Hubble is the first major optical telescope in space. Above the distortion of the atmosphere, far above clouds and light pollution, Hubble has an unobstructed view of the universe.

NASA's Spitzer Space Telescope, launched in 2003, assisted in the discovery of planets beyond our solar system, including the detection of seven Earth-size planets orbiting the star TRAPPIST-1.

The doomed egg-shaped exoplanet WASP-12b is a hot Jupiter that orbits so close to its parent star, it's being torn apart.

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

55 Cancri e is a super Earth exoplanet that orbits a G-type star. Its mass is 8.08 Earths, it takes 0.7 days to complete one orbit of its star, and is 0.01544 AU from its star. Its discovery was announced in 2004.

When we talk about the enormity of the cosmos, it’s easy to toss out big numbers – but far more difficult to wrap our minds around just how large, how far and how numerous celestial bodies really are.

Planet Janssen, or 55 Cancri e, orbits a star called Copernicus only 41 light years away. 

During 9.6 years in orbit, the Kepler space telescope observed more than half a million stars and discovered more than 2,600 planets. See the mission by the numbers.

NASA Associate Administrator Thomas Zurbuchen and TESS Project Scientist Padi Boyd discuss Kepler's legacy, the search for life and the big question: Are we alone?

The stars TESS studies are 30 to 100 times brighter than those the Kepler mission and K2 follow-up surveyed, enabling far easier follow-up observations with both ground-based and space-based telescopes. TESS will also cover a sky area 400 times larger than that monitored by Kepler.

NASA's Kepler mission revealed that there are more planets than stars in our galaxy. It opened our eyes to diverse worlds – some entirely unlike planets found in our solar system.

The Kepler space telescope will remain for decades in orbit around the Sun, weaving in and out of Earth’s orbital path.

Launched in March 2009, NASA’s first planet-hunter confirmed more than 2,600 planets beyond our solar system. "Many stars have planets. A lot of these planets are Earth-sized. That's Kepler's legacy. This new knowledge that we have about planets around other stars."

Send your love with a habitable planet valentine.

Tell someone they're unique, with our Earth valentine.

Keep your Valentine close with a tidally-locked planet, that always faces its star.

Celebrate your rocking single status with a rogue planet, the world without a star.

For Valentine's Day, give the tight-knit Kepler-11 to your faves.

Celebrate Valetine's Day with a hot Jupiter that tightly hugs its star.

Meet the astronauts, mathematicians, and directors leading NASA's most innovative missions to space.

Kepler-186f is the first Earth-size planet discovered in the potentially 'habitable zone' around another star, where liquid water could exist on the planet's surface. Its star is much cooler and redder than our Sun. If plant life does exist on a planet like Kepler-186f, its photosynthesis could have been influenced by the star's red-wavelength photons, making for a color palette that's very different than the greens on Earth. This discovery was made by Kepler, NASA's planet hunting telescope.

This artist's concept shows what the weather might look like on cool star-like bodies known as brown dwarfs. These giant balls of gas start life like stars, but lack the mass to sustain nuclear fusion at their cores, and instead, fade and cool with time.

Artistic rendering of a planet's transmission spectrum

Researchers are getting to know some of our sun's closest and smallest neighbors.

Astronomers detect lowest-mass planet around a star like the sun found using direct imaging techniques.