How Many Planets Are There in the Solar System? There are 8 planets in our solar system. The planets orbit the Sun in elliptical trajectories, and they are all different in size, composition, ...

In the remote outer reaches of planetary systems, far beyond the orbit of known planets, enormous and mysterious worlds ...

Artist's impression of Planet Nine – a suspected “wide-orbit” planet – with the Sun in the distance; Neptune's orbit is shown ...

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

For decades it was thought that water was prevalent in the outer reaches of the Solar System early in its history, with comets and asteroids delivering moisture to Earth and the inner planets during ...

Our Solar System is full of mysteries, but if the inner planets are a puzzle, the boundary between the Solar System and interstellar space is a secondhand puzzle with half the pieces missing.

Our solar system is looking increasingly like an oddball.” The new paper explains not only the “gaping hole” in our inner solar system, he said, but also certain characteristics of Earth and the other ...

Astronomers discovered that C/2014 UN271, a massive comet more than 10 times larger than any known comet, is emitting jets of ...

This process, called accretion, is how everything in the solar system – planets, moons, comets and asteroids – came into being. Telescopes can see young solar systems being born.

NASA artist’s conception of a brown dwarf (main) and stock image of the planets in the solar system (inset). An object between 2 and 50 times the mass of Jupiter may have flown through our ...

How far away it is: 93 million miles (150 million km) ...