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

Researchers studying decades of earthquake data say they have found the first evidence that, in addition to spinning backward ...

An object eight times the mass of Jupiter may have swooped around the sun, coming superclose to Mars' present-day orbit ...

This solar system consists of four inner rocky planets and four outer gas giant planets as well as an asteroid belt, containing thousands of huge rocks, dwarf planets and comets. Our solar system ...

While the composition of gas and dust in a molecular cloud is fairly uniform, everything changes once a star begins to form.

These embryos, somewhere between small planetesimals and fully formed planets, were abundant ... they could only have formed in the inner solar system. "Angrites are a small group of ancient ...

In reality, they are an ordinary and predictable part of living in a solar system. Dr ... the Sun while Neptune takes nearly 165 years. Right now, the outer planets are all on relatively the same side ...

The enormous visitor to our solar system may have been about 8 times the mass of Jupiter, and come nearly as close to the sun as the orbit of Mars.

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.

The discovery of two new planets beyond our solar system by a team of astronomers ... The existence of these two exoplanets - an inner super-Earth and an outer icy giant planet - within the ...

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 ...