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

Watch this video to find out more about the Earth, planets in our Solar System and other planets far ... Some are the size of small stones and pebbles. Some measure hundreds of kilometres across.

ISTOCK / GETTY IMAGES PLUS The planets in our solar system orbit the sun in roughly the same plane, known as the ecliptic, which is tilted relative to Earth's equator by about 23.5 degrees.

But such events are not just a spectacle for stargazers – they can also have a real impact on our Solar System ... size and orbit to be discerned. Thanks to this method, we have discovered many ...

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

The team’s simulations allowed for four, five or size planets ... in which our own solar system formed. But early such clusters are tumultuous places. In a dense cluster, planets will become ...

"Relatively small planets similar to the size of Earth are ... There are nearly 300 moons in our solar system, but their masses are typically much smaller relative to their host planets than ...

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.

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

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 ...