DEEP-SPACE PHOTOS: HUBBLE'S GREATEST HITS

The legendary space telescope celebrates its 20th year in orbit.

1. Black Hole

NASA/Goddard Space Flight Center

On April 24, 1990, the telescope named after the great astronomer Edwin Hubble burst through earth's atmosphere and it has been taking photos of the edges of the known Universe ever since. Shortly after its launch, the Hubble snapped a photo of NGC 4261, an elliptical galaxy in the Virgo Cluster. Although the telescope had a flawed mirror at the time, astronomers nevertheless were able to detect a super massive black hole at least half a billion times larger than the sun at the center of this galaxy.

See: A Brief History of the Hubble Space Telescope.

2. Eagle Nebula

Corbis

The Hubble orbits at around 370 miles above earth. Unlike previous telescopes, it can make digital photographs using light visible to the naked eye. And since it orbits above the earth's atmosphere, its photos are not obscured by smog, haze or light. For Jeff Hester, the astronomer responsible for this photo of the Eagle Nebula, taken just a few years after the telescope's first service mission, the image represents "the recovery of Hubble and the dreams that had originally accompanied its launch."

3. Saturn Aurora

Space Telescope Science Institute (STScI)/NASA

A large amount of solar wind activity from the sun creates a bright aurora around the south pole of the planet Saturn, rising more than a thousand miles above its cloud tops.

4. Butterfly Nebula

STScI/NASA/Corbis

Also known as the Bug Nebula, the butterfly-shaped nebula consists of heated gas made up of oxygen and nitrogen, the whole of which tears through space at speeds in excess of 60,000 miles an hour. The dying star in the center is not unlike our sun.

5. Deep Field View

STScI/NASA/Corbis

In 1995, the telescope peered into a tiny spot in the sky for ten days, which surprisingly revealed the existence of at least 10,000 galaxies, some billions of light years away. This is the deepest visible light image ever made.

6. Pluto

NASA

Taken in 2002 and 2003, this is the most detailed and highest resolution image of the entire surface of the dwarf planet Pluto, a member of the population of bodies that reside in a part of our Solar System known as the Kuiper Belt. It is believed that the methane on Pluto's surface is broken up by the ultraviolet radiation from the sun, leaving behind a dark, carbon-rich residue.

7. V838 Monocerotis

STScI/NASA/Corbis

In the beginning of 2002, a dull star floating some 20,000 light-years away from the sun, in the constellation Monceros, experienced a major outburst that threw illuminating dust or 'light echos' into space, temporarily making it the brightest star in the Milky Way galaxy. Since its explosion, this mysterious star's apparent brightness has changed to mere obscurity.

8. Horsehead Nebula

NASA

Located approximately 1,500 light-years from Earth in the constellation Orion, this dark nebula is one of the most photographed and identifiable nebulae; its cloud dust and gases form what appears to be a horsehead in the night sky.

9. Antennae Galaxies

NASA

Approximately 500 years ago, two galaxies collided together to form the Antennae galaxies in the constellation Corvus. They are the nearest and youngest example of galaxies fusing together to form what astronomers call interacting galaxies. In this process, billions of stars and star clusters are formed.

10. Crab Nebula

NASA/Jet Propulsion Laboratory (JPL)/Caltech/Corbis

In 1054 AD, Chinese astronomers witnessed a stellar explosion in the constellation Taurus. One thousand years later, the tattered remnants of the super dense neutron star's explosion, also known as a supernova, are still visible, sweeping up gas as they expand at a rate of 1,500 kilometers per second and rotating about 30 times per second.

11. Centaurus A

STScI/NASA

By looking deep into space, the Hubble has been able to photograph the past. Incredibly, with the help of Hubble, astronomers have been able to see what the universe looked like 600 million years after the Big Bang. It is believed that the firestorm of starbirth along the dark dust rift of Centaurus A is a result of a violent collision. Over 100 star formations have been identified here, mostly young stars in blue. The older, more evolved stars reside in the bulge of the galaxy, which also contains a super massive black hole at its center that is swallowing up a spiral galaxy containing millions of stars.

12. Jupiter's Moon

NASA/Hubble Space Telescope/Science Faction/Corbis

In 1610, the Italian astronomer Galileo Galilei observed Jupiter and four of its largest moons. The one called Io, (center) is the most geologically active in our Solar System, due to its many volcanoes. Although it appears to be skimming the planet's cloud tops, Io is actually 310,000 miles from the surface of Jupiter. The black dot to right center is the moon's shadow. It takes Io just 42.5 hours to revolve once around Jupiter.

13. Dark Matter and Dark Energy

AFP/Getty Images

The collection of photos taken by the Hubble includes some of the most detailed photographs ever taken of the things in our universe. In the 20 years since its launch, the Hubble has made close to 100 million images, confirming the existence of black holes, exoplanets, supernovae, nebulae, proplyds, and more recently, the existence of dark matter and energy.

[Source: TIME Photos]