Classic Hubble Hits

The Hubble Space Telescope is celebrating its 20th birthday and we have some images taken by the iconic space observatory over the past two decades. Arp 148, shown here, is the staggering aftermath of an encounter between two galaxies, resulting in a ring-shaped galaxy and a long-tailed companion. This image is part of a collection of 59 images of merging galaxies taken by Hubble and released on its 18th anniversary.

AM 0500-620, located 350 million light-years away from Earth, consists of a highly symmetric spiral galaxy seen nearly face-on and partially backlit by a background galaxy.

This Hubble image displays a beautiful pair of interacting spiral galaxies with swirling arms. The smaller of the two, dubbed LEDA 62867 and positioned to the left of the frame, seems to be safe for now, but will probably be swallowed by the larger spiral galaxy, NGC 6786 (to the right) eventually.

This image shows a Hubble view of Arp 272, a remarkable collision between two spiral galaxies, NGC 6050 and IC 1179. The galaxy cluster is part of the Great Wall of clusters and superclusters, the largest known structure in the Universe. The two spiral galaxies are linked by their swirling arms.

NGC 520 is the product of a collision between two disk galaxies that started 300 million years ago. It exemplifies the middle stages of the merging process: the disks of the parent galaxies have merged together, but the nuclei have not yet coalesced. It features an odd-looking tail of stars and a prominent dust lane that runs diagonally across the center of the image and obscures the galaxy.

This is the sharpest image yet from the Hubble Space Telescope of the merging Antennae galaxies. As the two galaxies smash together, billions of stars are born, mostly in groups and clusters of stars. The brightest and most compact of these are called super star clusters.

This photo of the starburst galaxy, Messier 82 (M82) is the sharpest wide-angle view ever obtained of M82, a galaxy remarkable for its webs of shredded clouds and flame-like plumes of glowing hydrogen blasting out from its central regions. Located 12 million light-years away, it is also called the "Cigar Galaxy" because of the elongated elliptical shape produced by the tilt of its starry disk relative to our line of sight.

This Hubble Space Telescope image released February 28, 2006, shows the spiral galaxy of the Messier 101. It is the largest and most detailed photo of a spiral galaxy that has ever been released from Hubble.

This image bears remarkable similarities to the Vincent van Gogh work, "Starry Night" complete with never-before-seen spirals of dust swirling across trillions of kilometres of interstellar space. The Advanced Camera for Surveys is Hubble's latest view of an expanding halo of light around a distant star, named V838 Monocerotis (V838 Mon). V838 Mon is located about 20,000 light-years away from Earth in the direction of the constellation Monoceros, placing the star at the outer edge of our Milky Way galaxy.

NASA's Hubble Space Telescope trained its eye on one of the universe's most stately and photogenic galaxies, the Sombrero galaxy with the space telescope's Advanced Camera for Surveys , in May-June 2003 . The image of the galaxy's hallmark brilliant white, bulbous core is encircled by the thick dust lanes comprising the spiral structure of the galaxy.

This dramatic image offers a peek inside a cavern of roiling dust and gas where thousands of stars are forming. The image, taken by the Advanced Camera for Surveys aboard the Hubble Space Telescope, represents the sharpest view ever taken of this region, called the Orion Nebula.

Columns of cool hydrogen gas in the Eagle Nebula serve as the incubators for new stars - which look like tiny bubbles within the dark pillars.

In the left image, the Cartwheel Galaxy looks like a wagon wheel in space. A more detailed image of the galaxy"s hub shows bright, comet-like clouds circling at nearly 700,000 mph.

A nebula known as the Cygnus Loop is actually the expanding blast wave from a supernova. The blast has hit a cloud of dense interstellar gas-causing the gas to glow.

Pictured is an image of the Helix Nebula showing tremendous detail of its mysterious gaseous knots. The cometary knots have masses similar to the Earth but have radii typically several times the orbit of Pluto.

Eta Carinae was the site of a giant outburst observed from Earth about 150 years ago, when it became one of the brightest stars in the southern sky. The star survived the explosion, which produced two billowing clouds of gas and dust.

HH 32 is an excellent example of a "Herbig-Haro object," which is formed when young stars eject jets of material back into interstellar space. The jets plow into the surrounding nebula, producing strong shock waves that heat the gas and cause it to glow in different colors.

This celestial object, with the scientific name MyCn18, looks like an eerie green eye staring out from two intersecting rings. But it's actually an intricately shaped "hourglass" nebula with a star at its center.

Temperature differences within interstellar clouds of gas and dust can result in structures reminiscent of Earth's tornadoes. Here are some twisters in the heart of the Lagoon Nebula.

The small spiral galaxy NGC 7742 is probably powered by a black hole residing in its core. The core of NGC 7742 is the large yellow "yolk" in the center of this fried-egg image.

A spiral-shaped disk of dust fuels what scientists believe is a black hole near the center of the galaxy NGC 4261. The material heats up and glows as it swirls around the black hole.

Like lanterns in a cavern, scores of hot stars light up the gaseous walls of the nebula NGC 604. The nebula is a prime area for starbirth in an arm of the spiral galaxy M33.

Three rings of glowing gas encircle the site of supernova 1987A, a star that was seen to explode in 1987. Though the rings appear to intersect, they are probably in three different planes.

A false-color image shows infrared light reflected from the planet Saturn. The different hues help scientists discern different levels of the planet's thick atmosphere. Two of Saturn's moons - Dione and Tethys - are visible as specks on the image.

A curtain of glowing gas is wrapped around Jupiter's north pole like a lasso in a Hubble Space Telescope image captured in 1998. The curtain of light, called an aurora, is produced when high-energy electrons race along the planet's magnetic field and into the upper atmosphere. The electrons excite atmospheric gases, causing them to glow. A similar aurora crowns Earth's polar regions.

The Horsehead Nebula is one of the most photographed objects in the sky. The Hubble Space Telescope took a close-up look at this heavenly icon, revealing the cloud's intricate structure. This view of the horse's head was released April 24, 2001, to celebrate the observatory's 11th anniversary. Hubble was launched by the shuttle Discovery on April 24, 1990.