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Keyword: astronomy

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  • Astronomy Picture of the Day -- A Space Shuttle on the Streets of Los Angeles

    10/22/2012 3:08:19 AM PDT · by SunkenCiv · 7 replies
    NASA ^ | October 22, 2012 | (see photo credit)
    Explanation: Was that the space shuttle that just went by? Garnering attention that could make even a movie star blush, thousands of people watched in awe as a quintessential icon of the space age was towed through the streets of Los Angeles. After landing at LAX airport late last month, the shuttle Endeavour was carefully loaded onto rolling trailers and maneuvered down roads and across bridges to the California Science Center, 20 kilometers away. To many, there was a majesty to the voyage that was beyond description, inspiring people to line the LA streets and wait at windows and balconies...
  • Astronomy Picture of the Day -- The Horsehead Nebula

    10/22/2012 3:05:53 AM PDT · by SunkenCiv · 3 replies
    NASA ^ | October 21, 2012 | (see photo credit)
    Explanation: One of the most identifiable nebulae in the sky, the Horsehead Nebula in Orion, is part of a large, dark, molecular cloud. Also known as Barnard 33, the unusual shape was first discovered on a photographic plate in the late 1800s. The red glow originates from hydrogen gas predominantly behind the nebula, ionized by the nearby bright star Sigma Orionis. The darkness of the Horsehead is caused mostly by thick dust, although the lower part of the Horsehead's neck casts a shadow to the left. Streams of gas leaving the nebula are funneled by a strong magnetic field. Bright...
  • Astronomy Picture of the Day -- Zodiacal Light and Milky Way

    10/21/2012 6:20:33 AM PDT · by SunkenCiv · 9 replies
    NASA ^ | October 20, 2012 | (see photo credit)
    Explanation: Ghostly apparitions of two fundamental planes in planet Earth's sky span this October all-sky view. The scene was captured from a lakeside campsite under dark skies in northern Maine, USA. In it, the plane of our Milky Way Galaxy arcs above faint airglow along the horizon. Zodiacal light, a band of dust scattering sunlight along the solar system's ecliptic plane, stretches almost horizontally across the wide field and intersects the Milky way near a point marked by bright planet Jupiter. Right of Jupiter, past the Pleiades star cluster, is the brightening of the Zodiacal band known as the Gegenschein,...
  • Astronomy Picture of the Day -- Merging NGC 2623

    10/19/2012 5:29:22 PM PDT · by SunkenCiv · 25 replies
    NASA ^ | October 19, 2012 | (see photo credit)
    Explanation: NGC 2623 is really two galaxies that are becoming one. Seen to be in the final stages of a titanic galaxy merger, the pair lies some 300 million light-years distant toward the constellation Cancer. The violent encounter between two galaxies that may have been similar to the Milky Way has produced widespread star formation near a luminous core and along eye-catching tidal tails. Filled with dust, gas, and young blue star clusters, the opposing tidal tails extend well over 50,000 light-years from the merged nucleus. Likely triggered by the merger, accretion by a supermassive black hole drives activity within...
  • Astronomy Picture of the Day -- A View from Next Door

    10/18/2012 8:09:48 PM PDT · by SunkenCiv · 16 replies
    NASA ^ | October 18, 2012 | (see photo credit)
    Explanation: Located just next door, Alpha Centauri is the closest star system to the Sun. A view from our interstellar neighbor a mere 4.3 light-years away is shown in this illustration. The Sun is at the upper right, a bright star against the background of the Milky Way. The crescent in the foreground is an artist's rendering of a planet now reported orbiting Alpha Centauri B, making it the closest known exoplanet. Discovered by astronomer Xavier Dumusque et al. using the planet hunting HARPS instrument to measure minute shifts in the star's spectrum for more than four years, the planet...
  • Planet Found in Nearest Star System to Earth

    10/17/2012 4:46:35 PM PDT · by VanShuyten · 19 replies
    European astronomers have discovered a planet with about the mass of the Earth orbiting a star in the Alpha Centauri system — the nearest to Earth. It is also the lightest exoplanet ever discovered around a star like the Sun. The planet was detected using the HARPS instrument on the 3.6-metre telescope at ESO’s La Silla Observatory in Chile. The results will appear online in the journal Nature on 17 October 2012.
  • Astronomy Picture of the Day -- Aurora Over White Dome Geyser

    10/17/2012 3:36:39 AM PDT · by SunkenCiv · 3 replies
    NASA ^ | October 17, 2012 | (see photo credit)
    Explanation: Sometimes both heaven and Earth erupt. Colorful aurorae erupted unexpectedly earlier this month, with green aurora appearing near the horizon and brilliant bands of red aurora blooming high overhead. A bright Moon lit the foreground of this picturesque scene, while familiar stars could be seen far in the distance. With planning, the careful astrophotographer shot this image mosaic in the field of White Dome Geyser in Yellowstone National Park in the western USA. Sure enough, just after midnight, White Dome erupted -- spraying a stream of water and vapor many meters into the air. Geyser water is heated to...
  • Astronomy Picture of the Day -- A Spiral Nebula Surrounding Star R Sculptoris

    10/16/2012 2:34:08 AM PDT · by SunkenCiv · 12 replies
    NASA ^ | October 16, 2012 | (see photo credit)
    Explanation: What's happening around that star? An unusual spiral structure has been discovered around the Milky Way star R Sculptoris, a red giant star located about 1,500 light years away toward the constellation of the Sculptor (Sculptoris). The star was observed with the new Atacama Large Millimeter/submillimeter Array (ALMA), the most powerful telescopic array observing near millimeter wavelengths, that part of the spectrum situated well beyond red light and between microwaves and radio waves. Data from ALMA observations was used to create a 3D visualization of the gas and dust immediately surrounding the star. A digital slice through this data...
  • Astronomy Picture of the Day -- Black Sun and Inverted Starfield

    10/15/2012 3:52:56 AM PDT · by SunkenCiv · 8 replies
    NASA ^ | October 15, 2012 | (see photo credit)
    Explanation: Does this strange dark ball look somehow familiar? If so, that might be because it is our Sun. In the above image, a detailed solar view was captured originally in a very specific color of red light, then rendered in black and white, and then color inverted. Once complete, the resulting image was added to a starfield, then also color inverted. Visible in the above image of the Sun are long light filaments, dark active regions, prominences peaking around the edge, and a moving carpet of hot gas. The surface of our Sun has become a particularly busy place...
  • Astronomy Picture of the Day -- The Hubble Extreme Deep Field

    10/14/2012 3:04:01 AM PDT · by SunkenCiv · 35 replies
    NASA ^ | October 14, 2012 | (see photo credit)
    Explanation: What did the first galaxies look like? To help answer this question, the Hubble Space Telescope has just finished taking the eXtreme Deep Field (XDF), the deepest image of the universe ever taken in visible light. Pictured above, the XDF shows a sampling of some of the oldest galaxies ever seen, galaxies that formed just after the dark ages, 13 billion years ago, when the universe was only a few percent of its present age. The Hubble Space Telescope's ACS camera and the infrared channel of the WFPC3 camera took the image. Combining efforts spread over 10 years, the...
  • Astronomy Picture of the Day -- Galaxies, Stars, and Dust

    10/12/2012 9:40:32 PM PDT · by SunkenCiv · 10 replies
    NASA ^ | October 13, 2012 | (see photo credit)
    Explanation: Spiky stars and spooky shapes abound in this deep cosmic skyscape. Its well-composed field of view covers about 2 Full Moons on the sky toward the constellation Pegasus. Of course the brighter stars show diffraction spikes, the commonly seen effect of internal supports in reflecting telescopes, and lie well within our own Milky Way galaxy. The faint but pervasive clouds of interstellar dust ride above the galactic plane and dimly reflect the Milky Way's combined starlight. Known as high latitude cirrus or integrated flux nebulae they are associated with molecular clouds. In this case, the diffuse cloud cataloged as...
  • Astronomy Picture of the Day -- Pan-STARRS and Nebulae

    10/12/2012 3:08:20 AM PDT · by SunkenCiv · 2 replies
    NASA ^ | October 12, 2012 | (see photo credit)
    Explanation: A single image from the world's most powerful survey instrument captured this spectacular skyview. Looking toward Sagittarius, the scene spans nearly 3 degrees or six times the width of the Full Moon. At bottom, upper right, and lower left it covers the Lagoon Nebula (M8), the Trifid Nebula (M20), and NGC 6559, in the crowded, dusty starfields of the central Milky Way. The adopted color scheme shows dust reddened starlight in red hues and normally red emission from hydrogen atoms in green. Built and operated by the Pan-STARRS project, the instrument features a 1.4 gigapixel (billion pixel) digital camera...
  • Astronomy Picture of the Day -- Aurorae over Planet Earth

    10/11/2012 4:14:24 AM PDT · by SunkenCiv · 8 replies
    NASA ^ | October 11, 2012 | (see photo credit)
    Explanation: North America at night is easy to recognize in this view of our fair planet from orbit, acquired by the Suomi-NPP satellite on October 8. The spectacular waves of visible light emission rolling above the Canadian provinces of Quebec and Ontario in the upper half of the frame are the Aurora Borealis or northern lights. Encircling the poles and extending to lower latitudes, impressive aurorae seen during the past few days are due to strong geomagnetic storms. The storms were triggered by a solar coronal mass ejection on October 4/5, impacting Earth's magnetosphere some three days later. The curtains...
  • Astronomy Picture of the Day -- Nauset Light Star Trails

    10/10/2012 6:01:53 PM PDT · by SunkenCiv · 8 replies
    NASA ^ | October 10, 2012 | (see photo credit)
    Explanation: In myth, Atlas holds up the heavens, but in this scene they seem to pivot around a lighthouse beacon. Photographed with a camera fixed to a tripod, the well-planned 30 minute exposure records star trails in the northern sky, reflecting the daily rotation of planet Earth. Hidden behind the top of the prominent Nauset Lighthouse on Cape Cod, Massachusetts, USA, the North Celestial Pole is at the center of all the star trail arcs. Making a complete circle, 360 degrees, in 24 hours, the star trail arcs cover 15 degrees each hour or 7.5 degrees in thirty minutes. Foreground...
  • Mystery Behind Supernova SN 1006 Solved?

    10/09/2012 3:49:42 PM PDT · by SunkenCiv · 8 replies
    Discovery News ^ | Monday, October 8, 2012 | Jennifer Ouellette
    Historical accounts from all over the world describe a spectacularly bright "guest star" in the night sky during the spring of 1006 -- what we now know as a supernova (SN 1006). Now astronomers think they have pinpointed the probable cause of that massive explosion, one thousand years later: a merging of two white dwarf stars. SN 1006 made quite a splash on its debut around May 1, 1006, in the constellation Lupus (the Wolf) just south of Scorpio. The critics raved! Monks in a Benedictine abbey in Switzerland marveled at the star's brightness, and commented on the variability of...
  • Astronomy Picture of the Day -- Simeis 147: Supernova Remnant

    10/09/2012 3:52:11 AM PDT · by SunkenCiv · 5 replies
    NASA ^ | October 09, 2012 | (see photo credit)
    Explanation: It's easy to get lost following the intricate filaments in this detailed mosaic image of faint supernova remnant Simeis 147 (S147). Also cataloged as Sh2-240, it covers nearly 3 degrees or 6 full moons on the sky. That's about 150 light-years at the stellar debris cloud's estimated distance of 3,000 light-years. Anchoring the frame at the right, bright star Elnath (Beta Tauri) is seen towards the boundary of the constellations Taurus and Auriga, almost exactly opposite the galactic center in planet Earth's sky. This sharp composite includes image data taken through a narrow-band filter to highlight emission from hydrogen...
  • Astronomy Picture of the Day -- Spherical Planetary Nebula Abell 39

    10/08/2012 8:17:39 PM PDT · by SunkenCiv · 8 replies
    NASA ^ | October 08, 2012 | (see photo credit)
    Explanation: Ghostly in appearance, Abell 39 is a remarkably simple, spherical nebula about five light-years across. Well within our own Milky Way galaxy, the cosmic sphere is roughly 7,000 light-years distant toward the constellation Hercules. Abell 39 is a planetary nebula, formed as a once sun-like star's outer atmosphere was expelled over a period of thousands of years. Still visible, the nebula's central star is evolving into a hot white dwarf. Although faint, the nebula's simple geometry has proven to be a boon to astronomers exploring the chemical abundances and life cycles of stars. In this deep image recorded under...
  • Astronomy Picture of the Day -- The Same Color Illusion

    10/06/2012 9:43:54 PM PDT · by SunkenCiv · 19 replies
    NASA ^ | October 07, 2012 | (see photo credit)
    Explanation: Are square A and B the same color? They are! To verify this, either run your cursor over the image or click here to see them connected. The above illusion, called the same color illusion, illustrates that purely human observations in science may be ambiguous or inaccurate. Even such a seemingly direct perception as relative color. Similar illusions exist on the sky, such as the size of the Moon near the horizon, or the apparent shapes of astronomical objects. The advent of automated, reproducible, measuring devices such as CCDs have made science in general and astronomy in particular less...
  • Astronomy Picture of the Day -- At the Heart of Orion

    10/06/2012 1:07:39 AM PDT · by SunkenCiv · 5 replies
    NASA ^ | October 06, 2012 | (see photo credit)
    Explanation: Near the center of this sharp cosmic portrait, at the heart of the Orion Nebula, are four hot, massive stars known as the Trapezium. Gathered within a region about 1.5 light-years in radius, they dominate the core of the dense Orion Nebula Star Cluster. Ultraviolet ionizing radiation from the Trapezium stars, mostly from the brightest star Theta 1 Orionis C powers the complex star forming region's entire visible glow. About three million years old, the Orion Nebula Cluster was even more compact in its younger years and a recent dynamical study indicates that runaway stellar collisions at an earlier...
  • Astronomy Picture of the Day -- Aurora and Fireball Over Norway

    10/05/2012 4:40:53 PM PDT · by SunkenCiv · 7 replies
    NASA ^ | October 05, 2012 | (see photo credit)
    Explanation: What's happening behind that mountain? A convergence of variable sky spectacles. One night in mid-September near Tromsø, Norway, high red aurora could be seen shimmering through lower green aurora in a way that created a striking and somewhat unusual violet glow. Suddenly, though, the sky flashed with the brightest fireball the astrophotographer had ever seen, as a small pebble from outer space violently crashed into the Earth's atmosphere. The glow illuminated the distant mountain peak known as Otertinden of the Lyngen Alps. The bright meteor, which coincidently disappeared behind the same mountain, was also reflected in the foreground Signalelva...
  • Astronomy Picture of the Day -- NGC 7293: The Helix Nebula

    10/05/2012 4:40:35 PM PDT · by SunkenCiv · 7 replies
    NASA ^ | October 04, 2012 | (see photo credit)
    Explanation: A mere seven hundred light years from Earth, in the constellation Aquarius, a sun-like star is dying. Its last few thousand years have produced the Helix Nebula (NGC 7293), a well studied and nearby example of a Planetary Nebula, typical of this final phase of stellar evolution. A total of 58 hours of exposure time have gone in to creating this deep view of the nebula. Accumulating narrow band data from emission lines of hydrogen atoms in red and oxygen atoms in blue-green hues, it shows remarkable details of the Helix's brighter inner region, about 3 light-years across, but...
  • Astronomy Picture of the Day -- Goat Aurora Over Greenland

    10/03/2012 3:19:15 AM PDT · by SunkenCiv · 21 replies
    NASA ^ | October 03, 2012 | (see photo credit)
    Explanation: Sometimes it's hard to believe what you see in the sky. During the Shelios Expedition to Greenland in late August, even veteran sky enthusiasts saw auroras so colorful, so fast changing, and so unusual in form that they could remember nothing like it. As the ever changing auroras evolved, huge shapes spread across the sky morphed from one familiar form into another, including what looked to be the head of a goat (shown above), the head of an elephant, a strange green-tailed comet, and fingers on a celestial hand. Even without the aurora, the sky would be notable for...
  • Astronomy Picture of the Day -- An Ancient Stream Bank on Mars

    10/02/2012 3:33:37 AM PDT · by SunkenCiv · 5 replies
    NASA ^ | October 02, 2012 | (see photo credit)
    Explanation: Fresh evidence of an ancient stream has been found on Mars. The robotic rover Curiosity has run across unusual surface features that carry a strong resemblance to stream banks on Earth. Visible in the above image, for example, is a small overhanging rock ledge that was quite possibly created by water erosion beneath. The texture of the ledge appears to be a sedimentary conglomerate, the dried remains of many smaller rocks stuck together. Beneath the ledge are numerous small pebbles, possibly made smooth by tumbling in and around the once-flowing stream. Pebbles in the streambed likely fell there as...
  • Astronomy Picture of the Day -- Introducing Comet ISON

    10/01/2012 3:46:01 AM PDT · by SunkenCiv · 6 replies
    NASA ^ | October 01, 2012 | (see photo credit)
    Explanation: Could this dim spot brighten into one of the brightest comets ever? It's possible. Alternatively, the comet could break up when it gets closer to the Sun, or brighten much more modestly. Sky enthusiasts the world over are all abuzz, though, from the more optimistic speculations -- that the newly discovered C/2012 S1 (ISON) could develop a spectacular tail or briefly approach the brightness of the full Moon toward the end of 2013. Comet ISON currently is very faint but is just visible at magnitude 18 in the above image. The comet, discovered just over a week ago from...
  • Astronomy Picture of the Day -- A Galaxy Collision in NGC 6745

    09/30/2012 4:03:09 PM PDT · by SunkenCiv · 19 replies
    NASA ^ | September 30, 2012 | (see photo credit)
    Explanation: Galaxies don't normally look like this. NGC 6745 actually shows the results of two galaxies that have been colliding for only hundreds of millions of years. Just off the above digitally sharpened photograph to the lower right is the smaller galaxy, moving away. The larger galaxy, pictured above, used to be a spiral galaxy but now is damaged and appears peculiar. Gravity has distorted the shapes of the galaxies. Although it is likely that no stars in the two galaxies directly collided, the gas, dust, and ambient magnetic fields do interact directly. In fact, a knot of gas pulled...
  • Astronomy Picture of the Day -- NGC 7023: The Iris Nebula

    09/29/2012 6:53:10 PM PDT · by SunkenCiv · 15 replies
    NASA ^ | September 29, 2012 | (see photo credit)
    Explanation: Like delicate cosmic petals, these clouds of interstellar dust and gas have blossomed 1,300 light-years away in the fertile star fields of the constellation Cepheus. Sometimes called the Iris Nebula and dutifully cataloged as NGC 7023 this is not the only nebula in the sky to evoke the imagery of flowers. Still, this remarkable image shows off the Iris Nebula's range of colors and symmetries in impressive detail. Within the Iris, dusty nebular material surrounds a hot, young star. The dominant color of the brighter reflection nebula is blue, characteristic of dust grains reflecting starlight. Central filaments of the...
  • New Comet Discovered—May Become "One of Brightest in History" (outshine the moon)

    09/28/2012 1:20:52 PM PDT · by NYer · 24 replies
    National Geographic ^ | September 27, 2012 | Andrew Fazekas
    Sky-watchers in Australia ogle comet Lovejoy late last year. If astronomers' early predictions hold true, the holidays next year may hold a glowing gift for stargazers—a superbright comet, just discovered streaking near Saturn.Even with powerful telescopes, comet 2012 S1 (ISON) is now just a faint glow in the constellation Cancer. But the ball of ice and rocks might become visible to the naked eye for a few months in late 2013 and early 2014—perhaps outshining the moon, astronomers say.The comet is already remarkably bright, given how far it is from the sun, astronomer Raminder Singh Samra said. What's more, 2012...
  • Astronomy Picture of the Day -- APOD: 2012 September 28 - Stars in a Dusty Sky

    09/28/2012 4:06:50 AM PDT · by SunkenCiv · 5 replies
    NASA ^ | September 28, 2012 | (see photo credit)
    Explanation: Bright star Markab anchors this dusty skyscape. At the top right corner of the frame, Markab itself marks a corner of an asterism known as the Great Square, found within the boundaries of the constellation Pegasus, the flying horse. The wide and deep telescopic view rides along for some 5 degrees or about 10 times the angular diameter of the Full Moon, with blue reflection nebulae scattered around the scene. And even though this line-of-sight looks away from the plane of our Milky Way galaxy, it covers a region known to be filled with nearby molecular clouds. The associated...
  • Astronomy Picture of the Day -- Stars and Dust Across Corona Australis

    09/27/2012 7:50:09 PM PDT · by SunkenCiv · 6 replies
    NASA ^ | September 27, 2012 | (see photo credit)
    Explanation: Cosmic dust clouds sprawl across a rich field of stars in this sweeping telescopic vista near the northern boundary of Corona Australis, the Southern Crown. Probably less than 500 light-years away and effectively blocking light from more distant, background stars in the Milky Way, the densest part of the dust cloud is about 8 light-years long. At its tip (upper right) is a group of lovely reflection nebulae cataloged as NGC 6726, 6727, 6729, and IC 4812. A characteristic blue color is produced as light from hot stars is reflected by the cosmic dust. The smaller yellowish nebula (NGC...
  • Newly spotted comet may outshine the full moon

    09/26/2012 6:29:10 PM PDT · by SunkenCiv · 89 replies
    New Scientist ^ | Tuesday, September 25, 2012 | Jeff Hecht
    Vitali Nevski and Artyom Novichonok, of the International Scientific Optical Network (ISON) in Russia, discovered comet C/2012 S1 (ISON) on 21 September via images taken with a 40-centimetre reflecting telescope. Other sky-watchers soon spotted it, and the International Astronomical Union's Minor Planet Center in Cambridge, Massachusetts, announced the find yesterday. From the combined observations, astronomers were able to trace the comet's recent path and find images of it dating back to late December 2011. From there they calculated a near-parabolic orbit that has comet ISON headed almost straight towards the sun. Astronomers at the Remanzacco Observatory in Italy think that...
  • Astronomy Picture of the Day -- A Space Shuttle Over Los Angeles

    09/25/2012 9:17:10 PM PDT · by SunkenCiv · 19 replies
    NASA ^ | September 26, 2012 | (see photo credit)
    Explanation: It's not every day that a space shuttle lands at LAX. Although this was a first for the major Los Angeles airport hub, it was a last for the space shuttle Endeavour, as it completed its tour of California skies and landed, albeit atop a 747, for the last time. During its last flight the iconic shuttle and its chase planes were photographed near several of California's own icons including the Golden Gate Bridge in San Francisco, the Hollywood Sign, and the skyline of Los Angeles. Previously, in May, the space shuttle Enterprise was captured passing behind several of...
  • Astronomy Picture of the Day -- Unusual Spheres on Mars

    09/24/2012 9:14:37 PM PDT · by SunkenCiv · 40 replies
    NASA ^ | September 25, 2012 | (see photo credit)
    Explanation: Why are these strange little spheres on Mars? The robotic rover Opportunity chanced across these unusually shaped beads earlier this month while exploring a place named Kirkwood near the rim of Mars' Endeavor Crater. The above image taken by Opportunity's Microscopic Imager shows that some ground near the rover is filled with these unusual spheres, each spanning only about 3 millimeters. At first glance, the sometimes-fractured balls appear similar to the small rocks dubbed blueberries seen by Opportunity eight years ago, but these spheres are densely compacted and have little iron content. Although it is thought that these orbs...
  • Astronomy Picture of the Day -- NGC 2736: The Pencil Nebula

    09/24/2012 6:52:23 PM PDT · by SunkenCiv · 9 replies
    NASA ^ | September 24, 2012 | (see photo credit)
    Explanation: This shock wave plows through space at over 500,000 kilometers per hour. Moving toward to bottom of this beautifully detailed color composite, the thin, braided filaments are actually long ripples in a sheet of glowing gas seen almost edge on. Cataloged as NGC 2736, its narrow appearance suggests its popular name, the Pencil Nebula. About 5 light-years long and a mere 800 light-years away, the Pencil Nebula is only a small part of the Vela supernova remnant. The Vela remnant itself is around 100 light-years in diameter and is the expanding debris cloud of a star that was seen...
  • Astronomy Picture of the Day -- Equinox: The Sun from Solstice to Solstice

    09/22/2012 9:16:55 PM PDT · by SunkenCiv · 17 replies
    NASA ^ | September 23, 2012 | (see photo credit)
    Explanation: Yesterday was an equinox, a date when day and night are equal. Today, and every day until the next equinox, the night will be longer than the day in Earth's northern hemisphere, and the day will be longer than the night in Earth's southern hemisphere. An equinox occurs midway between the two solstices, when the days and nights are the least equal. The picture is a composite of hourly images taken of the Sun above Bursa, Turkey on key days from solstice to equinox to solstice. The bottom Sun band was taken during the winter solstice in 2007 December,...
  • Astronomy Picture of the Day -- Austrian Analemma

    09/22/2012 8:57:01 PM PDT · by SunkenCiv · 11 replies
    NASA ^ | September 22, 2012 | (see photo credit)
    Explanation: Today, the Sun crosses the celestial equator heading south at 14:49 Universal Time. An equinox (equal night), this astronomical event marks the first day of autumn in the northern hemisphere and spring in the south. With the Sun on the celestial equator, Earth dwellers will experience nearly 12 hours of daylight and 12 hours of darkness. To celebrate, consider this careful record of the Sun's yearly journey through southern Austrian skies. The scene is composed of images made at the same time each day, capturing the Sun's position on dates from September 29, 2011 through September 9, 2012. The...
  • Astronomy Picture of the Day -- September's Aurora

    09/21/2012 3:29:42 PM PDT · by SunkenCiv · 8 replies
    NASA ^ | September 21, 2012 | (see photo credit)
    Explanation: September's equinox arrives tomorrow as the Sun crosses the celestial equator heading south. The event marks the astronomical beginning of spring in the southern hemisphere and autumn in the north. And though the connection is still puzzling, the equinox seasons bring an increase in geomagnetic storms. So as northern nights grow longer, the equinox also heralds the arrival of a good season for aurora hunters. Recorded on September 20, these colorful northern lights were captured with camera and wide-angle lens near the Norwegian Sea coast outside Tromsø in Northern Norway. Shining at altitudes of 100 kilometers or so, the...
  • Astronomy Picture of the Day -- Sunrise Analemma (with a little extra)

    09/20/2012 3:46:22 AM PDT · by SunkenCiv · 11 replies
    NASA ^ | September 20, 2012 | (see photo credit)
    Explanation: An analemma is that figure-8 curve that you get when you mark the position of the Sun at the same time each day throughout planet Earth's year. In this case, 17 individual images taken at 0231 UT on dates between April 2 and September 16 follow half the analemma curve, looking east toward the rising sun and the Caspian sea from the boardwalk in the port city of Baku, Azerbaijan. With the sun nearest the horizon, those dates almost span the period between the 2012 equinoxes on March 20 and September 22. The northern summer Solstice on June 20...
  • Astronomy Picture of the Day -- Leaving Vesta

    09/19/2012 6:23:23 PM PDT · by SunkenCiv · 14 replies
    NASA ^ | September 19, 2012 | (see photo credit)
    Explanation: Next stop: Ceres. Last week the robotic Dawn spacecraft ended its year-long mission to asteroid Vesta, becoming the first spacecraft ever to visit this far off world located between Mars and Jupiter, in the Solar System's main asteroid belt. Many of the best images taken by Dawn at Vesta have been compiled into the above encompassing view. Vesta shows evidence of being a leftover from the early years of our Solar System, a building block for rocky planets like Earth. Vesta's ancient surface shows heavy cratering and long troughs likely created by huge impacts. The minor planet's low gravity...
  • Astronomy Picture of the Day -- Orbiting Astronaut Self-Portrait

    09/18/2012 3:51:36 PM PDT · by SunkenCiv · 12 replies
    NASA ^ | September 18, 2012 | (see photo credit)
    Explanation: Is it art? Earlier this month, space station astronaut Aki Hoshide (Japan) recorded this striking image while helping to augment the capabilities of the Earth-orbiting International Space Station (ISS). Visible in this outworldly assemblage is the Sun, the Earth, two portions of a robotic arm, an astronaut's spacesuit, the deep darkness of space, and the unusual camera taking the picture. This image joins other historic -- and possibly artistic -- self-portraits taken previously in space. The Expedition 32 mission ended yesterday when an attached capsule undocked with the ISS and returned some of the crew to Earth.
  • Astronomy Picture of the Day -- A Solar Filament Erupts [Wow!]

    09/17/2012 3:14:33 PM PDT · by SunkenCiv · 16 replies
    NASA ^ | September 17, 2012 | (see photo credit)
    Explanation: What's happened to our Sun? Nothing very unusual -- it just threw a filament. At the end of last month, a long standing solar filament suddenly erupted into space producing an energetic Coronal Mass Ejection (CME). The filament had been held up for days by the Sun's ever changing magnetic field and the timing of the eruption was unexpected. Watched closely by the Sun-orbiting Solar Dynamics Observatory, the resulting explosion shot electrons and ions into the Solar System, some of which arrived at Earth three days later and impacted Earth's magnetosphere, causing visible aurorae. Loops of plasma surrounding an...
  • Astronomy Picture of the Day -- Saturn: Bright Tethys and Ancient Rings

    09/16/2012 8:37:42 AM PDT · by SunkenCiv · 14 replies
    NASA ^ | September 16, 2012 | (see photo credit)
    Explanation: How old are Saturn's rings? No one is quite sure. One possibility is that the rings formed relatively recently in our Solar System's history, perhaps only about 100 million years ago when a moon-sized object broke up near Saturn. Evidence for a young ring age includes a basic stability analysis for rings, and the fact that the rings are so bright and relatively unaffected by numerous small dark meteor impacts. More recent evidence, however, raises the possibility that some of Saturn's rings may be billions of years old and so almost as old as Saturn itself. Inspection of images...
  • Astronomy Picture of the Day -- Ring Nebula Drawn

    09/15/2012 10:55:01 AM PDT · by SunkenCiv · 4 replies
    NASA ^ | September 15, 2012 | (see photo credit)
    Explanation: A planetary nebula with a simple symmetry familiar to telescopic sky gazers, the Ring Nebula (M57) is some 2,000 light-years away in the musical constellation Lyra. Hints of changing colors and subtle details are brought out in this remarkable sketch of the cosmic ring. The sketch was made with 800x magnification and excellent seeing conditions directly at the eyepiece of a 40 inch reflecting telescope. Colored pencils on white paper were used to create the original drawing, shown here digitally scanned with an inverted palette applied. About one light-year across, the nebula is composed of outer layers expelled from...
  • Astronomy Picture of the Day -- Elliptical M60, Spiral NGC 4647

    09/15/2012 10:53:41 AM PDT · by SunkenCiv · 9 replies
    NASA ^ | September 14, 2012 | (see photo credit)
    Explanation: Giant elliptical galaxy M60 and spiral galaxy NGC 4647 do look like an odd couple in this sharp cosmic portrait from the Hubble Space Telescope. But they are found in a region of space where galaxies tend to gather, on the eastern side of the nearby Virgo Galaxy Cluster. About 54 million light-years distant, bright M60's simpler egg-like shape is created by its randomly swarming older stars, while NGC 4647's young blue stars, gas and dust are organized into winding arms rotating in a flattened disk. Spiral NGC 4647 is estimated to be more distant than M60, some 63...
  • Astronomy Picture of the Day -- Cocoon Nebula Wide Field

    09/12/2012 9:18:50 PM PDT · by SunkenCiv · 5 replies
    NASA ^ | September 13, 2012 | (see photo credit)
    Explanation: In this crowded starfield covering over 2 degrees within the high flying constellation Cygnus, the eye is drawn to the Cocoon Nebula. A compact star forming region, the cosmic Cocoon punctuates a long trail of obscuring interstellar dust clouds. Cataloged as IC 5146, the nebula is nearly 15 light-years wide, located some 4,000 light years away. Like other star forming regions, it stands out in red, glowing, hydrogen gas excited by the young, hot stars and blue, dust-reflected starlight at the edge of an otherwise invisible molecular cloud. In fact, the bright star near the center of this nebula...
  • Astronomy Picture of the Day -- M7: Open Star Cluster in Scorpius

    09/12/2012 8:46:10 PM PDT · by SunkenCiv · 5 replies
    NASA ^ | September 12, 2012 | (see photo credit)
    Explanation: M7 is one of the most prominent open clusters of stars on the sky. The cluster, dominated by bright blue stars, can be seen with the naked eye in a dark sky in the tail of the constellation of the Scorpion (Scorpius). M7 contains about 100 stars in total, is about 200 million years old, spans 25 light-years across, and lies about 1000 light-years away. The above deep exposure was taken from Hakos Farm in Namibia. The M7 star cluster has been known since ancient times, being noted by Ptolemy in the year 130 AD. Also visible are a...
  • Astronomy Picture of the Day -- Milky Way Over the Bungle Bungles

    09/11/2012 4:21:41 PM PDT · by SunkenCiv · 7 replies
    NASA ^ | September 11, 2012 | (see photo credit)
    Explanation: Which part of this picture do you find more interesting -- the land or the sky? Advocates for the land might cite the beauty of the ancient domes of the Bungle Bungle Range in Western Australia. These picturesque domes appear as huge layered beehives and are made of sandstones and conglomerates deposited over 350 million years ago. Advocates for the sky might laud the beauty of the Milky Way's central band shown arching from horizon to horizon. The photogenic Milky Way band formed over 10 billion years ago and now includes many well-known nebulae and bright stars. Fortunately, you...
  • Astronomy Picture of the Day -- Curiosity on the Move

    09/10/2012 2:31:54 PM PDT · by SunkenCiv · 15 replies
    NASA ^ | September 10, 2012 | (see photo credit)
    Explanation: Curiosity is on the move across Mars -- but where is it going? The car-sized rover's path after 29 Martian days on the surface is shown on the above map. Curiosity is still almost 300 meters from its first major destination, though, a meeting of different types of terrain called Glenelg and visible on the image right. It may take Curiosity two months or so to get to Glenelg as it stops to inspect interesting rocks or landscape features along the way. The above image was taken about one week ago from high up by the HiRise camera onboard...
  • Astronomy Picture of the Day -- Wisps Surrounding the Horsehead Nebula

    09/08/2012 9:16:56 PM PDT · by SunkenCiv · 13 replies
    NASA ^ | September 09, 2012 | (see photo credit)
    Explanation: The famous Horsehead Nebula in Orion is not alone. A deep exposure shows that the dark familiar shaped indentation, visible just below center, is part of a vast complex of absorbing dust and glowing gas. To bring out details of the Horsehead's pasture, amateur astronomers at the Star Shadow Remote Observatory in New Mexico, USA fixed a small telescope on the region for over seven hours filtering out all but a very specific color of red light emitted by hydrogen. They then added the image to a full color frame taken over three hours. The resulting spectacular picture details...
  • Astronomy Picture of the Day -- Cosmic Rays at Voyager 1

    09/08/2012 9:16:52 PM PDT · by SunkenCiv · 13 replies
    NASA ^ | September 08, 2012 | (see photo credit)
    Explanation: Launched on a grand tour of the outer planets in 1977, by good fortune the twin Voyager spacecraft were also headed in the general direction of the Sun's motion relative to nearby stars. Thirty five years later, Voyager 1 appears to be nearing the boundary of the Sun's heliosphere and interstellar space. Of course the heliosphere is the realm of the Sun defined by the influence of the solar wind and the Sun's magnetic field. But how can you tell when your spacecraft crosses the boundary into interstellar space? One clue would be a sudden increase in the detection...
  • IU mathematician offers unified theory of dark matter, dark energy, altering Einstein field...

    09/08/2012 1:36:57 PM PDT · by neverdem · 21 replies
    Indiana University ^ | Sept. 6, 2012 | NA
    IU mathematician offers unified theory of dark matter, dark energy, altering Einstein field equations BLOOMINGTON, Ind. -- A pair of mathematicians -- one from Indiana University and the other from Sichuan University in China -- have proposed a unified theory of dark matter and dark energy that alters Einstein's equations describing the fundamentals of gravity. Shouhong Wang, a professor in the IU College of Arts and Sciences' Department of Mathematics, and Tian Ma, a professor at Sichuan University, suggest the law of energy and momentum conservation in spacetime is valid only when normal matter, dark matter and dark energy are...