NGC 7674: NGC 7674 (seen just above the centre), also known as Markarian 533, is the brightest and largest member of the so-called Hickson 96 compact group of galaxies, consisting of four galaxies. This stunning Hubble image shows a spiral galaxy nearly face-on. The central bar-shaped structure is made up of stars. The shape of NGC 7674, including the long narrow streamers seen to the left of and below the galaxy can be accounted for by tidal interactions with its companions. NGC 7674 has a powerful active nucleus of the kind known as a type 2 Seyfert that is perhaps fed by gas drawn into the centre through the interactions with the companions. NGC 7674 falls into the family of luminous infrared galaxies and is featured in Arp's Atlas of Peculiar Galaxies as number 182. It is located in the constellation of Pegasus, the Winged Horse, about 400 million light-years away from Earth. This image is part of a large  collection of 59 images of merging galaxies taken by the Hubble Space Telescope and released on the occasion of its 18th anniversary on 24th April 2008.

Name: Arp 182, NGC 7674
Type: Local Universe : Galaxy : Type : Interacting
Category: AnniversaryGalaxies
Constellation: Pegasus
Distance: 350 million light years
Release date: 24 April 2008, 15:00
Credit: NASA, ESA, the Hubble Heritage Team (STScI/AURA)-ESA/Hubble Collaboration and A. Evans (University of Virginia, Charlottesville/NRAO/Stony Brook University)

UGC 4881: UGC 4881, known as the "The Grasshopper", is a stunning system consisting of two colliding galaxies. It has a bright curly tail containing a remarkable number of star clusters. The galaxies are thought to be halfway through a merger - the cores of the parent galaxies are still clearly separated, but their discs are overlapping. A supernova exploded in this system in 1999 and astronomers believe that a vigorous burst of star formation may have just started. This notable object is located in the constellation of Lynx, some 500 million light-years away from Earth. UGC 4881 is the 55th galaxy in Arp's Atlas of Peculiar Galaxies. This image is part of a large  collection of 59 images of merging galaxies taken by the Hubble Space Telescope and released on the occasion of its 18th anniversary on 24th April 2008.

Name: Arp 55, UGC 4881, VV 155
Type: Local Universe : Galaxy : Type : Interacting
Category: AnniversaryGalaxies
Constellation: Lynx
Distance: 500 million light years
Release date: 24 April 2008, 15:00
Credit: NASA, ESA, the Hubble Heritage Team (STScI/AURA)-ESA/Hubble Collaboration and A. Evans (University of Virginia, Charlottesville/NRAO/Stony Brook University)

UGC 5101: UGC 5101 is a peculiar galaxy with a single nucleus contained within an unstructured main body that suggests a recent interaction and merger. NGC 5101 is thought to contain an active galactic nucleus - an extremely bright, compact core - buried deep in the gas and dust. A pronounced tail extends diagonally to the top-left of the frame. A fainter halo of stars surrounds the galaxy and is visible in the image, due to Hubble's ability to collect and detect faint light. This halo is probably a result of the earlier collision. UCG 5101 is about 550 million light-years away from Earth. This image is part of a large  collection of 59 images of merging galaxies taken by the Hubble Space Telescope and released on the occasion of its 18th anniversary on 24th April 2008.

Name: UGC 5101
Type: Local Universe : Galaxy : Type : Interacting
Category: AnniversaryGalaxies
Constellation: Ursa Major
Distance: 500 million light years
Release date: 24 April 2008, 15:00
Credit: NASA, ESA, the Hubble Heritage Team (STScI/AURA)-ESA/Hubble Collaboration and A. Evans (University of Virginia, Charlottesville/NRAO/Stony Brook University)

VV 283: VV 283 looks like a single peculiar galaxy, but is in fact a pair of merging galaxies. A tidal tail swirls out from a messy central region and splits into two branches. The upward twisting branch is brightened by luminous blue star knots. Like many merging systems, VV 283 is a very luminous infrared system, radiating nearly one thousand billion times energy more than our Sun. VV 283 is located in the constellation of Virgo, the Maiden, some 500 million light-years away. This image is part of a large  collection of 59 images of merging galaxies taken by the Hubble Space Telescope and released on the occasion of its 18th anniversary on 24th April 2008.

Name: MCG+01-33-036, VV 283
Type: Local Universe : Galaxy : Type : Interacting
Category: AnniversaryGalaxies
Constellation: Virgo
Distance: 500 million light years
Release date: 24 April 2008, 15:00
Credit: NASA, ESA, the Hubble Heritage Team (STScI/AURA)-ESA/Hubble Collaboration and A. Evans (University of Virginia, Charlottesville/NRAO/Stony Brook University)

NGC 5754: This beautiful pair of interacting galaxies consists of NGC 5754, the large spiral on the top and NGC 5752, the smaller companion in the bottom left corner of the image. NGC 5754's internal structure has hardly been disturbed by the interaction. The outer structure does exhibit tidal features, as does the symmetry of the inner spiral pattern and the kinked arms just beyond its inner ring. In contrast, NGC 5752 has undergone a starburst episode, with a rich population of massive and luminous star clusters clumping around the core and intertwined with intricate dust lanes. The contrasting reactions of the two galaxies to their interaction are due to their differing masses and sizes. NGC 5754 is located in the constellation Boötes, the Herdsman, some 200 million light-years away. This image is part of a large  collection of 59 images of merging galaxies taken by the Hubble Space Telescope and released on the occasion of its 18th anniversary on 24th April 2008.

Name: NGC 5754
Type: Local Universe : Galaxy : Type : Interacting
Category: AnniversaryGalaxies
Constellation: Bootes
Distance: 200 million light years
Release date: 24 April 2008, 15:00
Credit: NASA, ESA, the Hubble Heritage Team (STScI/AURA)-ESA/Hubble Collaboration and W. Keel (University of Alabama, Tuscaloosa)

AM1316-241: AM1316-241 is made up of two interacting galaxies - a spiral galaxy (on the left of the frame) in front of an elliptical galaxy (on the right of the frame). The starlight from the background galaxy is partially obscured by the bands and filaments of dust associated with the foreground spiral galaxy. The Hubble image unravels the fine detail in the patchy clumps of dust confined to the spiral arms of the spiral galaxy. This dust reddens the light from the background just as the intervening dust in the Earth's atmosphere reddens sunsets here. AM1316-241 is located some 400 million light years away toward the constellation of Hydra, the Water Snake. This image is part of a large  collection of 59 images of merging galaxies taken by the Hubble Space Telescope and released on the occasion of its 18th anniversary on 24th April 2008.

Name: AM1316-241, ESO 508-45
Type: Local Universe : Galaxy : Type : Interacting
Category: AnniversaryGalaxies
Constellation: Hydra
Distance: 350 million light years
Release date: 24 April 2008, 15:00
Credit: NASA, ESA, the Hubble Heritage Team (STScI/AURA)-ESA/Hubble Collaboration and W. Keel (University of Alabama, Tuscaloosa)