The event, titled "Out of This World," will feature the Massapequa Philharmonic performing composer Gustav Holst's masterwork ...

But the overall point of this video – to show just how relative size really is, and how unimaginably large celestial objects really are – is pretty much spot-on.

These planets are about the size of Earth, and fall in the so-called “Goldilocks zone” of habitability, making them candidates to contain life.

A team of astronomers has measured the mass and size of a Mars-sized planet orbiting a red dwarf star about 200 light years from our solar system.

A fantastic map from webcomic artist Randall Munroe shows the relative surface areas of all the rocky planets and moons in the solar system as though they were continents branching off from the ...

Between them is a dip or valley, at around 1.8 times the radius of Earth, signifying the relative scarcity of planets of that size.

Harvard University researchers described a new, lower size limit for planets to maintain surface liquid water for long periods of time, extending the so-called Habitable or 'Goldilocks'' Zone for ...

Newly discovered planet is nearly 25 percent the size of its star How does a gas giant form near a dwarf star?

Gaseous planets close to their star could see their hydrogen atmospheres evaporate, leaving behind helium that could be detected by the James Webb Space Telescope.

The Kepler space telescope has spotted over 1,000 exoplanets beyond our solar system, and its latest finds are three almost Earth-sized planets, including one in the habitable zone circle the star ...