A composite image of the Messier 81 (M81) galaxy shows what astronomers call a "grand design" spiral galaxy, where each of its arms curls all the way down into its centre. Located about 12 million light-years away in the Ursa Major constellation, M81 is among the brightest of the galaxies visible by telescope from Earth.

Sheets of debris from an exploded star swirl in the Large Magellanic Cloud (LMC) galaxy in this Hubble Space Telescope image. At a distance of about 180,000 light-years, the LMC galaxy is a relatively close neighbor of the Milky Way. It can be spotted from the Earth's Southern Hemisphere without a telescope.

This NASA/ESA Hubble Space Telescope image reveals the iridescent interior of one of the most active galaxies in our local neighbourhood — NGC 1569, a small galaxy located about eleven million light-years away in the constellation of Camelopardalis (The Giraffe). This galaxy is currently a hotbed of vigorous star formation. NGC 1569 is a starburst galaxy.

An infrared image of the Messier 82 galaxy, nicknamed the "Cigar galaxy," shows the formation's central plane in blue and white, with a halo of smoky dust in red. This red cloud, composed of hydrocarbon dust similar to car exhaust, is being blown out into space by the galaxy's millions of young stars.

A Hubble Space Telescope image shows unprecedented detail of the Antennae galaxies, an intense star-forming region created when two galaxies began to collide some 200 million to 300 million years ago. The bright, blue-white areas show newly formed stars surrounded by clouds of hydrogen, which are colored pink. A similar collision is expected between our galaxy, the Milky Way, and the nearby Andromeda galaxy in several billion years.

The Black Eye or Evil Eye galaxy gets its nicknames from the band of light-absorbing dust that appears in front of the star system's bright center in this Hubble Space Telescope image. Messier 64, as the Black Eye galaxy is more formally known, is thought to have taken on its ominous appearance after it collided with another galaxy perhaps a billion years ago.

Billows of cosmic dust swirl amid NGC 1316, a giant elliptical galaxy formed billions of years ago when two spiral galaxies merged. Astronomers examined red star clusters within NGC 1316 to determine that the massive galaxy was indeed created by a major celestial collision.

A face-on view of the Messier 74 galaxy shows billions of stars forming within its spiral arms. The clusters of blue are young stars, and the pink areas indicate concentrations of ionized hydrogen. Messier 74 is home to about a hundred billion stars, slightly fewer than the Milky Way has, and sits near the constellation Pisces some 32 million light-years away.

NASA’s Hubble Space Telescope has picked up the faint, ghostly glow of stars ejected from ancient galaxies that were gravitationally ripped apart several billion years ago. The mayhem happened 4 billion light-years away, inside an immense collection of nearly 500 galaxies nicknamed “Pandora’s Cluster,” also known as Abell 2744.

This 2008 illustration shows a revised look at our galaxy, the Milky Way. Scientists studying infrared images from NASA's Spitzer Space Telescope determined our galaxy's spiral has two major and two minor arms instead of four major arms, as was previously thought. The demoted arms can be seen as faint trails between the major arms, which emanate from the ends of the orange central bar.

A colour-composite image shows the NGC 300 galaxy, a spiral galaxy like the Milky Way located about seven million light-years from Earth. In this image, young, hot stars are the blue dots that comprise much of the outer arms. Older stars are in the middle and appear yellow-green.

The Andromeda galaxy, also known as Messier 31, is the largest neighboring galaxy to the Milky Way. This photo, a mosaic of ten images captured by the Galaxy Evolution Explorer spacecraft in 2003, shows blue-white regions along the galaxy's arms where new stars are forming and a central orange-white area containing older, cooler stars.