Astronomers believe that our solar system may still hold surprises ... Astronomers believe that Planet Nine could be 5-7 times the size of Earth and situated more than 200 times farther from ...

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.

And being so close to the sun, it will be difficult to see. With eight planets in our solar system, they all have some very interesting traits. Here's a quick look at the planets aligning on this ...

However, due to its size, Mercury also is the fastest planet in our solar system, orbiting the sun every 88 Earth days. Mercury formed about 4.5 billion years ago from swirling gas and dust.

The planets in our solar system orbit the sun essentially along a line across the sky in a plane called the ecliptic. For that reason, planets in our Earthly sky always appear somewhere along a ...

New research shows that star activity can distort exoplanet measurements, affecting size, temperature, and atmosphere ...

This may explain the strange properties of the orbits of our solar system's planets, which are not quite perfectly circular, and all lie on slightly different planes. NASA artist’s conception of ...

A planet parade is when several of our solar system's planets are visible in the night sky at the same time. There will be six planets visible this time around, including Venus, Mars, Jupiter ...