Exoplanets are planets outside Earth's solar system. In 1995, a gas giant named 51 Pegasi b, which orbits a star similar to Earth's sun, etched its name in history as the first exoplanet ever ...

Earth may have a moon today because a nearby neighbor once crashed into us, a new analysis of Apollo samples and terrestrial rocks reveals. When you purchase through links on our site, we may earn an ...

The star system V1298 Tau reveals that many planets begin as large, low-density worlds that slowly shrink and shed their ...

The newborn planetary system appears to be emerging 1,300 light-years away around a baby star known as HOPS-315. Planet-forming materials were first identified using NASA's James Webb Space Telescope.

Astronomers believe they have uncovered evidence of a previously unknown ninth planet lurking in the not-too-distant reaches of the solar system. This hypothetical world, dubbed "Planet Y," could be ...

JWST observations of the ultra-hot super-Earth exoplanet TOI-561 b provide the strongest evidence to date for an atmosphere ...

Space has a knack for bending our sense of scale. The Moon feels close enough to touch—after all, we see its craters with nothing but our eyes. Yet, that 238,855-mile gap between Earth and its lunar ...

Are planets in the solar system that are closer to the Sun older than the ones further away? – Gavriel, age 10, Paducah, Kentucky A cloud of collapsing gas created our Sun, the first thing to form in ...

This artist’s impression shows a sunset seen from the super-Earth Gliese 667 Cc. Astronomers have estimated that there are tens of billions of such rocky worlds orbiting faint red dwarf stars in the ...

Which way is ‘down’ has a different answer depending on where you are on Earth, in the solar system, in our galaxy and beyond ...

At half the size of Earth and one-tenth its mass, Mars is a featherweight as far as planets go. Yet new research reveals the ...