...