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The Gum Nebula Credit & Copyright: Axel Mellinger Explanation: Named for Australian astronomer Colin Stanley Gum (1924-1960), The Gum Nebula is so large and close it is actually hard to see. In fact, we are only about 450 light-years from the front edge and 1,500 light-years from the back edge of this cosmic cloud of glowing hydrogen gas. Covered in this 41 degree-wide mosaic of H-alpha images, the faint emission region is otherwise easy to lose against the background of Milky Way stars. The complex nebula is thought to be a supernova remnant over a million years old, sprawling across...

The Colliding Spiral Galaxies of Arp 274 Credit: NASA, ESA, M. Livio (STScI) and the Hubble Heritage Team (STScI/AURA) Explanation: Two galaxies are squaring off in Virgo and here are the latest pictures. When two galaxies collide, the stars that compose them usually do not. This is because galaxies are mostly empty space and, however bright, stars only take up only a small fraction of that space. But during the collision, one galaxy can rip the other apart gravitationally, and dust and gas common to both galaxies does collide. If the two galaxies merge, black holes that likely resided in...

Tycho's Supernova Remnant Credit: X-ray: NASA/CXC/SAO; Infrared: NASA/JPL-Caltech; Optical: MPIA, Calar Alto, O. Krause et al. Explanation: What star created this huge puffball? Pictured above is the best multi-wavelength image yet of Tycho's supernova remnant, the result of a stellar explosion first recorded over 400 years ago by the famous astronomer Tycho Brahe. The above image is a composite of an X-ray image taken by the orbiting Chandra X-ray Observatory, an infrared image taken by the orbiting Spitzer Space Telescope, and an optical image taken by the 3.5-meter Calar Alto telescope located in southern Spain. The expanding gas cloud is...

Eye of God photographed in Space 26/02/2009 Eye of God... this breathtaking image of the Helix nebula, giant rings of gas blown off a dying star 700 light years from the Sun, was captured with a special camera at an observatory in Chile. What happens if it blinks...

Fox Fur, a Unicorn, and a Christmas Tree Credit & Copyright: R Jay Gabany Explanation: Clouds of glowing hydrogen gas fill this colorful skyscape in the faint but fanciful constellation Monoceros, the Unicorn. A star forming region cataloged as NGC 2264, the complex jumble of cosmic gas and dust is about 2,700 light-years distant and mixes reddish emission nebulae excited by energetic light from newborn stars with dark interstellar dust clouds. Where the otherwise obscuring dust clouds lie close to the hot, young stars they also reflect starlight, forming blue reflection nebulae. The wide mosaic spans about 3/4 degree...

The Dumbbells Credit & Copyright: Daniel López, IAC Explanation: These two nebulae are cataloged as M27 (left) and M76, popularly known as The Dumbbell and the Little Dumbbell. Not intended to indicate substandard mental prowess, their popular names refer to their similar, dumbbell or hourglass shapes. Both are planetary nebulae, gaseous shrouds cast off by dying sunlike stars, and are similar in physical size, at a light-year or so across. In each panel, the images were made at the same scale, so the apparent size difference is mostly because one is closer. Distance estimates suggest 1,200 light-years for the Dumbbell...

Massive Stars in Open Cluster Pismis 24 Credit: NASA, ESA and J. M. Apellániz (IAA, Spain) Explanation: How massive can a normal star be? Estimates made from distance, brightness and standard solar models had given one star in the open cluster Pismis 24 over 200 times the mass of our Sun, making it a record holder. This star is the brightest object located just above the gas front in the above image. Close inspection of images taken recently with the Hubble Space Telescope, however, have shown that Pismis 24-1 derives its brilliant luminosity not from a single star but from...

Great Orion Nebulae Credit & Copyright: Tony Hallas Explanation: The Great Nebula in Orion, also known as M42, is one of the most famous nebulae in the sky. The star forming region's glowing gas clouds and hot young stars are on the right in this sharp and colorful two frame mosaic that includes the smaller nebula M43 near center and dusty, bluish reflection nebulae NGC 1977 and friends on the left. Located at the edge of an otherwise invisible giant molecular cloud complex, these eye-catching nebulae represent only a small fraction of this galactic neighborhood's wealth of interstellar material. Within...

Young Stars of NGC 346 Credit: Antonella Nota (ESA/STScI) et al., ESA, NASA Explanation: The massive stars of NGC 346 are short lived, but very energetic. The star cluster is embedded in the largest star forming region in the Small Magellanic Cloud, some 210,000 light-years distant. Their winds and radiation sweep out an interstellar cavern in the gas and dust cloud about 200 light-years across, triggering star formation and sculpting the region's dense inner edge. Cataloged as N66, the star forming region also appears to contain a large population of infant stars. A mere 3 to 5 million years old...

M83: The Thousand-Ruby Galaxy Color Composite: Davide De Martin (Skyfactory)Credit: European Southern Observatory Science Archive Explanation: Big, bright, and beautiful, spiral galaxy M83 lies a mere twelve million light-years away, near the southeastern tip of the very long constellation Hydra. Prominent spiral arms traced by dark dust lanes and blue star clusters lend this galaxy its popular name of the Southern Pinwheel. But reddish star forming regions that dot the sweeping arms highlighted in this sparkling color composite also suggest another nickname, The Thousand-Ruby Galaxy. About 40,000 light-years across, M83 is a member of a group of galaxies that...

CG4: A Ruptured Cometary Globule Credit & Copyright: Mike Sidonio Explanation: Can a gas cloud grab a galaxy? It's not even close. The "claw" of this odd looking "creature" in the above photo is a gas cloud known as a cometary globule. This globule, however, has ruptured. Cometary globules are typically characterized by dusty heads and elongated tails. These features cause cometary globules to have visual similarities to comets, but in reality they are very much different. Globules are frequently the birthplaces of stars, and many show very young stars in their heads. The reason for the rupture in the...

NGC 6960: The Witch's Broom Nebula Credit & Copyright: Adam Block, Mount Lemmon SkyCenter, Univ. Arizona Explanation: Ten thousand years ago, before the dawn of recorded human history, a new light must suddenly have appeared in the night sky and faded after a few weeks. Today we know this light was an exploding star and record the colorful expanding cloud as the Veil Nebula. Pictured above is the west end of the Veil Nebula known technically as NGC 6960 but less formally as the Witch's Broom Nebula. The expanding debris cloud gains its colors by sweeping up and exciting existing...

SN 1006 Supernova Remnant Credit: X-ray - NASA/CXC/Rutgers/G.Cassam-Chenai, J.Hughes et al.; Radio - NRAO/AUI/NSF/GBT/VLA/ Dyer, Maddalena & Cornwell; Optical - Middlebury College/F.Winkler, NOAO/AURA/NSF/CTIO Schmidt & DSS Explanation: A new star, likely the brightest supernova in recorded human history, lit up planet Earth's sky in the year 1006 AD. The expanding debris cloud from the stellar explosion, found in the southerly constellation of Lupus, still puts on a cosmic light show across the electromagnetic spectrum. In fact, this composite view includes X-ray data in blue from the Chandra Observatory, optical data in yellowish hues, and radio image data in red....

In the Center of the Trifid Nebula Credit & Copyright: Daniel Lopez (Observatorio del Teide) Explanation: Clouds of glowing gas mingle with dust lanes in the Trifid Nebula, a star forming region toward the constellation of Sagittarius. In the center, the three prominent dust lanes that give the Trifid its name all come together. Mountains of opaque dust appear on the right, while other dark filaments of dust are visible threaded throughout the nebula. A single massive star visible near the center causes much of the Trifid's glow. The Trifid, also known as M20, is only about 300,000 years old,...

A Shocking Surprise in Stephan's Quintet This false-color composite image of the Stephan's Quintet galaxy cluster clearly shows one of the largest shock waves ever seen (green arc), produced by one galaxy falling toward another at over a million miles per hour. It is made up of data from NASA's Spitzer Space Telescope and a ground-based telescope in Spain. Four of the five galaxies in this image are involved in a violent collision, which has already stripped most of the hydrogen gas from the interiors of the galaxies. The centers of the galaxies appear as bright yellow-pink knots inside...

Young Star Cluster Westerlund 2 Credit: X-ray; Y.Nazé, G.Rauw, J.Manfroid (Université de Liège), CXC, NASA Infrared; E.Churchwell (University of Wisconsin), JPL, Caltech, NASA Explanation: Dusty stellar nursery RCW 49 surrounds young star cluster Westerlund 2 in this remarkable composite skyscape from beyond the visible spectrum of light. Infrared data from the Spitzer Space Telescope is shown in black and white, complimenting the Chandra X-ray image data (in false color) of the hot energetic stars within the cluster's central region. Looking toward the grand southern constellation Centaurus, both views reveal stars and structures hidden from optical telescopes by obscuring dust. Westerlund...

WASHINGTON - The latest act of senseless violence caught on tape is cosmic in scope: A black hole in a "death star galaxy" blasting a neighboring galaxy with a deadly jet of radiation and energy. A fleet of space and ground telescopes have captured images of this cosmic violence, which people have never witnessed before, according to a new study released Monday by NASA. "It's like a bully, a black-hole bully punching the nose of a passing galaxy," said astrophysicist Neil deGrasse Tyson, director of the Hayden Planetarium in New York, who wasn't involved in the research. But ultimately, this...

Did a giant impact create the two faces of Mars? 16:29 15 March 2007 NewScientist.com news service David Shiga, Houston Mars's northern hemisphere is lower in elevation – by about 5 kilometres – than its southern hemisphere (see image below). This coloured topographical map shows low elevations in blue and high elevations in yellow and red. The map is centred on a latitude of 55° north (Illustration: Mike Caplinger/MSSS) Mars's southern hemisphere is higher and more heavily cratered than the northern hemisphere, suggesting it is older terrain. The two low elevations (blue) in this map, which is centred on the...

The Cassini radar image (left) shows one of Titan's seas is larger than Lake Superior (right) Nasa's Cassini probe has found evidence for seas, probably filled with liquid hydrocarbons, at the high northern latitudes of Saturn's moon Titan.The dark features, detected by Cassini's radar, are much bigger than any lakes already detected on Titan. The largest is some 100,000 sq km (39,000 sq miles) - greater in extent than North America's Lake Superior. It covers a greater fraction of Titan than the proportion of Earth covered by the Black Sea. The Black Sea is the Earth's largest inland sea...

Rumors of a Strange Universe Credit: High-Z Supernova Search Team, HST, NASA Explanation: Eight years ago results were first presented indicating that most of the energy in our universe is not in stars or galaxies but is tied to space itself. In the language of cosmologists, a large cosmological constant is directly implied by new distant supernovae observations. Suggestions of a cosmological constant (lambda) are not new -- they have existed since the advent of modern relativistic cosmology. Such claims were not usually popular with astronomers, though, because lambda is so unlike known universe components, because lambda's value appeared...

In the Shadow of Saturn Credit: SSI, JPL, ESA, NASA Explanation: In the shadow of Saturn, unexpected wonders appear. The robotic Cassini spacecraft now orbiting Saturn recently drifted in giant planet's shadow for about 12 hours and looked back toward the eclipsed Sun. Cassini saw a view unlike any other. First, the night side of Saturn is seen to be partly lit by light reflected from its own majestic ring system. Next, the rings themselves appear dark when silhouetted against Saturn, but quite bright when viewed away from Saturn and slightly scattering sunlight, in the above exaggerated color image....

Photo shows the area in which Opportunity landed, the track outlined path it took over two years to negotiate 6 miles of desert to Victoria Crater Victoria Crater. The Mars-orbiting NASA satellite took a picture as it passed Victoria Crater and actually captured the Rover sitting on the edge of the crater.........A blow-up of the satellite photo showing Opportunity sitting on the crater's rim False color looking North to Cape Verde; great rock layers to explore. Looking Southeast across Duck Bay.

A new view of the Eagle Nebula, one of the two largest and sharpest images Hubble Space Telescope has ever taken, is released by NASA for Hubble's 15th anniversary April 25, 2005. The new Eagle Nebula image reveals a tall, dense tower of gas being sculpted by ultraviolet light from a group of massive, hot stars. During the 15 years Hubble has orbited the Earth, it has taken more than 700,000 photos of the cosmos.

Astronomy Picture of the Day Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. 2002 September 4 Halo of the Cat's Eye Credit: R. Corradi (Isaac Newton Group), D. Goncalves (Inst. Astrofisica de Canarias) Explanation: The Cat's Eye Nebula (NGC 6543) is one of the best known planetary nebulae in the sky. Its haunting symmetries are seen in the very central region of this stunning false-color picture, processed to reveal the enormous but extremely faint halo of gaseous material, over three light-years...

Astronomy Picture of the Day Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. 2002 July 25 NGC 1569: Heavy Elements from a Small Galaxy Credit: C.Martin (UCSB / Caltech), et al., CXC, NASA Explanation: For astronomers, elements other than hydrogen and helium are sometimes considered to be simply "heavy elements". It's understandable really, because even lumped all together heavy elements make up an exceedingly small fraction of the Universe. Still, heavy elements can profoundly influence galaxy and star formation ... not...

Astronomy Picture of the Day Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. 2002 July 12 Recycling Cassiopeia A Credit: R. Fesen (Dartmouth) and J. Morse (CASA, U. Colorado), Hubble Heritage Team, NASA Explanation: For billions of years, massive stars in our Milky Way Galaxy have lived spectacular lives. Collapsing from vast cosmic clouds, their nuclear furnaces ignite and create heavy elements in their cores. After a few million years, the enriched material is blasted back into interstellar space where star...

Astronomy Picture of the Day Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. 2002 June 26 In the Center of the Trifid Nebula Credit: GMOS, Gemini Observatory Explanation: Clouds of glowing gas mingle with lanes of dark dust in the Trifid Nebula, a star forming region toward the constellation of Sagittarius. In the center, the three huge dark dust lanes that give the Trifid its name all come together. Mountains of opaque dust appear on the lower left, while filaments of...

Astronomy Picture of the Day Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. 2002 May 31 In Chandor Chasma on Mars Credit: THEMIS, Mars Odyssey Team, JPL, NASA Explanation: Scroll right and dive into a spectacular canyon on Mars. This daytime infrared view, recently recorded by the THEMIS camera on board the orbiting Mars Odyssey spacecraft, covers a 30 by 175 kilometer swath running along the canyon floor. The north (left) end of the scene is poised at the edge of...

Astronomy Picture of the Day Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer. 2002 March 16 The Colorful Moon Credit: Galileo Project, JPL, NASA Explanation: Do you recognize the Earth's Moon when you see it? The crazy, patchwork appearance of the false-color image makes this almost full view of the Moon's familiar near side look very strange. The Sea of Tranquillity (Mare Tranquillitatis) is the bright blue area at right, the Ocean of Storms (Oceanus Procellarum) is the extensive blue and...