A different astronomy and space science related image is featured each day, along with a brief explanation.
http://antwrp.gsfc.nasa.gov/apod/astropix.html - Apr 25, 2014 12:59:07 AM - Nov 28, 2004 12:29:17 PM
Hubble's Messier 5 Image Credit: HSTESA,
"Beautiful Nebula discovered between the Balance [Libra] & the Serpent [Serpens] ..." begins the description of the 5th entry in 18th century astronomer Charles Messier's famous catalog of nebulae and star clusters. Though it appeared to Messier to be fuzzy and round and without stars, Messier 5 (M5) is now known to be a globular star cluster, 100,000 stars or more, bound by gravity and packed into a region around 165 light-years in diameter. It lies some 25,000 light-years away. Roaming the halo of our galaxy, globular star clusters are ancient members of the Milky Way. M5 is one of the oldest globulars, its stars estimated to be nearly 13 billion years old. The beautiful star cluster is a popular target for Earthbound telescopes. Of course, deployed in low Earth orbit on April 25, 1990, the Hubble Space Telescope has also captured its own stunning close-up view that spans about 20 light-years near the central region of M5. Even close to its dense core at the left, the cluster's aging red and blue giant stars and rejuvenatedblue stragglers stand out in yellow and blue hues in the sharp color image.
Lyrids in Southern Skies Image Credit & Copyright: Yuri BeletskyLas Campanas ObservatoryCarnegie Institution
Earth's annual Lyrid meteor shower peaked before dawn on April 22nd, as our fair planet plowed through dust from the tail of long-period comet Thatcher. Even in the dry and dark Atacama desert along Chile's Pacific coast, light from a last quarter Moon made the night sky bright, washing out fainter meteor streaks. But brighter Lyrid meteors still put on a show. Captured in this composited earth-and-sky view recorded during early morning hours, the meteors stream away from the shower's radiant near Vega, alpha star of the constellation Lyra. The radiant effect is due to perspective as the parallel meteor tracks appear to converge in the distance. Rich starfields and dust clouds of our own Milky Way galaxy stretch across the background
Gallery: Last week's lunar eclipse
Arp 81: 100 Million Years LaterHubble Legacy Archive; Processing - Martin Pugh
From planet Earth, we see this strongly distorted pair of galaxies, cataloged as Arp 81, as they were only about 100 million years after their close encounter. The havoc wreaked by their mutual gravitational interaction during the encounter is detailed in this color composite image showing twisted streams of gas and dust, a chaos of massive star formation, and a tidal tail stretching for 200 thousand light-years or so as it sweeps behind the cosmic wreckage. Also known as NGC 6622 (left) and NGC 6621, the galaxies are roughly equal in size but are destined to merge into one large galaxy in the distant future, making repeated approaches until they finally coalesce. Located in the constellation Draco, the galaxies are 280 million light-years away. Even more distant background galaxies can be spotted in this sharp, reprocessed, image from Hubble Legacy Archive data.
pixels in space
The El Gordo Massive Galaxy Cluster ESA, J. JeeUC Daviset al.
It is bigger than a bread box. In fact, it is much bigger than all bread boxes put together. Galaxy cluster ACT-CL J0102-4915 is one of the largest and most massive objects known. Dubbed "El Gordo", the seven billion light years (z = 0.87) distant galaxy cluster spans about seven million light years and holds the mass of a million billion Suns. The above image of El Gordo is a composite of a visible light image from the , an X-ray image from the Chandra Observatory showing the hot gas in pink, and a computer generated map showing the most probable distribution of dark matter in blue, computed from gravitational lens distortions of background galaxies. Almost all of the bright spots are galaxies. The blue dark matter distribution indicates that the cluster is in the middle stages of a collision between two large galaxy clusters. A careful inspection of the image will reveal a nearly vertical galaxy that appears unusually long. That galaxy is actually far in the background and has its image stretched by the gravitational lens action of the massive cluster.
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Massive Nearby Spiral Galaxy NGC 2841 Image Credit: Hubble, Subaru; Composition & Copyright: Robert Gendler
It is one of the more massive galaxies known. A mere 46 million light-years distant, spiral galaxy NGC 2841 can be found in the northern constellation of Ursa Major. This sharp view of the gorgeous island universe shows off a striking yellow nucleus and galactic disk. Dust lanes, small, pink star-forming regions, and young blue star clusters are embedded in the patchy, tightly woundspiral arms. In contrast, many other spirals exhibit grand, sweeping arms with large star-forming regions. NGC 2841 has a diameter of over 150,000 light-years, even larger than our own Milky Way and captured by this composite image merging exposures from the orbiting 2.4-meter Hubble Space Telescope and the ground-based 8.2-meter Subaru TelescopeX-ray images suggest that resulting winds and stellar explosions create plumes of hot gas extending into a halo around NGC 2841.
Ash and Lightning above an Icelandic Volcano Image Credit & Copyright: Sigurður Stefnisson
Why did a picturesque 2010 volcanic eruption in Iceland create so much ash? Although the large ash plume was not unparalleled in its abundance, its location was particularly noticeable because it drifted across such well-populated areas. The Eyjafjallajökull volcano in southern Iceland began erupting on 2010 March 20, with a second eruption starting under the center of a small glacier on 2010 April 14. Neither eruption was unusually powerful. The second eruption, however, melted a large amount of glacial ice which then cooled and fragmented lava into gritty glass particles that were carried up with the rising volcanic plume. Pictured above during the second eruption, lightning bolts illuminate ash pouring out of the Eyjafjallajökull volcano.
Earth-size Kepler-186fIllustration Credit:NASA AmesSETI Institute / JPL-Caltech, Discovery:Elisa V. Quintana, et al.
Planet Kepler-186f is the first known Earth-size planet to lie within the habitable zone of a star beyond the Sun. Discovered using data from the prolific planet-huntingKepler spacecraft, the distant world orbits its parent star, a cool, dim, M dwarf star about half the size and mass of the Sun, some 500 light-years away in the constellation Cygnus. M dwarfs are common, making up about 70 percent of the stars in our Milky Way galaxy. To be within the habitable zone, where surface temperatures allowing liquid water are possible, Kepler-186f orbits close, within 53 million kilometers (about the Mercury-Sun distance) of the M dwarf star, once every 130 days. Four other planets are known in the distant system. All four are only a little larger than Earth and in much closer orbits, also illustrated in the tantalizing artist's vision. While the size and orbit of Kepler-186f are known, its mass and composition are not, and can't be determined by Kepler's transit technique. Still, models suggest that it could be rocky and have an atmosphere, making it potentially the most Earth-like exoplanet discovered so far ...
Red Moon, Green Beam Dan Long (Apache Point Observatory) - Courtesy: Tom Murphy (UC San Diego)
This is not a scene from a sci-fi special effects movie. The green beam of light and red lunar disk are real enough, captured in the early morning hours of April 15. Of course, the reddened lunar disk is easy to explain as the image was taken during this week's . Immersed in shadow, the eclipsed Moon reflects the dimmed reddened light of all the sunsets and sunrises filtering around the edges of planet Earth, seen in silhouette from a lunar perspective. But the green beam of light really is a laser. Shot from the 3.5-meter telescope at Apache Point Observatory in southern New Mexico, the beam's path is revealed as Earth's atmosphere scatters some of the intense laser light. The laser's target is the Apollo 15 retroreflector, left on the Moon by the astronauts in 1971. By determining the light travel time delay of the returning laser pulse, the experimental team from UC San Diego is able to measure the Earth-Moon distance to millimeter precision and provide a test of General Relativity, Einstein's theory of gravity. Conducting the lunar laser ranging experiment during a total eclipse uses the Earth like a cosmic light switch. With direct sunlight blocked, the reflector's performance is improved over performance when illuminated by sunlight during a normal Full Moon, an effect fondly known as The Full Moon Curse
in the zone
Waterton Lake Eclipse