The Whirlpool galaxy, shown here, is an example of a classic spiral galaxy. At only 30 million light years distant and fully 60,000 light years across, M51, also known as NGC 5194, is among the brightest and most picturesque galaxies on the sky. This image is a digital combination of a ground-based image from the 0.9-meter telescope at Kitt Peak National Observatory and a space-based image from the Hubble Space Telescope highlighting sharp features normally too red to be seen. NASA/Hubble/Reuters
The Andromeda galaxy is shown in this NASA handout released April 29, 2013, from the Herschel space observatory. Cool lanes of forming stars are revealed in the finest detail yet. Herschel is a European Space Agency mission with NASA participation. Andromeda, also known as M31, is the nearest major galaxy to our own Milky Way, at a distance of 2.5 million light-years. ESA/Herschel/PACS & SPIRE Consortium, O. Krause, HSC, H. Linz/Reuters
An image released by NASA shows the Heart and Soul nebulae in an infrared mosaic from NASA's Wide-field Infrared Survey Explorer (WISE). The image covers an area of the sky in the constellation Cassiopeia that is more than 10 times as wide as the full moon and eight times as high. Located about 6,000 light-years from Earth, the Heart and Soul nebulae form a vast star-forming complex that makes up part of the Perseus spiral arm of our Milky Way galaxy. The nebula to the left is the Heart, designated IC 1805 and named after its resemblance to a human heart. To the right is the Soul nebula, also known as the Embryo nebula, IC 1848 or W5. NASA/JPL-Caltech/UCLA Heart and Soul Nebula/AP
A composite image of a galaxy illustrates how the intense gravity of a supermassive black hole can be tapped to generate immense power. The photo, released by NASA May 15, 2013, contains X-ray data from NASA's Chandra X-ray Observatory (blue), optical light obtained with the Hubble Space Telescope (gold), and radio waves from the National Science Foundation’s Very Large Array (pink). This multi-wavelength view shows a galaxy located some 850 million light-years from Earth. The radio emission comes from two jets of particles that are speeding at millions of miles per hour away from a supermassive black hole at the center of the galaxy. NASA/Reuters
This photo from the Hubble Space Telescope shows the deepest image of the universe ever taken in near-infrared light. The faintest and reddest objects in the image are galaxies that formed 600 million years after the big bang. No galaxies have been seen before at such early times. The new deep view also provides insights into how galaxies grew in their formative years early in the universe's history. NASA/European Space Agency/AP
This Chandra image of M83, a spiral galaxy about 15 million light-years from Earth, is one of the deepest X-ray observations ever made of a supernova from a spiral galaxy beyond our own. This full-field view of the spiral galaxy, released July 29, 2013, shows the low, medium, and high-energy X-rays observed by Chandra in red, green, and blue, respectively. NASA/CXC/STScI/K.Long et al., Optical: NASA/STScI/Reuters
The NASA/ESA Hubble Space Telescope captured this image, released in 2011, of dwarf irregular galaxy Holmberg II. The galaxy is dominated by huge bubbles of glowing gas, which are sites of ongoing star formation. As high-mass stars form in dense regions of gas and dust, they expel strong stellar winds that blow away surrounding material. The cavities are also blown clear of gas by the shock waves produced in supernovae, violent explosions that mark the end of the lives of massive stars. NASA/AP
NASA’s Chandra X-ray Observatory reveals a massive cloud of multimillion-degree gas in a galaxy about 60 million light-years from Earth, in this photo released Aug. 14, 2013. The hot gas cloud is probably caused by a collision between a dwarf galaxy and a much larger galaxy called NGC 1232, according to NASA. NASA/CXC/Huntingdon Institute for X-ray Astronomy/G. Garmire/Reuters
This 2006 photo taken by the Hubble Space Telescope shows a cluster of diverse galaxies. A study led by a Yale University astronomer looks at elliptical galaxies, such as the bright one in the top middle of this photograph, and finds they have many more stars than initially thought. That means the universe may have three times more stars than astronomers previously figured. The bright part of the Hubble photo shows a cluster of galaxies 450 million light-years away. NASA/AP
This 2009 image from the Spitzer Space Telescope is of a galaxy called NGC-1097, located 50 million light-years away. It is spiral-shaped like our Milky Way. The 'eye' at its center is actually a monstrous black hole surrounded by a ring of stars. In this color-coded infrared view, the area around the invisible black hole is blue and the ring of stars is white. The black hole feeds off of gas and dust – and the occasional star. The galaxy's red spiral arms and the swirling spokes between the arms show dust heated by newborn stars. Older populations of stars scattered throughout the galaxy are blue. The fuzzy blue dot to the left, which appears to fit snugly between the arms, is a companion galaxy. NASA/AP
In the direction of the constellation Canis Major, two spiral galaxies pass by each other like majestic ships in the night. The near-collision has been caught in images taken by NASA's Hubble Space Telescope and its Wide Field Planetary Camera 2. Hubble Heritage Team (STScI)/NASA
This image released March 21, 2013 shows the afterglow of the big bang, the cosmic microwave background as detected by the European Space Agency's Planck space probe. The radiation was imprinted on the sky when the universe was 370,000 years old. It shows tiny temperature fluctuations that correspond to regions of slightly different densities, representing the seeds of all future structure: the stars and galaxies of today. ESA/Planck Collaboration/NASA/AP
The star collections known as galaxies formed much sooner in the early universe than previously estimated, according to an analysis of data from the Hubble Space Telescope. Galaxies were well established within 2.5 billion years of the big bang.
European Space Agency/NASA/ESA Hubble Space Telescope/Handout via Reuters
Galaxies appear to have matured much sooner in the early universe than previously estimated, adding intriguing twists to the history that astronomers are compiling of the growth and evolution of these vast collections of stars.