Hubble at 20
Take a look back at some of the most beautiful images taken by one of the world’s biggest space telescopes
An astronaut repairs Hubble as the telescope orbits the Earth.
For 20 years, the Hubble Space Telescope has given astronomers views of the universe they never dreamed possible. Hubble was one of the first—and biggest—telescopes of its kind.
Scientists have learned a lot about outer space using the powerful telescope. Hubble has provided new information about how stars and planets are born. It has discovered a star system 100 times bigger than our own solar system, and even spotted a huge cloud of oxygen—the main ingredient in the air we breathe—bigger than the Milky Way, the galaxy in which our solar system exists.
In 2008, Hubble also found the closest planet to us outside of our solar system. The planet was named Fomalhaut b and is believed to be three times the size of Jupiter, the largest planet in our solar system.
Why is the Hubble Space Telescope able to see so much farther into space than other telescopes? Most telescopes of Hubble's size are based on land. But Hubble floats in outer space, orbiting (circling) the Earth.
Hubble's photos are clearer than those of land-based telescopes because they are taken from high above Earth's atmosphere, the layer of gases that surrounds our planet. Ever notice how stars twinkle when you look up at night? Stars do not actually blink. But the atmosphere twists and warps what we see from Earth, making the stars look like they're blinking.
Space telescopes also do not have to compete with the light made by humans on Earth. Stars don't fade away in the daytime, but sunlight makes them hard to see. In the same way, light created by people brightens the sky at night, making stars appear less bright than they actually are.
Hubble was repaired for the last time in 2009. Astronauts updated or replaced many of Hubble's old and broken parts, which should allow the telescope to continue to provide images until at least 2014. That is the year when NASA—the U.S. space agency—plans to launch the James Webb Space Telescope to take Hubble's place.
Although Hubble will be replaced by newer space telescopes, the dazzling images it has provided will always be remembered. This single telescope has taken more than 30,000 images of the universe! Click here to see a slide show of some of Hubble's most memorable photos.