Why are they in a line? It's because the solar system is flat. I know, last week I outlined two experiments you can do to prove that the Earth is not flat. But the solar system really is flat.

Most of them are in single-star systems, like our own solar system. A few dozen orbit binary stars, dancing delicately around two suns. But the geometry is completely different.

This happens because the planets in our solar system essentially orbit the sun along the same line across a flat, disc-shaped plane in the sky known as the ecliptic, according to cosmic news site ...

Will there ever be a time when all the planets of our solar system line up in a row, one behind the other, as seen from Earth? (continued) Richard Swifte Darmstadt, Germany.

Currently, our solar system recognizes 8 planets, with Pluto being demoted to a dwarf planet floating in the Kuiper Belt in 2006. Planet Nine's gravitational pull may explain what keeps the icy ...

The Sun accounts for some 99.86% of the mass in our Solar System; of the remaining fraction of a percent, fully two-thirds is embodied in Jupiter, which itself contains more than 70% of the total ...

For a few evenings around 28 February, every planet in the solar system will be visible in the night sky, thanks to a rare great planetary alignment. Here's how to make sure you don't miss this ...

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.

Astronomers posed over the past decade that dark comets, or objects that resemble asteroids but move like comets, may exist. Now, scientists have found a total of 14 of them.