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Keyword: astronomy

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  • 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...
  • Astronomy Picture of the Day -- IC 4628: The Prawn Nebula

    09/06/2012 9:14:16 PM PDT · by SunkenCiv · 7 replies
    NASA ^ | September 07, 2012 | (see photo credit)
    Explanation: South of Antares, in the tail of the nebula-rich constellation Scorpius, lies emission nebula IC 4628. Nearby hot, massive stars, millions of years young, radiate the nebula with invisible ultraviolet light, stripping electrons from atoms. The electrons eventually recombine with the atoms to produce the visible nebular glow, dominated by the red emission of hydrogen. At an estimated distance of 6,000 light-years, the region shown is about 250 light-years across, spanning an area equivalent to four full moons on the sky. The nebula is also cataloged as Gum 56 for Australian astronomer Colin Stanley Gum, but seafood-loving astronomers might...
  • Astronomy Picture of the Day -- Airglow over Italy

    09/06/2012 8:11:43 PM PDT · by SunkenCiv · 5 replies
    NASA ^ | September 06, 2012 | (see photo credit)
    Explanation: In this serene night skyscape, the Milky Way's graceful arc stretches over prominent peaks in the Italian Alps known as Tre Cime di Lavaredo. A 180 degree wide-angle panorama made in four exposures on August 24, the scene does look to the north and the sky is suffused with an eerie greenish light. Still, the subtle glowing bands are not aurorae, but airglow. Unlike aurorae powered by collisions with energetic charged particles and seen at high latitudes, airglow is due to chemiluminescence, the production of light in a chemical reaction, and found around the globe. The chemical energy is...
  • Astronomy Picture of the Day -- Airglow Over Germany

    09/05/2012 3:00:22 PM PDT · by SunkenCiv · 12 replies
    NASA ^ | September 05, 2012 | (see photo credit)
    Explanation: Does air glow? It does, but it is usually hard to see. When conditions are right, however, a faint glow about 90 kilometers up can be observed, most easily with a wide-angle long-duration camera exposure. The same airglow can also frequently be seen looking down -- in pictures taken from Earth orbit -- as a faint arc hovering above the surface. Pictured above between the beige clouds, above the curving Earth, behind the streaking airplane, and in front of the sparkling stars are some green bands of airglow. The glow is predominantly created by the excitation of atoms by...
  • Astronomy Picture of the Day -- Hurricane Paths on Planet Earth

    09/04/2012 4:04:33 AM PDT · by SunkenCiv · 11 replies
    NASA ^ | September 04, 2012 | (see photo credit)
    Explanation: Should you be worried about hurricanes? To find out, it is useful to know where hurricanes have gone in the past. The above Earth map shows the path of every hurricane reported since 1851, Although striking, a growing incompleteness exists in the data the further one looks back in time. The above map graphically indicates that hurricanes -- sometimes called cyclones or typhoons depending on where they form -- usually occur over water, which makes sense since evaporating warm water gives them energy. The map also shows that hurricanes never cross -- or even occur very near -- the...
  • Astronomy Picture of the Day -- M45: The Pleiades Star Cluster

    09/03/2012 12:23:54 PM PDT · by SunkenCiv · 35 replies
    NASA ^ | September 03, 2012 | (see photo credit)
    Explanation: Perhaps the most famous star cluster on the sky, the Pleiades can be seen without binoculars from even the depths of a light-polluted city. Also known as the Seven Sisters and M45, the Pleiades is one of the brightest and closest open clusters. The Pleiades contains over 3000 stars, is about 400 light years away, and only 13 light years across. Quite evident in the above photograph are the blue reflection nebulae that surround the brighter cluster stars. Low mass, faint, brown dwarfs have also been found in the Pleiades. (Editors' note: The prominent diffraction spikes are caused by...
  • Blue Stars Confirm Recent Creation

    09/01/2012 7:28:34 PM PDT · by lasereye · 102 replies
    Institute for Creation Research ^ | September 2012 | Jason Lisle, Ph.D.
    Orion is one of the most well-known and easily recognized constellations of the winter sky. The three bright blue stars in Orion’s belt seem to draw our attention instantly.1 Such stars are a strong confirmation of the biblical timescale. Most stars generate energy by the process of nuclear fusion of hydrogen into helium in the stellar core. This is a very efficient power source. Theoretically, a star like the sun has enough hydrogen in its core to keep it burning for ten billion years. But that’s not the case with blue stars. Blue stars are always more massive than the...
  • Astronomy Picture of the Day -- RBSP Night Launch

    09/02/2012 6:05:34 AM PDT · by SunkenCiv · 8 replies
    NASA ^ | September 02, 2012 | (see photo credit)
    Explanation: This graceful arc traces a Delta rocket climbing through Thursday's early morning skies over Cape Canaveral Air Force Station in Florida, USA. Snug inside the rocket's Centaur upper stage were NASA's twin Radiation Belt Storm Probes (RBSP), now in separate orbits within planet Earth's Van Allen radiation belts. Reflected in the Turn Basin from a vantage point about 3 miles from Space Launch Complex 41, the scene was captured in a composite of two exposures. One highlights the dramatic play of launch pad lighting, clouds, and sky. A subsequent 3 minute long exposure records the rocket's fiery trail. While...
  • Astronomy Picture of the Day -- On a Blue Moon

    09/01/2012 2:56:41 PM PDT · by SunkenCiv · 26 replies
    NASA ^ | September 01, 2012 | (see photo credit)
    Explanation: Rising at sunset, the gorgeous Full Moon of August 31 became the second Full Moon in a month. According to modern reckoning, that makes it a Blue Moon. In fact, parts of the Full Moon do look a little blue in this sharp lunar portrait. Taken just hours before the exact full phase in delightfully clear skies over Nottingham, UK, it features eye-catching bright rays extending from the prominent young crater Tycho in the Moon's southern hemisphere. The slightly color enhanced image also brings out subtle shades of blue, a real characteristic of terrain with a high content of...
  • Astronomy Picture of the Day -- Halo of the Cat's Eye

    08/30/2012 9:18:44 PM PDT · by SunkenCiv · 5 replies
    NASA ^ | August 31, 2012 | (see photo credit)
    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 tantalizing image, processed to reveal the enormous but extremely faint halo of gaseous material, about 6 light-years across, which surrounds the brighter, familiar planetary nebula. Made with narrow and broadband data the composite picture shows the remarkably strong extended emission from twice ionized oxygen atoms in blue-green hues and ionized hydrogen and nitrogen in red. Planetary nebulae have long been appreciated as a final phase in the life of a...
  • Astronomy Picture of the Day -- Apollo 11 Landing Site Panorama

    08/30/2012 9:18:42 PM PDT · by SunkenCiv · 11 replies
    NASA ^ | August 30, 2012 | (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 -- A Dark Earth with a Red Sprite

    08/29/2012 2:57:57 PM PDT · by SunkenCiv · 3 replies
    NASA ^ | August 29, 2012 | (see photo credit)
    Explanation: There is something very unusual in this picture of the Earth -- can you find it? A fleeting phenomenon once thought to be only a legend has been newly caught if you know just where to look. The above image was taken from the orbiting International Space Station (ISS) in late April and shows familiar ISS solar panels on the far left and part of a robotic arm to the far right. The rarely imaged phenomenon is known as a red sprite and it can be seen, albeit faintly, just over the bright area on the image right. This...
  • Astronomy Picture of the Day -- Colorful Clouds Near Rho Ophiuchi

    08/28/2012 2:52:46 PM PDT · by SunkenCiv · 19 replies
    NASA ^ | August 28, 2012 | (see photo credit)
    Explanation: Why is the sky near Antares and Rho Ophiuchi so colorful? The colors result from a mixture of objects and processes. Fine dust illuminated from the front by starlight produces blue reflection nebulae. Gaseous clouds whose atoms are excited by ultraviolet starlight produce reddish emission nebulae. Backlit dust clouds block starlight and so appear dark. Antares, a red supergiant and one of the brighter stars in the night sky, lights up the yellow-red clouds on the lower center. Rho Ophiuchi lies at the center of the blue nebula near the top. The distant globular cluster M4 is visible just...
  • Astronomy Picture of the Day -- Curiosity on Mars: Mt. Sharp in View

    08/27/2012 3:31:29 PM PDT · by SunkenCiv · 26 replies
    NASA ^ | August 27, 2012 | (see photo credit)
    Explanation: What's that on the horizon? The light peak is Mt. Sharp -- an eventual destination of the Curiosity rover. The above image mosaic was taken from Bradbury Landing, the landing spot of Curiosity, and shows in the foreground the rover's extended robotic arm. Curiosity's is already on the move crossing the intermediate gravel field toward an interesting terrain feature named Glenelg. Curiosity has also already started analyzing its surroundings by zapping a nearby rock with its laser to analyze the chemical composition of the resulting gas plume. If life ever existed on Mars it might well have been here...
  • Astronomy Picture of the Day -- The Cat's Eye Nebula

    08/25/2012 11:40:38 PM PDT · by SunkenCiv · 8 replies
    NASA ^ | August 26, 2012 | (see photo credit)
    Explanation: Three thousand light-years away, a dying star throws off shells of glowing gas. This image from the Hubble Space Telescope reveals the Cat's Eye Nebula to be one of the most complex planetary nebulae known. In fact, the features seen in the Cat's Eye are so complex that astronomers suspect the bright central object may actually be a binary star system. The term planetary nebula, used to describe this general class of objects, is misleading. Although these objects may appear round and planet-like in small telescopes, high resolution images reveal them to be stars surrounded by cocoons of gas...
  • Astronomy Picture of the Day -- Perseid over Albrechtsberg Castle

    08/24/2012 9:12:16 PM PDT · by SunkenCiv · 8 replies
    NASA ^ | August 25, 2012 | (see photo credit)
    Explanation: Medieval Albrechtsberg castle is nestled in trees near the northern bank of the river Pielach and the town of Melk, Austria. In clearing night skies on August 12 it stood under constellations of the northern summer, including Aquarius, Aquila, and faint, compact Delphinus (above and right of center) in this west-looking skyview. The scene also captures a bright meteor above the castle walls. Part of the annual perseid meteor shower, its trail points back toward the heroic constellation Perseus high above the horizon in the early morning hours. Entering the atmosphere at about 60 kilometers per second, perseid meteors...
  • Astronomy Picture of the Day -- Moon Meets Morning Star

    08/24/2012 3:43:24 PM PDT · by SunkenCiv · 9 replies
    NASA ^ | August 24, 2012 | (see photo credit)
    Explanation: Rising in the dark hours before dawn, wandering Venus now shines as the brilliant morning star. Its close conjunction with the Moon on August 13 was appreciated around planet Earth. But skygazers in eastern Asia were also treated to a lunar occultation, the waning crescent Moon passing directly in front of the bright planet in still dark skies. This composite image constructed from frames made at 10 minute intervals follows the celestial performance (vimeo video) from above the city lights and clouds over Taebaek, Korea. The occultation begins near the horizon and progresses as the pair rises. Venus first...