The number of planets that orbit the sun depends on what you mean by “planet,” and that’s not so easy to define ...

We typically think of the Oort cloud as scattered ice balls floating far from the sun, yet still tied to it gravitationally.

In the paper, the researchers describe how they modeled the orbits of the four outer planets and performed ... which plunged deep into the inner solar system as it traveled.

Onward and outward, Jupiter rides high to the south in Taurus the Bull at dusk. The waxing near First Quarter Moon meets ...

This provides another piece of the puzzle to understand how planets and ... New studies offer a clearer picture of how the outer solar system formed and evolved based on analyses of trans ...

Scientists believe that two asteroids might be fragments of long-lost "planetary embryos" from the early solar system.

The planets in our solar system orbit the sun essentially along a line across the sky in a plane called the ecliptic. For that reason, planets in our Earthly sky always appear somewhere along a ...

Many of these near-match scenarios had the object zooming through the inner solar system, which prompted the researchers to add the terrestrial planets — Mercury, Venus, Earth and Mars — into ...

Using computer models of the four outer planets, the team carried out 50,000 ... had the planet-like object swooping through the inner solar system, the researchers created an additional 10,000 ...

The seven planets will not be perfectly aligned ... to take a "grand tour" of the outer Solar System on the occasion of a similar planetary alignment of Jupiter, Saturn, Uranus and Neptune.