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Keyword: astronomy

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  • Astronomy Picture of the Day -- NGC 6960: The Witch's Broom Nebula

    05/28/2013 9:16:27 PM PDT · by SunkenCiv · 3 replies
    NASA ^ | May 29, 2013 | (see photo credit)
    Explanation: Ten thousand years ago, before the dawn of recorded human history, a new light would have suddenly have appeared in the night sky and faded after a few weeks. Today we know this light was from a supernova, or exploding star, and record the expanding debris cloud as the Veil Nebula, a supernova remnant. This sharp telescopic view is centered on a western segment of the Veil Nebula cataloged as NGC 6960 but less formally known as the Witch's Broom Nebula. Blasted out in the cataclysmic explosion, the interstellar shock wave plows through space sweeping up and exciting interstellar...
  • Astronomy Picture of the Day -- The Large Cloud of Magellan

    05/28/2013 10:51:23 AM PDT · by SunkenCiv · 4 replies
    NASA ^ | May 28, 2013 | (see photo credit)
    Explanation: The 16th century Portuguese navigator Ferdinand Magellan and his crew had plenty of time to study the southern sky during the first circumnavigation of planet Earth. As a result, two fuzzy cloud-like objects easily visible to southern hemisphere skygazers are known as the Clouds of Magellan, now understood to be satellite galaxies of our much larger, spiral Milky Way galaxy. About 160,000 light-years distant in the constellation Dorado, the Large Magellanic Cloud (LMC) is seen here in a remarkably deep, colorful, and annotated composite image. Spanning about 15,000 light-years or so, it is the most massive of the Milky...
  • Astronomy Picture of the Day -- Bird Sun Dog

    05/26/2013 9:34:42 PM PDT · by SunkenCiv · 5 replies
    NASA ^ | May 27, 2013 | (see photo credit)
    Explanation: Have you ever seen a little rainbow off to the side of the Sun? Rare but rewarding to see, such spectacles are known as sundogs, mock suns or parhelia. Sundogs are just sunlight refracting through hexagonal falling ice crystals in the Earth's atmosphere. When thin ice crystals flitter down nearly horizontally, they best refract sunlight sideways and create sundogs. Alternatively, randomly oriented ice crystals may create a complete circular sun halo. Sundogs occur 22 degrees to each side of a setting or rising Sun, although sometimes nearby clouds can block one or both. The above image was taken through...
  • Astronomy Picture of the Day -- PanSTARRS Anti-Tail Grows

    05/25/2013 9:18:54 PM PDT · by SunkenCiv · 11 replies
    NASA ^ | May 26, 2013 | (see photo credit)
    Explanation: As planet Earth approached the plane of the Comet PanSTARRS (C/2011 L4) orbit on May 23rd, comet watchers were treated to this view of its magnificent anti-tail. The long, narrow anti-tail stretches to the right across this frame for nearly 4 degrees or about 8 times the angular size of the full Moon. The tail trails along the comet's orbit as it leaves the inner solar system behind. An almost edge-on perspective from near the outbound comet's orbital plane enhances the view of the anti-tail and makes it seem to point in the sunward direction, only apparently contrary to...
  • Astronomy Picture of the Day -- Lunar Corona over Cochem Castle

    05/24/2013 9:08:47 PM PDT · by SunkenCiv · 4 replies
    NASA ^ | May 25, 2013 | (see photo credit)
    Explanation: This bat-like apparition does not shine on clouds passing over Gotham city. Instead, the cloud bank in silhouette against a colorful lunar corona was spotted on the evening of May 18 over Cochem, Germany from the banks of the river Mossele. The lunar corona is formed as bright moonlight is diffracted by water droplets in thin clouds drifting in front of the lunar disk. Below it lies the region's historic Cochem Castle dating from the 11th century, and not Wayne Manor. Still, regardless of your location on planet Earth it is well worth scanning the evening skies this weekend,...
  • Dark, massive asteroid to fly by Earth on May 31

    05/24/2013 10:44:22 AM PDT · by Red Badger · 31 replies
    Phys.Org ^ | 05-24-2013 | by Deborah Netburn
    It's 1.7 miles long. Its surface is covered in a sticky black substance similar to the gunk at the bottom of a barbecue. If it impacted Earth it would probably result in global extinction. Good thing it is just making a flyby. Asteroid 1998 QE2 will make its closest pass to Earth on May 31 at 1:59 p.m. PDT. Scientists are not sure where this unusually large space rock, which was discovered 15 years ago, originated. But the mysterious sooty substance on its surface could indicate it may be a result of a comet that flew too close to the...
  • Astronomy Picture of the Day -- Caterpillar Moon

    05/24/2013 4:00:24 AM PDT · by SunkenCiv · 5 replies
    NASA ^ | May 24, 2013 | (see photo credit)
    Explanation: A close series of consecutive exposures are combined in this intriguing composite of the Full Moon slowly crawling, across the sky. Beginning on the upper right at 19:42 UT and ending at 22:14 UT on April 25, the sequence follows the Moon from Germany as it passes through Earth's shadow in a partial lunar eclipse. Near the top, the Moon just grazes the southern edge of Earth's dark central shadow, or umbra. But the decreased brightness in the darker part of the outer shadow region, the penumbra, is also apparent on the lunar disk. In fact, the relative size...
  • Astronomy Picture of the Day -- Messier 109

    05/23/2013 3:51:36 AM PDT · by SunkenCiv · 10 replies
    NASA ^ | May 23, 2013 | (see photo credit)
    Explanation: Beautiful barred spiral galaxy M109, 109th entry in Charles Messier's famous catalog of bright Nebulae and Star Clusters, is found just below the Big Dipper's bowl in the northern constellation Ursa Major. In telescopic views, its striking central bar gives the galaxy the appearance of the Greek letter "theta", θ, a common mathematical symbol representing an angle. Of course M109 spans a very small angle in planet Earth's sky, about 7 arcminutes or 0.12 degrees. But that small angle corresponds to an enormous 120,000 light-year diameter at the galaxy's estimated 60 million light-year distance. The brightest member of the...
  • Astronomy Picture of the Day -- Red Sprite Lightning with Aurora

    05/22/2013 3:37:18 AM PDT · by SunkenCiv · 5 replies
    NASA ^ | May 22, 2013 | (see photo credit)
    Explanation: What's that in the sky? It is a rarely seen form of lightning confirmed only about 25 years ago: a red sprite. Recent research has shown that following a powerful positive cloud-to-ground lightning strike, red sprites may start as 100-meter balls of ionized air that shoot down from about 80-km high at 10 percent the speed of light and are quickly followed by a group of upward streaking ionized balls. The above image, taken a few days ago above central South Dakota, USA, captured a bright red sprite, and is a candidate for the first color image ever recorded...
  • Astronomy Picture of the Day -- The Red Rectangle Nebula from Hubble

    05/21/2013 3:39:45 AM PDT · by SunkenCiv · 6 replies
    NASA ^ | May 21, 2013 | (see photo credit)
    Explanation: How was the unusual Red Rectangle nebula created? At the nebula's center is an aging binary star system that surely powers the nebula but does not, as yet, explain its colors. The unusual shape of the Red Rectangle is likely due to a thick dust torus which pinches the otherwise spherical outflow into tip-touching cone shapes. Because we view the torus edge-on, the boundary edges of the cone shapes seem to form an X. The distinct rungs suggest the outflow occurs in fits and starts. The unusual colors of the nebula are less well understood, however, and speculation holds...
  • Astronomy Picture of the Day -- Blue Sun Bursting

    05/20/2013 3:40:03 AM PDT · by SunkenCiv · 18 replies
    NASA ^ | May 20, 2013 | (see photo credit)
    Explanation: Our Sun is not a giant blueberry. Our Sun can be made to appear similar to the diminutive fruit, however, by imaging it in a specific color of extreme violet light called CaK that is emitted by the very slight abundance of ionized Calcium in the Sun's atmosphere, and then false color-inverting the image. This solar depiction is actually scientifically illuminating as a level of the Sun's chromosphere appears quite prominent, showing a crackly textured surface, cool sunspots appearing distinctly bright, and surrounding hot active regions appearing distinctly dark. The Sun is currently near the maximum activity level in...
  • Astronomy Picture of the Day -- Earth's Richat Structure

    05/19/2013 6:05:54 AM PDT · by SunkenCiv · 26 replies
    NASA ^ | May 19, 2013 | (see photo credit)
    Explanation: What on Earth is that? The Richat Structure in the Sahara Desert of Mauritania is easily visible from space because it is nearly 50 kilometers across. Once thought to be an impact crater, the Richat Structure's flat middle and lack of shock-altered rock indicates otherwise. The possibility that the Richat Structure was formed by a volcanic eruption also seems improbable because of the lack of a dome of igneous or volcanic rock. Rather, the layered sedimentary rock of the Richat structure is now thought by many to have been caused by uplifted rock sculpted by erosion. The above image...
  • Astronomy Picture of the Day -- Comet PanSTARRS Anti-Tail

    05/18/2013 6:07:35 AM PDT · by SunkenCiv · 5 replies
    NASA ^ | May 18, 2013 | (see photo credit)
    Explanation: Once the famous sunset comet, PanSTARRS (C/2011 L4) is now visible all night from much of the northern hemisphere, bound for the outer solar system as it climbs high above the ecliptic plane. Dimmer and fading, the comet's broad dust tail is still growing, though. This widefield telescopic image was taken against the starry background of the constellation Cepheus on May 15. It shows the comet has developed an extensive anti-tail, dust trailing along the comet's orbit (to the left of the coma), stretching more than 3 degrees across the frame. Since the comet is just over 1.6 astronomical...
  • Astronomy Picture of the Day -- The Waterfall and the World at Night

    05/17/2013 3:56:40 AM PDT · by SunkenCiv · 8 replies
    NASA ^ | May 17, 2013 | (see photo credit)
    Explanation: Above this boreal landscape, the arc of the Milky Way and shimmering aurorae flow through the night. Like an echo, below them lies Iceland's spectacular Godafoss, the Waterfall of the Gods. Shining just below the Milky Way, bright Jupiter is included in the panoramic nightscape recorded on March 9. Faint and diffuse, the Andromeda Galaxy (M31) appears immersed in the auroral glow. The digital stitch of four frames is a first place winner in the 2013 International Earth and Sky Photo Contest on Dark Skies Importance organized by The World at Night. An evocative record of the beauty of...
  • Astronomy Picture of the Day -- Four X-class Flares

    05/16/2013 3:40:20 AM PDT · by SunkenCiv · 10 replies
    NASA ^ | May 16, 2013 | (see photo credit)
    Explanation: Swinging around the Sun's eastern limb on Monday, a group of sunspots labeled active region AR1748 has produced the first four X-class solar flares of 2013 in less than 48 hours. In time sequence clockwise from the top left, flashes from the four were captured in extreme ultraviolet images from the Solar Dynamics Observatory. Ranked according to their peak brightness in X-rays, X-class flares are the most powerful class and are frequently accompanied by coronal mass ejections (CMEs), massive clouds of high energy plasma launched into space. But CMEs from the first three flares were not Earth-directed, while one...
  • Astronomy Picture of the Day -- Galaxy Collisions: Simulation vs Observations

    05/15/2013 4:07:29 AM PDT · by SunkenCiv · 17 replies
    NASA ^ | May 14, 2013 | (see photo credit)
    Explanation: What happens when two galaxies collide? Although it may take over a billion years, such titanic clashes are quite common. Since galaxies are mostly empty space, no internal stars are likely to themselves collide. Rather the gravitation of each galaxy will distort or destroy the other galaxy, and the galaxies may eventually merge to form a single larger galaxy. Expansive gas and dust clouds collide and trigger waves of star formation that complete even during the interaction process. Pictured above is a computer simulation of two large spiral galaxies colliding, interspersed with real still images taken by the Hubble...
  • Astronomy Picture of the Day -- Kepler's Supernova Remnant in X-Rays

    05/15/2013 3:48:18 AM PDT · by SunkenCiv · 5 replies
    NASA ^ | May 15, 2013 | (see photo credit)
    Explanation: What caused this mess? Some type of star exploded to create the unusually shaped nebula known as Kepler's supernova remnant, but which type? Light from the stellar explosion that created this energized cosmic cloud was first seen on planet Earth in October 1604, a mere four hundred years ago. The supernova produced a bright new star in early 17th century skies within the constellation Ophiuchus. It was studied by astronomer Johannes Kepler and his contemporaries, without the benefit of a telescope, as they searched for an explanation of the heavenly apparition. Armed with a modern understanding of stellar evolution,...
  • Astronomy Picture of the Day -- Partial Solar Eclipse with Airplane

    05/13/2013 4:02:47 PM PDT · by SunkenCiv · 5 replies
    NASA ^ | May 13, 2013 | (see photo credit)
    Explanation: It was just eight minutes after sunrise, last week, and already there were four things in front of the Sun. The largest and most notable was Earth's Moon, obscuring a big chunk of the Sun's lower limb as it moved across the solar disk, as viewed from Fremantle, Australia. This was expected as the image was taken during a partial solar eclipse -- an eclipse that left sunlight streaming around all sides of the Moon from some locations. Next, a band of clouds divided the Sun horizontally while showing interesting internal structure vertically. The third intervening body might be...
  • Astronomy Picture of the Day -- Clouds, Birds, Moon, Venus

    05/12/2013 2:45:46 PM PDT · by SunkenCiv · 10 replies
    NASA ^ | May 12, 2013 | (see photo credit)
    Explanation: Sometimes the sky above can become quite a show. In early September of 2010, for example, the Moon and Venus converged, creating quite a sight by itself for sky enthusiasts around the globe. From some locations, though, the sky was even more picturesque. In the above image taken in Spain, a crescent Moon and the planet Venus, on the far right, were captured during sunset posing against a deep blue sky. In the foreground, dark storm clouds loom across the image bottom, while a white anvil cloud shape appears above. Black specks dot the frame, caused by a flock...
  • Astronomy Picture of the Day -- Cape York Annular Eclipse

    05/11/2013 7:56:12 AM PDT · by SunkenCiv · 15 replies
    NASA ^ | May 11, 2013 | (see photo credit)
    Explanation: This week the shadow of the New Moon fell on planet Earth, crossing Queensland's Cape York in northern Australia ... for the second time in six months. On the morning of May 10, the Moon's apparent size was too small to completely cover the Sun though, revealing a "ring of fire" along the central path of the annular solar eclipse. Near mid-eclipse from Coen, Australia, a webcast team captured this telescopic snapshot of the annular phase. Taken with a hydrogen-alpha filter, the dramatic image finds the Moon's silhouette just within the solar disk, and the limb of the active...