Our solar system’s origin story spans billions of years and involves clouds of gas, cosmic collisions, and planetary ...

Learn how a possible ninth planet, the theoretical Planet X, could have acquired its wide orbit in the outer Solar System - a ...

The planets, for instance, revolve in the same direction and in almost the same plane. The four inner ones (Mercury, Venus, Earth, Mars) are smaller and denser than the outer ones (Jupiter ...

A cloud of collapsing gas created our Sun, the first thing to form in our solar system. This happened about 4½ billion years ...

A new analysis of planet formation models estimates the odds of a theoretical Planet Nine orbiting our sun at 40% given ...

The gravitational games of the outer planets removed many of those protoplanets from the inner solar system, but plenty were left behind. And then came the collisions. The researchers found that ...

Inner planets are the four planets closest to the Sun: Mercury, Venus, Earth and Mars. They are collectively characterized by a solid surface and small size relative to the outer gas giants.

The presence of water-ice in the debris disk around a young star could have helped facilitate the growth and development of ...

But the liquid outer core is shrinking ... be obliterated as our sun expands into a red giant and swallows the inner planets of the solar system, Vidale said. Until then, scientists should ...

If the core froze relatively recently, the current thermal state at the inner core–outer core boundary indicates ... cores and magma oceans of rocky planets which facilitate habitable conditions ...