At only four light-years away, Proxima b is our closest known exoplanet neighbor.

Up-close picture of Kepler CCD hardware.

Since a giant planet in a scorching orbit captured public attention in 1995, a sky full of strange and exotic exoplanets – planets orbiting other stars – has only grown richer in variety and detail.

The first Earth-size planet discovered around a near solar twin, the discovery of Kepler-452b brings us closer than ever to finding an Earth-like planet.

On August 25, 2003, NASA launched the Spitzer Space Telescope to reveal secrets of the infrared universe.

Kepler-7b (left), which is 1.5 times the radius of Jupiter (right), is the first exoplanet to have its clouds mapped. This artist's concept shows what those clouds might look like. The cloud map wa...

This illustration shows three possible scenarios for the evolution of asteroid belts.

This artist's concept shows how astronomers use the unique orbit of NASA's Spitzer Space Telescope and a depth-perceiving trick called parallax to determine the distance of dark planets, black hole...

An artist's impression of a red supergiant engulfing a Jupiter-like planet as it expands.

Astronomers have discovered two gas giant planets orbiting stars in the Beehive cluster, a collection of about 1,000 tightly packed stars.

Animation of HAT-P-7 light curve showing both large transit dip and small occultation dip.

The artist's concept depicts a comet-like tail of a possible disintegrating super Mercury-size planet candidate as it transits its parent star named KIC 12557548.

Ball Aerospace team assembles Kepler spacecraft

Kepler does not orbit the Earth, rather it orbits the Sun in concert with the Earth, slowly drifting away from Earth. Every 61 Earth years, Kepler and Earth will pass by each other.

This is an artist's impression of the view from the vicinity of a hypothetical terrestrial planet and moon orbiting the red dwarf star AU Microscopii.

This artists impression shows the free-floating planet CFBDSIR J214947.2-040308.9. This is the closest such object to the Solar System.

This infographic explains how NASA's Spitzer Space Telescope can be used in tandem with a telescope on the ground to measure the distances to planets discovered using the "microlensing" technique.

This plot of data from NASA's Spitzer Space Telescope indicates the presence of molecules in the planet WASP-12b -- a super-hot gas giant that orbits tightly around its star.

This is the animated storybook tale of the Spitzer spacecraft and its exploits as part of the space telescope superteam known as NASA’s Great Observatories, which also includes Hubble, Chandra and ...

This slide breaks down and explains what black holes are.

Transit data are rich with information. By measuring the depth of the dip in brightness and knowing the size of the star, scientists can determine the size or radius of the planet. The orbital peri...

Kepler arriving at the Kennedy Space Center.

NASA's Kepler mission has discovered a world where two suns set over the horizon instead of just one.

Artist's rendering of the planetary system HR 8799 at an early stage of its evolution, showing the planet HR879cc, a disk of gas and dust, and interior planets.

Kepler does not directly observe the image of a planet. Rather it observes the effect the planet has on its parent star. If the orbit of the planet is aligned along Kepler's line of sight to the st...