Astronomy Picture of the Day

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Astronomy Picture of the Day

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.
2008 August 5

A Total Solar Eclipse Over China
Credit & Copyright: Bill Buckingham Explanation: What's that black dot over the Sun? The Moon. This past weekend, the Sun went dark during the day as the Moon completely covered it. The total solar eclipse was visible over a thin swath of Earth extending from northern Canada to China. As shown above, many sky enthusiasts gathered to witness the total or partial solar eclipse, which lasted only a few minutes. The above image was taken during totality near Barkol in Xinjiang, China, with the Barkol Shan mountain range visible on the horizon. Although the brightest parts of the Sun are covered, the normally invisible corona of hot gas surrounding the Sun became prominent. Just to the upper left of the Moon darkened Sun are planets Mercury and Venus. The increased darkening of the sky toward the right indicates the darkened atmosphere created by the passing shadow cone of the total solar eclipse. The next total solar eclipse will occur next July and be visible in parts of India and China.


Tomorrow's picture: swirling hole

 

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Astronomy Picture of the Day

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.
2008 August 6

 

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Astronomy Picture of the Day

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.
2008 August 7

At the Sun's Edge
Credit & Copyright: Catalin Beldea (Descopera Magazine) Explanation: A train trip on the Trans-Siberian railway to Novosibirsk resulted in this stunning view along the edge of the Sun recorded during the August 1st total solar eclipse. The picture is a composite of two images taken at special moments in the eclipse sequence, corresponding to the very beginning and the very end of the total eclipse phase. Those times are known to eclipse chasers as 2nd and 3rd contact. Bright beads around the Moon's dark silhouette are rays of sunlight shining through lunar valleys at the edge of the lunar disk. But the composite view also captures solar prominences, looping structures of hot plasma suspended in magnetic fields, extending beyond the Sun's edge.


Tomorrow's picture: the Sun's crown

 

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Astronomy Picture of the Day

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.
2008 August 8

The Crown of the Sun
Credit & Copyright: Hartwig Luethen Explanation: During a total solar eclipse, the Sun's extensive outer atmosphere, or corona, is an inspirational sight. The subtle shades and shimmering features of the corona that engage the eye span a brightness range of over 10,000 to 1, making them notoriously difficult to capture in a single picture. But this composite of 28 digital images ranging in exposure time from 1/1000 to 2 seconds comes close to revealing the crown of the Sun in all its glory. The telescopic views were recorded near Kochenevo, Russia during the August 1 total solar eclipse and also show solar prominences extending just beyond the edge of the eclipsed sun. Remarkably, features on the dark near side of the New Moon can also be made out, illuminated by sunlight reflected from a Full Earth.


Tomorrow's picture: light-weekend

 

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Astronomy Picture of the Day

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.
2008 August 9

Aurora Persei
Credit & Copyright: Jimmy Westlake (Colorado Mountain College) Explanation: Dark skies are favored for viewing meteor showers -- so the best viewing of this year's Perseids will occur in the early morning. While the Perseid meteor shower is scheduled to peak over the next few days, bright light from a gibbous Moon will also flood the early evening and mask the majority of relatively faint meteors. Still, skygazing in the early morning after the Moon sets (after about 2 AM local time) could reveal spectacular earthgrazing meteors. Persisting observing at any time after sunset can reward northern hemisphere watchers looking for occasional Perseid fireballs. Astronomer Jimmy Westlake imaged this bright Perseid meteor despite the combination of moonlight and auroral glow over Colorado skies in August of 2000.


Tomorrow's picture: Stereo Sunday

 

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Astronomy Picture of the Day

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.
2008 August 10

The Eagle Rises
Credit: Apollo 11, NASA - Stereo Image Copyright: John Kaufmann (ALSJ) Explanation: Get out your red/blue glasses and check out this remarkable stereo view from lunar orbit. Created from two photographs (AS11-44-6633, AS11-44-6634) taken by astronaut Michael Collins during the 1969 Apollo 11 mission, the 3D anaglyph features the lunar module ascent stage, dubbed The Eagle, as it rises to meet the command module in lunar orbit. Aboard the ascent stage are Neil Armstrong and Buzz Aldrin, the first to walk on the Moon. The smooth, dark area on the lunar surface is Mare Smythii located just below the equator on the extreme eastern edge of the Moon's near side. Poised beyond the lunar horizon, is our fair planet Earth.
Watch: The Perseid Meteor Shower

Tomorrow's picture: swirling​

 

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Astronomy Picture of the Day

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.
2008 August 11

Black Hole Candidate Cygnus X-1
Credit: ESA, Hubble Explanation: Is that a black hole? Quite possibly. The Cygnus X-1 binary star system contains one of the best candidates for a black hole. The system was discovered because it is one of the brightest X-ray sources on the sky, shining so bright it was detected by the earliest rockets carrying cameras capable of seeing the previously unknown X-ray sky. The star's very name indicates that it is the single brightest X-ray source in the constellation of the Swan Cygnus. Data indicate that a compact object there contains about nine times the mass of the Sun and changes its brightness continually on several time scales, at least down to milliseconds. Such behavior is expected for a black hole, and difficult to explain with other models. Pictured above is an artistic impression of the Cygnus X-1 system. On the left is the bright blue supergiant star designated HDE 226868, which is estimated as having about 30 times the mass of our Sun. Cygnus X-1 is depicted on the right, connected to its supergiant companion by a stream of gas, and surrounded by an impressive accretion disk. The bright star in the Cygnus X-1 system is visible with a small telescope. Strangely, the Cygnus X-1 black hole candidate appears to have formed without a bright supernova explosion.


Tomorrow's picture: mars a pan

 

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Astronomy Picture of the Day

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.
2008 August 12

A Mars Panorama from the Phoenix Lander
Credit: Phoenix Mission Team, NASA, JPL-Caltech, U. Arizona Explanation: If you could stand on Mars, what would you see? The robotic Phoenix spacecraft that just landed on Mars in May recorded the above spectacular panorama. The above image is actually a digital combination of over 100 camera pointings and surveys fully 360 degrees around the busy robotic laboratory. Clicking on the horizontally compressed image above will bring up the extra-wide uncompressed version. Visible in the image foreground are circular solar panels, various Phoenix instruments, rust colored rocks, a trench dug by Phoenix to probe Mars' chemical composition, a vast plateau of dirt and dirt-covered ice, and, far in the distance, the dust colored atmosphere of Mars. Phoenix landed in the far north of Mars and has been using its sophisticated laboratory to search for signs that past life might have been possible. Recent soil analyses have confirmed the presence of ice, but gave conflicting indications of unexpected perchlorate salts. Whether perchlorates exist on Mars is now being aggressively researched, as well as what effects perchlorates might have had on the past development of life.


Tomorrow's picture: Crescent Nebula

 

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Astronomy Picture of the Day

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.
2008 August 13

NGC 6888: The Crescent Nebula
Credit & Copyright: Tony Hallas Explanation: NGC 6888, also known as the Crescent Nebula, is a cosmic bubble about 25 light-years across, blown by winds from its central, bright, massive star. This beautiful telescopic view combines a composite color image with narrow band data that isolates light from hydrogen and oxygen atoms in the wind-blown nebula. The oxygen atoms produce the blue-green hue that seems to enshroud the detailed folds and filaments. NGC 6888's central star is classified as a Wolf-Rayet star (WR 136). The star is shedding its outer envelope in a strong stellar wind, ejecting the equivalent of the Sun's mass every 10,000 years. The nebula's complex structures are likely the result of this strong wind interacting with material ejected in an earlier phase. Burning fuel at a prodigious rate and near the end of its stellar life this star should ultimately go out with a bang in a spectacular supernova explosion. Found in the nebula rich constellation Cygnus, NGC 6888 is about 5,000 light-years away.


Tomorrow's picture: falling stars

 

[ig0r]

Ouh! i first time in this theme!!!
Very interesting photo!!!Super!
Thanks @ Maximus

 

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Astronomy Picture of the Day

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.
2008 August 14

Perseid Trail
Credit & Copyright: Wally Pacholka (Astropics.com / TWAN) Explanation: This bright and colorful meteor flashed through Tuesday's early morning skies, part of the annual Perseid Meteor Shower. The lovely image is one of over 350 frames captured on August 12 from the Joshua Tree National Park, in California, USA . Dust from comet Swift-Tuttle is responsible for the Perseids, creating the northern hemisphere's regular summer sky show. The comet dust is vaporized as it enters the atmosphere at upwards of 60 kilometers per second, producing visible trails that begin at altitudes of around 100 kilometers. Of course, the trails point back to a radiant point in the constellation Perseus, giving the meteor shower its name. Recorded after moonset, the starry background features the bright star Vega on the right. Extending below the western horizon is the faint band of the northern Milky Way.


Tomorrow's picture: skyview

 

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Astronomy Picture of the Day

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.
2008 August 15

Facing NGC 6946
Credit & Copyright: Volker Wendel (Spiegelteam) Explanation: From our vantage point in the Milky Way Galaxy, we see NGC 6946 face-on. The big, beautiful spiral galaxy is located just 10 million light-years away, behind a veil of foreground dust and stars in the high and far-off constellation of Cepheus. From the core outward, the galaxy's colors change from the yellowish light of old stars in the center to young blue star clusters and reddish star forming regions along the loose, fragmented spiral arms. NGC 6946 is also bright in infrared light and rich in gas and dust, exhibiting a high star birth and death rate. In fact, since the early 20th century at least nine supernovae, the death explosions of massive stars, were discovered in NGC 6946. In this deep color composite image, a small barred structure is just visible at the galaxy's core. Nearly 40,000 light-years across, NGC 6946 is also known as the Fireworks Galaxy.
Watch: Saturday's partial lunar eclipse - Times and Visibility | Webcast

Tomorrow's picture: by the lake

 

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Astronomy Picture of the Day

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.
2008 August 16

Perseid over Vancouver
Credit & Copyright: Yuichi Takasaka (www.blue-moon.ca / TWAN) Explanation: Colorful and bright, the city lights of Vancouver, Canada are reflected in the water in this portrait of the world at night. Recorded on August 12 during the Perseid Meteor Shower, the wide-angle view takes in a large swath along the photographer's eastern horizon. The picture is a composite of many consecutive 2 second exposures that, when added together, cover a total time of an hour and 33 minutes. During that time, stars trailed through the night sky above Vancouver, their steady motion along concentric arcs a reflection of planet Earth's rotation. The dotted trails of aircraft also cut across the scene. Of course, two of the frames captured the brief, brilliant flash of a Perseid fireball as it tracked across the top of the field of view. The large gap in the single meteor trail corresponds to the time gap between the consecutive frames.
Watch: Saturday's partial lunar eclipse - Times and Visibility | Webcast

Tomorrow's picture: construction zone

 

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Astronomy Picture of the Day

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.
2008 August 17

Io's Surface: Under Construction
Credit: Galileo Project, JPL, NASA Explanation: Like the downtown area of your favorite city, the roads you drive to work on, and any self-respecting web site ... Io's surface is constantly under construction. This moon of Jupiter holds the distinction of being the Solar System's most volcanically active body -- its bizarre looking surface continuously formed and reformed by lava flows. Generated using 1996 data from NASA's Galileo spacecraft, this high resolution composite image is centered on the side of Io that always faces away from Jupiter. It has been enhanced to emphasize Io's surface brightness and color variations, revealing features as small as 1.5 miles across. The notable absence of impact craters suggests that the entire surface is covered with new volcanic deposits much more rapidly than craters are created. What drives this volcanic powerhouse? A likely energy source is the changing gravitational tides caused by Jupiter and the other Galilean moons as Io orbits the massive gas giant planet. Heating Io's interior, the pumping tides would generate the sulfurous volcanic activity.


Tomorrow's picture: moon beads​

 

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Astronomy Picture of the Day

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.
2008 August 18

Baily's Beads near Solar Eclipse Totality
Credit & Copyright: Leonid Durman Explanation: Just before the Sun blacks out, something strange occurs. As the Moon moves to completely cover the Sun in a total solar eclipse, beads of bright sunlight stream around the edge of the Moon. This effect, known as Baily's beads, is named after Francis Baily who called attention to the phenomenon in 1836. Although, the number and brightness of Baily's beads used to be unpredictable, today the Moon is so well mapped that general features regarding Baily's beads are expected. When a single bead dominates, it is called the diamond ring effect, and is typically seen just before totality. Pictured above, a series of images recorded Baily's beads at times surrounding the recent total solar eclipse visible from Novosibirsk, Russia. The complete series can be seen by scrolling right. At the end of totality, as the Sun again emerges from behind the moon, Baily's beads may again be visible -- but now on the other side of the Moon.


Tomorrow's picture: gas broom​

 

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Astronomy Picture of the Day

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.
2008 August 19

NGC 6960: The Witch's Broom Nebula
Credit & Copyright: Adam Block, Mount Lemmon SkyCenter, Univ. Arizona Explanation: Ten thousand years ago, before the dawn of recorded human history, a new light must suddenly have appeared in the night sky and faded after a few weeks. Today we know this light was an exploding star and record the colorful expanding cloud as the Veil Nebula. Pictured above is the west end of the Veil Nebula known technically as NGC 6960 but less formally as the Witch's Broom Nebula. The expanding debris cloud gains its colors by sweeping up and exciting existing nearby gas. The supernova remnant lies about 1400 light-years away towards the constellation of Cygnus. This Witch's Broom actually spans over three times the angular size of the full Moon. The bright star 52 Cygnus is visible with the unaided eye from a dark location but unrelated to the ancient supernova.


Tomorrow's picture: shadow play

 

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Astronomy Picture of the Day

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.
2008 August 20

Earth's Shadow
Credit & Copyright: Anthony Ayiomamitis (TWAN) Explanation: The dark, inner shadow of planet Earth is called the umbra. Shaped like a cone extending into space, the umbra has a circular cross section that can be most easily seen during a lunar eclipse. For example, last Saturday the Full Moon slid across the northern edge of the umbra. Entertaining moon watchers throughout Earth's eastern hemisphere, the lunar passage created a deep but partial lunar eclipse. This composite image uses successive pictures recorded during the eclipse from Athens, Greece to trace out a large part of the umbra's curved edge. The result nicely illustrates the relative size of the umbra's cross section at the distance of the Moon, as well as the Moon's path through the Earth's shadow.


Tomorrow's picture: August Moons

 

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Astronomy Picture of the Day

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.
2008 August 21

August Moons
Credit & Copyright: Dennis Mammana (left), Laurent Laveder, TWAN Explanation: This August was eclipse season. The month's first New Moon and Full Moon were both seen in darkened skies during a solar and lunar eclipse. Blocking the Sun, the left panel's New Moon was captured during the total solar eclipse of August 1 from the path of totality overlooking Novosibirsk (Siberia) Reservoir, locally known as the Ob Sea. A lovely solar corona and bright inner planets Mercury and Venus emerged during the total eclipse phase, while the flickering view screens of eclipse watchers' digital cameras dotted the landscape. On the right, the Full Moon grazed Earth's shadow nearly 15 days later in a partial lunar eclipse. That serene view was recorded during an early evening stroll along the shores of the Odet River near the city of Quimper in western France. For planet Earth there are about two seasons each year during which the orientation of the Moon's orbit is favorable for solar and lunar eclipses. The next eclipse season begins in January 2009 with an annular solar eclipse.


Tomorrow's picture: pixels in space

 

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Astronomy Picture of the Day

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.
2008 August 22

Active Galaxy NGC 1275
Credit: NASA, ESA, Hubble Heritage (STScI/AURA);
A. Fabian (IoA, Cambridge U.), L. Frattare (STScI), CXC, G. Taylor, NRAO,VLA Explanation: Active galaxy NGC 1275 is the central, dominant member of the large and relatively nearby Perseus Cluster of Galaxies. A prodigious source of x-rays and radio emission, NGC 1275 accretes matter as entire galaxies fall into it, ultimately feeding a supermassive black hole at the galaxy's core. This stunning visible light image from the Hubble Space Telescope shows galactic debris and filaments of glowing gas, some up to 20,000 light-years long. The filaments persist in NGC 1275, even though the turmoil of galactic collisions should destroy them. What keeps the filaments together? Recent work indicates that the structures, pushed out from the galaxy's center by the black hole's activity, are held together by magnetic fields. To add x-ray data from the Chandra Observatory and radio data from the Very Large Array to the Hubble image, just slide your cursor over the picture. In the resulting composite, x-rays highlight the shells of hot gas surrounding the center of the galaxy, with radio emission filling giant bubble-shaped cavities. Also known as Perseus A, NGC 1275 spans over 100,000 light years and lies about 230 million light years away.


Tomorrow's picture: light-weekend

 

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Astronomy Picture of the Day

Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.
2008 August 23

The Matter of the Bullet Cluster
Composite Credit: X-ray: NASA/CXC/CfA/ M.Markevitch et al.;
Lensing Map: NASA/STScI; ESO WFI; Magellan/U.Arizona/ D.Clowe et al.
Optical: NASA/STScI; Magellan/U.Arizona/D.Clowe et al. Explanation: The matter in galaxy cluster 1E 0657-56, fondly known as the "bullet cluster", is shown in this composite image. A mere 3.4 billion light-years away, the bullet cluster's individual galaxies are seen in the optical image data, but their total mass adds up to far less than the mass of the cluster's two clouds of hot x-ray emitting gas shown in red. Representing even more mass than the optical galaxies and x-ray gas combined, the blue hues show the distribution of dark matter in the cluster. Otherwise invisible to telescopic views, the dark matter was mapped by observations of gravitational lensing of background galaxies. In a text book example of a shock front, the bullet-shaped cloud of gas at the right was distorted during the titanic collision between two galaxy clusters that created the larger bullet cluster itself. But the dark matter present has not interacted with the cluster gas except by gravity. The clear separation of dark matter and gas clouds is considered direct evidence that dark matter exists.


Tomorrow's picture: grand spiral