Free Republic 1st Quarter Fundraising Target: $88,000 Receipts & Pledges to-date: $33,955
38%  
Woo hoo!! And the first 38% is in!! Thank you all very much!!

Keyword: apod

Brevity: Headers | « Text »
  • Astronomy Picture of the Day -- Close Encounter with M44

    01/29/2015 9:04:07 AM PST · by SunkenCiv · 4 replies
    NASA ^ | January 29, 2015 | (see photo credit)
    Explanation: On Monday, January 26, well-tracked asteroid 2004 BL86 made its closest approach, a mere 1.2 million kilometers from our fair planet. That's about 3.1 times the Earth-Moon distance or 4 light-seconds away. Moving quickly through Earth's night sky, it left this streak in a 40 minute long exposure on January 27 made from Piemonte, Italy. The remarkably pretty telescopic field of view includes M44, also known as the Beehive or Praesepe star cluster in Cancer. Of course, its close encounter with M44 is only an apparent one, with the cluster nearly along the same line-of-sight to the near-earth asteroid....
  • Astronomy Picture of the Day -- Comet Lovejoy in a Winter Sky

    01/29/2015 9:01:49 AM PST · by SunkenCiv · 6 replies
    NASA ^ | January 28, 2015 | (see photo credit)
    Explanation: Which of these night sky icons can you find in this beautiful and deep exposure of the northern winter sky? Skylights include the stars in Orion's belt, the Orion Nebula, the Pleiades star cluster, the bright stars Betelgeuse and Rigel, the California Nebula, Barnard's Loop, and Comet Lovejoy. The belt stars of Orion are nearly vertical in the central line between the horizon and the image center, with the lowest belt star obscured by the red glowing Flame Nebula. To the belt's left is the red arc of Barnard's Loop followed by the bright orange star Betelgeuse, while to...
  • Astronomy Picture of the Day -- Our Galaxy's Magnetic Field from Planck

    01/27/2015 8:31:28 AM PST · by SunkenCiv · 8 replies
    NASA ^ | January 27, 2015 | (see photo credit)
    Explanation: What does the magnetic field of our Galaxy look like? It has long been known that a modest magnetic field pervades our Milky Way Galaxy because it is seen to align small dust grains that scatter background light. Only recently, however, has the Sun-orbiting Planck satellite made a high-resolution map of this field. Color coded, the 30-degree wide map confirms, among other things, that the Galaxy's interstellar magnetism is strongest in the central disk. The rotation of charged gas around the Galactic center creates this magnetism, and it is hypothesized that viewed from the top, the Milky Way's magnetic...
  • Astronomy Picture of the Day -- The Milky Way over the Seven Strong Men Rock Formations

    01/27/2015 8:27:56 AM PST · by SunkenCiv · 7 replies
    NASA ^ | January 26, 2015 | (see photo credit)
    Explanation: You may have heard of the Seven Sisters in the sky, but have you heard about the Seven Strong Men on the ground? Located just west of the Ural Mountains, the unusual Manpupuner rock formations are one of the Seven Wonders of Russia. How these ancient 40-meter high pillars formed is yet unknown. The persistent photographer of this featured image battled rough terrain and uncooperative weather to capture these rugged stone towers in winter at night, being finally successful in February of last year. Utilizing the camera's time delay feature, the photographer holds a flashlight in the foreground near...
  • Astronomy Picture of the Day -- A Twisted Solar Eruptive Prominence

    01/25/2015 1:20:36 AM PST · by SunkenCiv · 9 replies
    NASA ^ | January 25, 2015 | (see photo credit)
    Explanation: Ten Earths could easily fit in the "claw" of this seemingly solar monster. The monster, actually a huge eruptive prominence, is seen moving out from our Sun in this condensed half-hour time-lapse sequence. This large prominence, though, is significant not only for its size, but its shape. The twisted figure eight shape indicates that a complex magnetic field threads through the emerging solar particles. Differential rotation of gas just inside the surface of the Sun might help account for the surface explosion. The five frame sequence was taken in early 2000 by the Sun-orbiting SOHO satellite. Although large prominences...
  • Astronomy Picture of the Day -- Light from Cygnus A

    01/24/2015 12:59:30 PM PST · by SunkenCiv · 11 replies
    NASA ^ | January 24, 2015 | (see photo credit)
    Explanation: Celebrating astronomy in this International Year of Light, the detailed image reveals spectacular active galaxy Cygnus A in light across the electromagnetic spectrum. Incorporating X-ray data ( blue) from the orbiting Chandra Observatory, Cygnus A is seen to be a prodigious source of high energy x-rays. But it is actually more famous at the low energy end of the electromagnetic spectrum. One of the brightest celestial sources visible to radio telescopes, at 600 million light-years distant Cygnus A is the closest powerful radio galaxy. Radio emission ( red) extends to either side along the same axis for nearly 300,000...
  • Astronomy Picture of the Day -- Interior View [space station]

    01/23/2015 3:57:31 AM PST · by SunkenCiv · 7 replies
    NASA ^ | January 23, 2015 | (see photo credit)
    Explanation: Some prefer windows, and these are the best available on board the International Space Station. Taken on January 4, this snapshot from inside the station's large, seven-window Cupola module also shows off a workstation for controlling Canadarm2. Used to grapple visiting cargo vehicles and assist astronauts during spacewalks, the robotic arm is just outside the window at the right. The Cupola itself is attached to the Earth-facing or nadir port of the station's Tranquility module, offering dynamic panoramas of our fair planet. Seen from the station's 90 minute long, 400 kilometer high orbit, Earth's bright limb is in view...
  • Astronomy Picture of the Day -- Launch to Lovejoy

    01/22/2015 11:42:36 AM PST · by SunkenCiv · 4 replies
    NASA ^ | January 22, 2015 | (see photo credit)
    Explanation: Blasting skyward an Atlas V rocket carrying a U.S. Navy satellite pierces a cloud bank in this starry night scene captured on January 20. On its way to orbit from Space Launch Complex 41, Cape Canaveral Air Force Station, planet Earth, the rocket streaks past brightest star Sirius, as seen from a dark beach at Canaveral National Seashore. Above the alpha star of Canis Major, Orion the Hunter strikes a pose familiar to northern winter skygazers. Above Orion is the V-shaped Hyades star cluster, head of Taurus the Bull, and farther still above Taurus it's easy to spot the...
  • Astronomy Picture of the Day -- The Complex Ion Tail of Comet Lovejoy

    01/21/2015 2:52:55 AM PST · by SunkenCiv · 6 replies
    NASA ^ | January 21, 2015 | (see photo credit)
    Explanation: What causes the structure in Comet Lovejoy's tail? Comet C/2014 Q2 (Lovejoy), which is currently at naked-eye brightness and near its brightest, has been showing an exquisitely detailed ion tail. As the name implies, the ion tail is made of ionized gas -- gas energized by ultraviolet light from the Sun and pushed outward by the solar wind. The solar wind is quite structured and sculpted by the Sun's complex and ever changing magnetic field. The effect of the variable solar wind combined with different gas jets venting from the comet's nucleus accounts for the tail's complex structure. Following...
  • Astronomy Picture of the Day -- Approaching Asteroid Ceres

    01/20/2015 5:55:25 AM PST · by SunkenCiv · 19 replies
    NASA ^ | January 20, 2015 | (see photo credit)
    Explanation: It is the largest asteroid in the asteroid belt -- what secrets does it hold? To find out, NASA has sent the robotic Dawn spacecraft to explore and map this cryptic 1,000-kilometer wide world: Ceres. Orbiting between Mars and Jupiter, Ceres is officially categorized as a dwarf planet but has never been imaged in detail. Featured here is a 20-frame video taken a week ago of Dawn's approach that now rivals even the best images of Ceres ever taken by the Hubble Space Telescope. The video shows enough surface definition to discern its 9-hour rotation period. On target to...
  • Astronomy Picture of the Day -- Infrared Orion from WISE

    01/18/2015 11:53:07 PM PST · by SunkenCiv · 20 replies
    NASA ^ | January 19, 2015 | (see photo credit)
    Explanation: The Great Nebula in Orion is an intriguing place. Visible to the unaided eye, it appears as a small fuzzy patch in the constellation of Orion. But this image, an illusory-color four-panel mosaic taken in different bands of infrared light with the Earth orbiting WISE observatory, shows the Orion Nebula to be a bustling neighborhood or recently formed stars, hot gas, and dark dust. The power behind much of the Orion Nebula (M42) is the stars of the Trapezium star cluster, seen near the center of the above wide field image. The orange glow surrounding the bright stars pictured...
  • Astronomy Picture of the Day -- The Galactic Core in Infrared

    01/18/2015 3:24:38 AM PST · by SunkenCiv · 14 replies
    NASA ^ | January 18, 2015 | (see photo credit)
    Explanation: What's happening at the center of our Milky Way Galaxy? To help find out, the orbiting Hubble and Spitzer space telescopes have combined their efforts to survey the region in unprecedented detail in infrared light. Milky Way's center because visible light is more greatly obscured by dust. The above image encompasses over 2,000 images from the Hubble Space Telescope's NICMOS taken in 2008. The image spans 300 by 115 light years with such high resolution that structures only 20 times the size of our own Solar System are discernable. Clouds of glowing gas and dark dust as well as...
  • Astronomy Picture of the Day -- Comet Lovejoy's Tail

    01/17/2015 8:42:18 AM PST · by SunkenCiv · 7 replies
    NASA ^ | January 17, 2015 | (see photo credit)
    Explanation: Sweeping north in planet Earth's sky, Comet Lovejoy's greenish coma and blue tinted ion tail stretched across this field of stars in the constellation Taurus on January 13. The inset at the upper left shows the 1/2 degree angular size of the full moon for scale. So Lovejoy's coma appears only a little smaller (but much fainter) than a full moon on the sky, and its tail is visible for over 4 degrees across the frame. That corresponds to over 5 million kilometers at the comet's estimated distance of 75 million kilometers from Earth. Blown by the solar wind,...
  • Astronomy Picture of the Day -- Huygens Lands on Titan [flashback]

    01/16/2015 5:24:30 AM PST · by SunkenCiv · 6 replies
    NASA ^ | January 16, 2015 | (see photo credit)
    Explanation: Delivered by Saturn-bound Cassini, ESA's Huygens probe touched down on the ringed planet's largest moon Titan, ten years ago on January 14, 2005. These panels show fisheye images made during its slow descent by parachute through Titan's dense atmosphere. Taken by the probe's descent imager/spectral radiometer instrument they range in altitude from 6 kilometers (upper left) to 0.2 kilometers (lower right) above the moon's surprisingly Earth-like surface of dark channels, floodplains, and bright ridges. But at temperatures near -290 degrees C, the liquids flowing across Titan's surface are methane and ethane, hydrocarbons rather than water. After making the most...
  • Astronomy Picture of the Day -- Venus and Mercury at Sunset

    01/15/2015 4:23:51 AM PST · by SunkenCiv · 7 replies
    NASA ^ | January 15, 2015 | (see photo credit)
    Explanation: Inner planets Venus and Mercury can never wander far from the Sun in Earth's sky. This week you've probably seen them both gathered near the western horizon just after sunset, a close conjunction of bright celestial beacons in the fading twilight. The pair are framed in this early evening skyview captured on January 13 from the ruins of Szarvasko Castle in northwestern Hungary. Above the silhouette of the landscape's prominent volcanic hill Venus is much the brighter, separated from Mercury by little more than the width of two Full Moons. On Friday, planet Earth's early morning risers will also...
  • Astronomy Picture of the Day -- The Hunter, the Bull, and Lovejoy

    01/14/2015 8:19:27 AM PST · by SunkenCiv · 2 replies
    NASA ^ | January 14, 2015 | (see photo credit)
    Explanation: Heading north, Comet Lovejoy (C/2014 Q2) is putting on its best show for comet watchers now, with moonlight absent from mid-January's early evening skies. An easy binocular target and just visible to the unaided eye from dark sites, the comet sweeps across the constellation Taurus the Bull in this deep night skyscape. The starry scene was captured just two days ago on January 12, from Jackson Hole, Wyoming, planet Earth. In fact, the head of Taurus formed by the V-shaped Hyades star cluster points toward Lovejoy at the right. The comet's greenish coma and tail streaming in the anti-sunward...
  • Astronomy Picture of the Day -- The Soap Bubble Nebula

    01/13/2015 12:18:40 PM PST · by SunkenCiv · 9 replies
    NASA ^ | January 13, 2015 | (see photo credit)
    Explanation: Adrift in the rich star fields of the constellation Cygnus, this lovely, symmetric nebula was only recognized a few years ago and does not yet appear in some astronomical catalogs. In fact, amateur astronomer Dave Jurasevich identified it as a nebula on 2008 July 6 in his images of the complex Cygnus region that included the Crescent Nebula (NGC 6888). He subsequently notified the International Astronomical Union. Only eleven days later the same object was independently identified by Mel Helm at Sierra Remote Observatories, imaged by Keith Quattrocchi and Helm, and also submitted to the IAU as a potentially...
  • Astronomy Picture of the Day -- SuperPlanetCrash [game]

    01/12/2015 1:00:16 AM PST · by SunkenCiv · 10 replies
    NASA ^ | January 12, 2015 | (see photo credit)
    SuperPlanetCrash Click on the type of body to add next: 1xEarth5xSuper-Earth15xIce giant300xGiant planet5,000xBrown dwarf30,000xDwarf star HelpEnd Game CloseNew game To beat Super Planet Crash, create a planetary system that can survive for 500 years. You can gain more points by adding more bodies (up to 10 bodies). Add bodies by clicking anywhere.The more massive the body, the more points! From 1 point for an Earth-mass planet, to 30,000 for a stellar companion. But remember, each planet attracts each other gravitationally and you don't want your system to go KABOOM!You will lose the game if two bodies crash with each...
  • Astronomy Picture of the Day -- Cataclysmic Dawn [art]

    01/11/2015 11:49:40 AM PST · by SunkenCiv · 20 replies
    NASA ^ | January 11, 2015 | (see photo credit)
    Explanation: Will this dawn bring another nova? Such dilemmas might be pondered one day by future humans living on a planet orbiting a cataclysmic variable binary star system. Cataclysmic variables involve gas falling from a large star onto an accretion disk surrounding a massive but compact white dwarf star. Explosive cataclysmic events such as a dwarf nova can occur when a clump of gas in the interior of the accretion disk heats up past a certain temperature. At that point, the clump will fall more quickly onto the white dwarf and land with a bright flash. Such dwarf novas will...
  • Astronomy Picture of the Day -- The Windmill's Moon

    01/10/2015 6:22:29 AM PST · by SunkenCiv · 16 replies
    NASA ^ | January 10, 2015 | (see photo credit)
    Explanation: Seen from the Canary Island of Fuerteventura, this bright Full Moon rose at sunset. Reaching its full phase on the night of January 4/5, it was the first Full Moon of the new year and the first to follow December's solstice. Of course, in North America the first Full Moon of January has been known as the Wolf's Moon. But this Full Moon, posed in the twilight above an island of strong winds and traditional windmills, suggests another name. The telephoto image, taken at a distance from the foreground windmill, creates the dramatic comparison in apparent size for windmill...
  • Astronomy Picture of the Day -- In the Arms of NGC 1097

    01/10/2015 6:20:58 AM PST · by SunkenCiv · 3 replies
    NASA ^ | January 09, 2015 | (see photo credit)
    Explanation: Spiral galaxy NGC 1097 shines in southern skies, about 45 million light-years away in the chemical constellation Fornax. Its blue spiral arms are mottled with pinkish star forming regions in this colorful galaxy portrait. They seem to have wrapped around a small companion galaxy below and left of center, about 40,000 light-years from the spiral's luminous core. That's not NGC 1097's only peculiar feature, though. The very deep exposure hints of faint, mysterious jets, most easily seen to extend well beyond the bluish arms toward the left. In fact, four faint jets are ultimately recognized in optical images of...
  • Astronomy Picture of the Day -- Stars and Dust in Corona Australis

    01/08/2015 5:16:18 AM PST · by SunkenCiv · 4 replies
    NASA ^ | January 08, 2015 | (see photo credit)
    Explanation: Cosmic dust clouds and young, energetic stars inhabit this telescopic vista, less than 500 light-years away toward the northern boundary of Corona Australis, the Southern Crown. The dust clouds effectively block light from more distant background stars in the Milky Way. But the striking complex of reflection nebulae cataloged as NGC 6726, 6727, and IC 4812 produce a characteristic blue color as light from the region's young hot stars is reflected by the cosmic dust. The dust also obscures from view stars still in the process of formation. At the left, smaller yellowish nebula NGC 6729 bends around young...
  • Astronomy Picture of the Day -- Hubble 25th Anniversary: Pillars of Creation

    01/07/2015 8:50:27 AM PST · by SunkenCiv · 8 replies
    NASA ^ | January 07, 2015 | (see photo credit)
    Explanation: To celebrate 25 years (1990-2015) of exploring the Universe from low Earth orbit, the Hubble Space Telescope's cameras were used to revisit its most iconic image. The result is this sharper, wider view of the region dubbed the Pillars of Creation, first imaged by Hubble in 1995. Stars are forming deep inside the towering structures. The light-years long columns of cold gas and dust are some 6,500 light-years distant in M16, the Eagle Nebula, toward the constellation Serpens. Sculpted and eroded by the energetic ultraviolet light and powerful winds from M16's cluster of young, massive stars, the cosmic pillars...
  • Astronomy Picture of the Day -- 100 Million Stars in the Andromeda Galaxy

    01/06/2015 4:47:39 AM PST · by SunkenCiv · 22 replies
    NASA ^ | January 06, 2015 | (see photo credit)
    Explanation: What stars compose the Andromeda galaxy? To better understand, a group of researchers studied the nearby spiral by composing the largest image ever taken with the Hubble Space Telescope. The result, called the Panchromatic Hubble Andromeda Treasury (PHAT), involved thousands of observations, hundreds of fields, spanned about a third of the galaxy, and resolved over 100 million stars. In the featured composite image, the central part of the galaxy is seen on the far left, while a blue spiral arm is prominent on the right. The brightest stars, scattered over the frame, are actually Milky Way foreground stars. The...
  • Astronomy Picture of the Day -- A Fox Fur, a Unicorn, and a Christmas Tree

    01/05/2015 7:57:10 AM PST · by SunkenCiv · 4 replies
    NASA ^ | January 05, 2015 | (see photo credit)
    Explanation: What do the following things have in common: a cone, the fur of a fox, and a Christmas tree? Answer: they all occur in the constellation of the unicorn (Monoceros). Pictured as a star forming region and 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 image spans about the diameter of...
  • Astronomy Picture of the Day -- Crescent Rhea Occults Crescent Saturn

    01/04/2015 7:50:02 AM PST · by SunkenCiv · 13 replies
    NASA ^ | January 04, 2015 | (see photo credit)
    Explanation: Soft hues, partially lit orbs, a thin trace of the ring, and slight shadows highlight this understated view of the majestic surroundings of the giant planet Saturn. Looking nearly back toward the Sun, the robot Cassini spacecraft now orbiting Saturn captured crescent phases of Saturn and its moon Rhea in color a few years ago. As striking as the above image is, it is but a single frame from a 60-frame silent movie where Rhea can be seen gliding in front of its parent world. Since Cassini was nearly in the plane of Saturn's rings, the normally impressive rings...
  • Astronomy Picture of the Day -- Apollo 17: A Stereo View from Lunar Orbit

    01/03/2015 6:30:15 AM PST · by SunkenCiv · 5 replies
    NASA ^ | January 03, 2015 | (see photo credit)
    Explanation: Get out your red/blue glasses and check out this awesome stereo view of another world. The scene was recorded by Apollo 17 mission commander Eugene Cernan on December 11, 1972, one orbit before descending to land on the Moon. The stereo anaglyph was assembled from two photographs (AS17-147-22465, AS17-147-22466) captured from his vantage point on board the Lunar Module Challenger as he and Dr. Harrison Schmitt flew over Apollo 17's landing site in the Taurus-Littrow Valley. The broad, sunlit face of the mountain dubbed South Massif rises near the center of the frame, above the dark floor of Taurus-Littrow...
  • Astronomy Picture of the Day -- At the Heart of Orion

    01/02/2015 2:10:37 AM PST · by SunkenCiv · 10 replies
    NASA ^ | January 02, 2015 | (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. Tightly 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 dynamical study indicates that runaway stellar collisions at an earlier age...
  • Astronomy Picture of the Day -- Vela Supernova Remnant

    01/01/2015 2:53:17 AM PST · by SunkenCiv · 6 replies
    NASA ^ | January 01, 2015 | (see photo credit)
    Explanation: The plane of our Milky Way Galaxy runs through this complex and beautiful skyscape. At the northwestern edge of the constellation Vela (the Sails) the telescopic frame is over 10 degrees wide, centered on the brightest glowing filaments of the Vela Supernova Remnant, an expanding debris cloud from the death explosion of a massive star. Light from the supernova explosion that created the Vela remnant reached Earth about 11,000 years ago. In addition to the shocked filaments of glowing gas, the cosmic catastrophe also left behind an incredibly dense, rotating stellar core, the Vela Pulsar. Some 800 light-years distant,...
  • Astronomy Picture of the Day -- Comet Lovejoy before a Globular Star Cluster

    12/31/2014 11:47:49 AM PST · by SunkenCiv · 19 replies
    NASA ^ | December 31, 2014 | (see photo credit)
    Explanation: Comet Lovejoy has become visible to the unaided eye. To see the comet, just go outside an hour or so after sunset and look for a fuzzy patch to the right of Orion's belt. Binoculars and a star chart may help. Pictured here, Comet C/2014 Q2 (Lovejoy) was captured three days ago passing nearly in front of M79, the globular star cluster visible as the bright spot slightly above and to the left of the comet's green-hued coma. The nucleus of Comet Lovejoy is a giant dirty iceberg that is shedding gas into a long and intricate ion tail,...
  • Astronomy Picture of the Day -- Observatory, Mountains, Universe

    12/30/2014 5:32:20 AM PST · by SunkenCiv · 3 replies
    NASA ^ | December 30, 2014 | (see photo credit)
    Explanation: The awesomeness in this image comes in layers. The closest layer, in the foreground, contains the Peak Terskol Observatory located in the northern Caucasus Mountains of Russia. The white dome over the 2-meter telescope is clearly visible. The observatory is located on a shoulder of Mt. Elbrus, the highest mountain in Europe, with other peaks visible in a nearby background layer. Clouds are visible both in front of and behind the mountain peaks. The featured three-image composite panorama was taken in 2014 August. Far in the distance is the most distant layer: the stars and nebulas of the night...
  • Astronomy Picture of the Day -- The Sun in X-rays from NuSTAR

    12/29/2014 4:04:56 AM PST · by SunkenCiv · 13 replies
    NASA ^ | December 29, 2014 | (see photo credit)
    Explanation: Why are the regions above sunspots so hot? Sunspots themselves are a bit cooler than the surrounding solar surface because the magnetic fields that create them reduce convective heating. It is therefore unusual that regions overhead -- even much higher up in the Sun's corona -- can be hundreds of times hotter. To help find the cause, NASA directed the Earth-orbiting Nuclear Spectroscopic Telescope Array (NuSTAR) satellite to point its very sensitive X-ray telescope at the Sun. Featured above is the Sun in ultraviolet light, shown in a red hue as taken by the orbiting Solar Dynamics Observatory (SDO)....
  • Astronomy Picture of the Day -- Unusual Light Pillars over Latvia

    12/28/2014 6:17:59 AM PST · by SunkenCiv · 13 replies
    NASA ^ | December 28, 2014 | (see photo credit)
    Explanation: What's happening over that town? Close inspection shows these strange columns of light occur over bright lights, and so likely are light pillars that involve falling ice crystals reflecting back these lights. The above image and several similar images were taken with a standard digital camera in Sigulda, Latvia in late 2009. The reason why these pillars fan out at the top, however, remains a topic for speculation. The air was noted to be quite cold and indeed filled with small ice crystals, just the type known to create several awe-inspiring but well known sky phenomena such as light...
  • Astronomy Picture of the Day -- The Winter Shower

    12/27/2014 5:56:42 AM PST · by SunkenCiv · 4 replies
    NASA ^ | December 27, 2014 | (see photo credit)
    Explanation: Known in the north as a winter meteor shower, the 2014 Geminids rain down on this rugged, frozen landscape. The scene was recorded from the summit of Mt. Changbai along China's northeastern border with North Korea as a composite of digital frames capturing bright meteors near the shower's peak. Orion is near picture center above the volcanic cater lake. The shower's radiant in the constellation Gemini is to the upper left, at the apparent orgin of all the meteor streaks. Paying the price for such a dreamlike view of the celestial spectacle, photographer Jia Hao reports severe wind gusts...
  • Astronomy Picture of the Day -- Cetus Duo M77 and NGC 1055

    12/26/2014 1:39:39 AM PST · by SunkenCiv · 2 replies
    NASA ^ | December 26, 2014 | (see photo credit)
    Explanation: At the top right, large spiral galaxy NGC 1055 joins spiral Messier 77 in this sharp cosmic view toward the aquatic constellation Cetus. The narrowed, dusty appearance of edge-on spiral NGC 1055 contrasts nicely with the face-on view of M77's bright nucleus and spiral arms. Both over 100,000 light-years across, the pair are dominant members of a small galaxy group about 60 million light-years away. At that estimated distance, M77 is one of the most remote objects in Charles Messier's catalog and is separated from fellow island universe NGC 1055 by at least 500,000 light-years. The field of view...
  • Astronomy Picture of the Day -- This Comet Lovejoy

    12/25/2014 4:29:32 PM PST · by SunkenCiv · 20 replies
    NASA ^ | December 25, 2014 | (see photo credit)
    Explanation: Comet Lovejoy, C/2014 Q2, is framed like a cosmic Christmas tree with starry decorations in this colorful telescopic portrait, snapped on December 16th. Its lovely coma is tinted green by diatomic C2 gas fluorescing in sunlight. Discovered in August of this year, this Comet Lovejoy is currently sweeping north through the constellation Columba, heading for Lepus south of Orion and bright enough to offer good binocular views. Not its first time through the inner Solar System, this Comet Lovejoy will pass closest to planet Earth on January 7, while its perihelion (closest point to the Sun) will be on...
  • Astronomy Picture of the Day -- The Cliffs of Comet Churyumov–Gerasimenko

    12/24/2014 5:24:51 AM PST · by SunkenCiv · 14 replies
    NASA ^ | December 23, 2014 | (see photo credit)
    Explanation: These high cliffs occur on the surface of a comet. They were discovered to be part of the dark nucleus of Comet Churyumov–Gerasimenko (CG) by Rosetta, a robotic spacecraft launched by ESA which began orbiting the comet in early August. The ragged cliffs, as featured here, were imaged by Rosetta about two weeks ago. Although towering about one kilometer high, the low surface gravity of Comet CG would likely make a jump from the cliffs, by a human, survivable. At the foot of the cliffs is relatively smooth terrain dotted with boulders as large as 20 meters across. Data...
  • Astronomy Picture of the Day -- The Mysterious Methane of Mars

    12/24/2014 5:19:45 AM PST · by SunkenCiv · 4 replies
    NASA ^ | December 22, 2014 | (see photo credit)
    Explanation: What's creating methane on Mars? Recent measurements from the robotic Curiosity rover currently rolling across Mars indicate a surprising 10-fold increase in atmospheric methane between measurements only months apart. Life is a major producer of methane on Earth, and so speculation is rampant that some sort of life -- possibly microbial life -- is creating methane beneath the surface of Mars. Other possibilities do exist, though, with a leading model being the sudden release of methane produced by the mixing of specific soil chemicals with underground water. Proposed origins of Martian methane are depicted in the featured illustration. The...
  • Astronomy Picture of the Day -- Tyrrhenian Sea and Solstice Sky

    12/21/2014 1:43:42 PM PST · by SunkenCiv · 8 replies
    NASA ^ | December 21, 2014 | (see photo credit)
    Explanation: Today the solstice occurs at 23:03 Universal Time, the Sun reaching its southernmost declination in planet Earth's sky. Of course, the December solstice marks the beginning of winter in the northern hemisphere and summer in the south. When viewed from northern latitudes, and as shown in the above horizontally compressed image, the Sun will make its lowest arc through the sky along the southern horizon. So in the north, the solstice day has the shortest length of time between sunrise and sunset and fewest hours of daylight. This striking composite image follows the Sun's path through the December solstice...
  • Astronomy Picture of the Day -- Apollo 11 Landing Site Panorama

    12/20/2014 6:54:38 AM PST · by SunkenCiv · 23 replies
    NASA ^ | December 20, 2014 | (see photo credit)
    Explanation: Have you seen a panorama from another world lately? Assembled from high-resolution scans of the original film frames, this one sweeps across the magnificent desolation of the Apollo 11 landing site on the Moon's Sea of Tranquility. Taken by Neil Armstrong looking out his window of the Eagle Lunar Module, the frame at the far left (AS11-37-5449) is the first picture taken by a person on another world. Toward the south, thruster nozzles can be seen in the foreground on the left, while at the right, the shadow of the Eagle is visible toward the west. For scale, the...
  • Astronomy Picture of the Day -- Reflections on the 1970s

    12/20/2014 6:50:51 AM PST · by SunkenCiv · 24 replies
    NASA ^ | December 19, 2014 | (see photo credit)
    Explanation: The 1970s are sometimes ignored by astronomers, like this beautiful grouping of reflection nebulae in Orion - NGC 1977, NGC 1975, and NGC 1973 - usually overlooked in favor of the substantial glow from the nearby stellar nursery better known as the Orion Nebula. Found along Orion's sword just north of the bright Orion Nebula complex, these reflection nebulae are also associated with Orion's giant molecular cloud about 1,500 light-years away, but are dominated by the characteristic blue color of interstellar dust reflecting light from hot young stars. In this sharp color image a portion of the Orion Nebula...
  • Astronomy Picture of the Day -- NGC 7331 and Beyond

    12/18/2014 9:13:33 AM PST · by SunkenCiv · 17 replies
    NASA ^ | December 18, 2014 | (see photo credit)
    Explanation: Big, beautiful spiral galaxy NGC 7331 is often touted as an analog to our own Milky Way. About 50 million light-years distant in the northern constellation Pegasus, NGC 7331 was recognized early on as a spiral nebula and is actually one of the brighter galaxies not included in Charles Messier's famous 18th century catalog. Since the galaxy's disk is inclined to our line-of-sight, long telescopic exposures often result in an image that evokes a strong sense of depth. The effect is further enhanced in this sharp image from a small telescope by galaxies that lie beyond the gorgeous island...
  • Astronomy Picture of the Day -- Geminid Fireball over Mount Balang

    12/18/2014 9:08:45 AM PST · by SunkenCiv · 5 replies
    NASA ^ | December 17, 2014 | (see photo credit)
    Explanation: This was a sky to remember. While viewing the Geminids meteor shower a few days ago, a bright fireball was captured over Mt. Balang, China with particularly picturesque surroundings. In the foreground, a sea of light clouds slowly floated between dark mountain peaks. In the background, the constellation of Orion shone brightly, with the familiar three stars of Orion's belt visible near the image top right. Sirius, the brightest star in the night sky, is visible near the image center. The bright fireball flashed for only a fraction of second on the lower right. The source of the fireball...
  • Astronomy Picture of the Day -- W5: Pillars of Star Formation

    12/16/2014 2:05:46 PM PST · by SunkenCiv · 7 replies
    NASA ^ | December 16, 2014 | (see photo credit)
    Explanation: How do stars form? Images of the star forming region W5 like those in the infrared by NASA's Wide Field Infrared Survey Explorer (WISE) satellite provide clear clues with indications that massive stars near the center of empty cavities are older than stars near the edges. A likely reason for this is that the older stars in the center are actually triggering the formation of the younger edge stars. The triggered star formation occurs when hot outflowing gas compresses cooler gas into knots dense enough to gravitationally contract into stars. In the featured scientifically-colored infrared image, spectacular pillars, left...
  • Astronomy Picture of the Day -- The Potsdam Gravity Potato

    12/15/2014 3:22:41 AM PST · by SunkenCiv · 50 replies
    NASA ^ | December 15, 2014 | (see photo credit)
    Explanation: Why do some places on Earth have higher gravity than others? Sometimes the reason is unknown. To help better understand the Earth's surface, sensitive measurments by the orbiting satellites GRACE and CHAMP were used to create a map of Earth's gravitational field. Since a center for studying this data is in Potsdam, Germany, and since the result makes the Earth look somewhat like a potato, the resulting geoid has been referred to as the Potsdam Gravity Potato. High areas on this map, colored red, indicate areas where gravity is slightly stronger than usual, while in blue areas gravity is...
  • Astronomy Picture of the Day -- Molecular Cloud Barnard 68

    12/14/2014 8:07:43 AM PST · by SunkenCiv · 16 replies
    NASA ^ | December 14, 2014 | (see photo credit)
    Explanation: Where did all the stars go? What used to be considered a hole in the sky is now known to astronomers as a dark molecular cloud. Here, a high concentration of dust and molecular gas absorb practically all the visible light emitted from background stars. The eerily dark surroundings help make the interiors of molecular clouds some of the coldest and most isolated places in the universe. One of the most notable of these dark absorption nebulae is a cloud toward the constellation Ophiuchus known as Barnard 68, pictured above. That no stars are visible in the center indicates...
  • Astronomy Picture of the Day -- The Infrared Visible Andromeda

    12/13/2014 5:49:17 AM PST · by SunkenCiv · 4 replies
    NASA ^ | December 13, 2014 | (see photo credit)
    Explanation: This remarkable synthetic color composite image was assembled from archives of visible light and infrared astronomy image data. The field of view spans the Andromeda Galaxy (M31), a massive spiral a mere 2.5 million light-years away. In fact, with over twice the diameter of our own Milky Way, Andromeda is the largest nearby galaxy. Andromeda's population of bright young blue stars lie along its sweeping spiral arms, with the telltale reddish glow of star forming regions traced in space- and ground-based visible light data. But infrared data from the Spitzer Space Telescope, also blended directly into the detailed composite's...
  • Astronomy Picture of the Day -- Crystals on Mars

    12/13/2014 5:44:56 AM PST · by SunkenCiv · 11 replies
    NASA ^ | December 12, 2014 | (see photo credit)
    Explanation: This extreme close-up, a mosaic from the Mars Hand Lens Imager (MAHLI) on the Curiosity rover, spans a breathtaking 5 centimeters. It captures what appear to be elongated crystal shapes formed by the precipitation of minerals dissolved in water, a likely result of the evaporation of ancient lake or river from the Martian surface. Brushed by a dust removal tool and illuminated by white LEDs, the target rock named Mojave was found on the Pink Cliffs outcrop of the Pahrump Hills at the base of Mount Sharp. The MAHLI images were acquired on Curiosity's sol 809, known on planet...
  • Astronomy Picture of the Day -- Moondog Night

    12/11/2014 7:16:15 AM PST · by SunkenCiv · 6 replies
    NASA ^ | December 11, 2014 | (see photo credit)
    Explanation: In this night scene from the early hours of November 14, light from a last quarter Moon illuminates clouds above the mountaintop domes of Kitt Peak National Observatory near Tucson, Arizona. Bright Jupiter is just left of the overexposed lunar disk with a streak of camera lens flare immediately to the right, but that's no fireball meteor exploding near the center of the picture. Instead, from the roadside perspective a stunningly bright moondog or paraselene stands directly over Kitt Peaks's WIYN telescope. Analogous to a sundog or parhelion, a paraselene is produced by moonlight refracted through thin, hexagonal, plate-shaped...
  • Astronomy Picture of the Day -- The Reddening of M71

    12/10/2014 10:07:57 AM PST · by SunkenCiv · 2 replies
    NASA ^ | December 10, 2014 | (see photo credit)
    Explanation: Now known to be a globular star cluster at the tender age of 10 billion years, M71 is a mere 13,000 light-years away within the narrow boundaries of the faint constellation Sagitta. Close to the plane of the Milky Way galaxy in planet Earth's sky, its 10,000 or so member stars are gathered into a region about 27 light-years across near the center of this color composite view. In fact, the line-of-sight to M71 passes along the galactic plane through much intervening diffuse interstellar dust. The dust dims starlight and scatters blue light more efficiently, masking the brightness of...