jueves, 30 de octubre de 2014

APOD - A Spectre in the Eastern Veil

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.

2014 October 30
See Explanation.  Clicking on the picture will download   the highest resolution version available.

A Spectre in the Eastern Veil
Image Credit & Copyright: Ken Crawford (Rancho Del Sol Observatory)

Explanation: Frightening forms and scary faces are a mark of the Halloween season. They also haunt this cosmic close-up of the eastern Veil Nebula. The Veil Nebula itself is a large supernova remnant, the expanding debris cloud from the death explosion of a massive star. While the Veil is roughly circular in shape and covers nearly 3 degrees on the sky in the constellation Cygnus, this portion of the eastern Veil spans only 1/2 degree, about the apparent size of the Moon. That translates to 12 light-years at the Veil's estimated distance, a reassuring 1,400 light-years from planet Earth. In the composite of image data recorded through broad and narrow band filters, emission from hydrogen atoms in the remnant is shown in red with strong emission from oxygen atoms in blue-green hues. Of course, in the western part of the Veil lies another seasonal apparition, the Witch's Broom.

Tomorrow's picture: haunting devils tower


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Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (UMCP)
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miércoles, 29 de octubre de 2014

APOD - Iridescent Cloud Edge Over Colorado

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.

2014 October 29
See Explanation.  Clicking on the picture will download   the highest resolution version available.

Iridescent Cloud Edge Over Colorado
Image Credit & Copyright: Phil Plait (Bad Astronomy Blog, Slate)

Explanation: Sometimes your eclipse viewing goes bad in an interesting way. While watching and photographing last Thursday's partial solar eclipse, a popular astronomy blogger suffered through long periods of clouds blocking the Sun. Unexpectedly, however, a nearby cloud began to show a rare effect: iridescence. Frequently part of a more familiar solar corona effect, iridescence is the diffraction of sunlight around a thin screen of nearly uniformly-sized water droplets. Different colors of the sunlight become deflected by slightly different angles and so come to the observer from slightly different directions. This display, featured here, was quite bright and exhibited an unusually broad range of colors. On the right, the contrails of an airplane are also visible.

APOD Wall Calendar: Weather and Volcanoes
Tomorrow's picture: spooky sky


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Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (UMCP)
NASA Official: Phillip Newman Specific rights apply.
NASA Web Privacy Policy and Important Notices
A service of: ASD at NASA / GSFC
& Michigan Tech. U.


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martes, 28 de octubre de 2014

APOD - Retrograde Mars

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.

2014 October 28

See Explanation.  Moving the cursor over the image will bring up an annotated version.  Clicking on the image will bring up the highest resolution version  available.

Retrograde Mars
Credit & Copyright: Tunç Tezel (TWAN)

Explanation: Why would Mars appear to move backwards? Most of the time, the apparent motion of Mars in Earth's sky is in one direction, slow but steady in front of the far distant stars. About every two years, however, the Earth passes Mars as they orbit around the Sun. During the most recent such pass starting late last year, Mars as usual, loomed large and bright. Also during this time, Mars appeared to move backwards in the sky, a phenomenon called retrograde motion. Featured here is a series of images digitally stacked so that all of the stars coincide. Here, Mars appears to trace out a narrow loop in the sky. At the center of the loop, Earth passed Mars and the retrograde motion was the highest. Retrograde motion can also be seen for other Solar System planets.

APOD Wall Calendar: Moons and Planets
Tomorrow's picture: sun block


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Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (UMCP)
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lunes, 27 de octubre de 2014

APOD - Plane, Clouds, Moon, Spots, Sun

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.

2014 October 27
See Explanation.  Clicking on the picture will download   the highest resolution version available.

Plane, Clouds, Moon, Spots, Sun
Image Credit & Copyright: Doyle Slifer

Explanation: What's that in front of the Sun? The closest object is an airplane, visible just below the Sun's center and caught purely by chance. Next out are numerous clouds in Earth's atmosphere, creating a series of darkened horizontal streaks. Farther out is Earth's Moon, seen as the large dark circular bite on the upper right. Just above the airplane and just below the Sun's surface are sunspots. The main sunspot group captured here, AR 2192, is one of the largest ever recorded and has been crackling and bursting with flares since it came around the edge of the Sun early last week. Taken last Thursday, this show of solar silhouettes was unfortunately short-lived. Within a few seconds the plane flew away. Within a few minutes the clouds drifted off. Within a few hours the partial solar eclipse of the Sun by the Moon was over. Only the sunspot group remains, but within a few more days even AR 2192 will disappear around the edge of the Sun. Fortunately, when it comes to the Sun, even unexpected alignments are surprisingly frequent.

Gallery: Last Thursday's Partial Solar Eclipse
Tomorrow's picture: mars, backwards


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Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (UMCP)
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domingo, 26 de octubre de 2014

APOD - Too Close to a Black Hole

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.

2014 October 26
See Explanation.  Clicking on the picture will download   the highest resolution version available.

Too Close to a Black Hole
Image Credit & Copyright: Alain Riazuelo

Explanation: What would you see if you went right up to a black hole? Featured is a computer generated image highlighting how strange things would look. The black hole has such strong gravity that light is noticeably bent towards it - causing some very unusual visual distortions. Every star in the normal frame has at least two bright images - one on each side of the black hole. Near the black hole, you can see the whole sky - light from every direction is bent around and comes back to you. The original background map was taken from the 2MASS infrared sky survey, with stars from the Henry Draper catalog superposed. Black holes are thought to be the densest state of matter, and there is indirect evidence for their presence in stellar binary systems and the centers of globular clusters, galaxies, and quasars.

Gallery: Thursday's Partial Solar Eclipse
Tomorrow's picture: crescent sun


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Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (UMCP)
NASA Official: Phillip Newman Specific rights apply.
NASA Web Privacy Policy and Important Notices
A service of: ASD at NASA / GSFC
& Michigan Tech. U.


This is an automated email. If you notice any problems, just send me a note at gtracy@gmail.com. You can add and remove email addresses to this distribution list here, http://apodemail.org.