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

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 ...

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 ...

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

When you purchase through links on our site, we may earn an affiliate commission. Here’s how it works. A planet-size object that possibly once visited the solar system may have permanently ...

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 ...

This places it between Earth and Neptune in a size range that typically divides exoplanets ... expands our understanding of the diversity of planets (just like this strange object in our Solar System) ...