This image of the Antennae galaxies is the sharpest yet of this merging pair of galaxies. During the course of the collision, billions of stars will be formed. The brightest and most compact of these star birth regions are called super star clusters. The two spiral galaxies started to interact a few hundred million years ago, making the Antennae galaxies one of the nearest and youngest examples of a pair of colliding galaxies. NASA/ESA/Newscom
This image from NASA's Hubble Space Telescope and its Wide Field Planetary Camera 2 shows the unique galaxy pair called NGC 3314. Through an extraordinary chance alignment, a face-on spiral galaxy lies precisely in front of another larger spiral. This line-up provides us with the rare chance to visualize dark material within the front galaxy, seen only because it is silhouetted against the object behind it. Newscom
This false-color image taken by NASA's Spitzer Space Telescope shows the South Pillar region of the star-forming region called the Carina Nebula. Though the nebula's most famous and massive star, Eta Carinae, is too bright to be observed by infrared telescopes, the downward-streaming rays hint at its presence above the picture frame. Ultraviolet radiation and stellar winds from Eta Carinae and its siblings have shredded the cloud to pieces, leaving a mess of tendrils and pillars. This shredding process triggered the birth of the new stars uncovered by Spitzer. UPI Photo/NASA
This photo from the Advanced Camera for Surveys on the Hubble Space Telescope shows a pillar of gas and dust called the Cone Nebula which resides in a turbulent star-forming region. Newscom
A collision between two spiral galaxies, NGC 6050 and IC 1179 part of the Hercules Galaxy Cluster, was taken by the Hubble Space Telescope. The two spiral galaxies are linked by their swirling arms. Arp 272 is located some 450 million light-years away from Earth and is the number 272 in Arp's Atlas of Peculiar Galaxies. HUBBLE/AFP/Getty Images
At the center of spiral galaxy M81 is a supermassive black hole about 70 million times more massive than our sun. A new study using data from Chandra and ground-based telescopes, combined with detailed theoretical models, shows that the supermassive black hole in M81 feeds just like stellar mass black holes, with masses of only about ten times that of the sun. This discovery supports Einstein's relativity theory that states black holes of all sizes have similar properties. Newscom
A NASA Hubble Space Telescope view of a turbulent cauldron of starbirth, taking place 170,000 light-years away in our satellite galaxy, the Large Magellanic Cloud. Torrential stellar winds from hot newborn massive stars within the nebula sculpt ridges, arcs, and filaments in the vast cloud, which is over 150 light-years across. A rare type of compact ionized 'blob' is resolved for the first time to be a butterfly-shaped nebula, buried in the center of the maelstrom of glowing gases and dark dust. Edisto Images
A collision of two galaxies has left a merged star system with an unusual appearance as well as bizarre internal motions. Messier 64 has a spectacular dark band of absorbing dust in front of the galaxy's bright nucleus, giving rise to its nicknames of the 'Black Eye' or 'Evil Eye' galaxy. Newscom
This undated NASA image obtained from the Chandra X-Ray Observatory shows galaxy Centaurus A and an active supermassive black hole. Opposing jets of high-energy particles can be seen extending to the outer reaches of the galaxy, and numerous smaller black holes in binary star systems are also visible. Centaurus A is the nearest galaxy to Earth that contains a supermassive black hole actively powering a jet. UPI Photo/NASA
An image taken by Hubble Space telescope and released on October 30, 2008 by European Space Agency, shows a pair of gravitationally interacting galaxies called Arp 147, photographed on October 27-28, 2008. Arp 147 lies in the constellation of Cetus, more than 400 million light-years away from Earth. LIVIO/AFP/Getty Images
This picture released on April 24, 2008 by ESA shows the staggering aftermath of an encounter between two galaxies, resulting in a ring-shaped galaxy and a long-tailed companion. The collision between the two parent galaxies produced a shockwave effect that first drew matter into the centre and then caused it to propagate outwards in a ring. HUBBLE/AFP/Getty Images
New research suggests that galaxies hold more 'normal matter' than scientists could image. This matter in the form of gas resides in halos that turn out to be about twice as vast as previously estimated.
Spiral galaxies like the Milky Way appear to host far more ordinary matter than previously estimated, according to a recent study. That may help explain why spiral galaxies in the nearby universe are still producing stars at respectable rates when, by all rights, star formation in these galaxies should have run out of gas billions of years ago.