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

Canadian astronomers have taken an extraordinary step in understanding how planets are born, using the James Webb Space ...

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

An object eight times the mass of Jupiter may have swooped around the sun, coming superclose to Mars' present-day orbit before shoving four of the solar system's planets onto a different course.

These embryos, somewhere between small planetesimals and fully formed planets, were abundant during the solar system's formative stages and played a critical role in planetary formation.

All of our solar system’s planets are lining up to parade through the night sky at once. This extraordinary celestial event will see the sky scattered with seven visible planets in what is known ...

Four planets will be widely visible to the naked eye through part of February, but calling them a 'planetary alignment' may not be the full picture.

Stargazers will be treated to a dazzling six-planet "alignment" this January.

However, this year a powerful new telescope is coming online that could prove once and for all that there really is a ninth planet in our Solar System. The same year that Pluto was ignominiously ...

It is the fastest wind ever measured in a jetstream that goes around a planet. In comparison, the fastest wind ever measured in the Solar System was found on Neptune, moving at 'only' 0.5 km per ...

A planet-size object that possibly once visited the solar system may have permanently changed our cosmic neighborhood by warping the orbits of the four outer planets, a new study suggests.