ภาพเด่นประจำวัน NASA 2014-09-01

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 September 1
See Explanation.  Clicking on the picture will download the highest resolution version available.

Airglow Ripples over Tibet
Image Credit & Copyright: Jeff Dai

อธิบาย

คำอธิบายภาษาไทยกำลังอยู่ในระหว่างการแปล โปรดกลับเข้ามาชมใหม่อีกครั้งในภายหลัง

< | Thai mirror hosted by NARIT, translated by NARIT | >


Explanation: Why would the sky look like a giant target? Airglow. Following a giant thunderstorm over Bangladesh in late April, giant circular ripples of glowing air appeared over Tibet, China, as pictured above. The unusual pattern is created by atmospheric gravity waves, waves of alternating air pressure that can grow with height as the air thins, in this case about 90 kilometers up. Unlike auroras 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. More typically seen near the horizon, airglow keeps the night sky from ever being completely dark.

Now Available: APOD 2015 Wall Calendars
Tomorrow's picture: spacetime microscope


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Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (UMCP)
NASA Official: Phillip Newman Specific rights apply.
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& Michigan Tech. U.

ภาพเด่นประจำวัน NASA 2014-09-02

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 September 2
See Explanation.  Clicking on the picture will download the highest resolution version available.

Holometer: A Microscope into Space and Time
Image Credit: C. Hogan, Fermilab

อธิบาย

คำอธิบายภาษาไทยกำลังอยู่ในระหว่างการแปล โปรดกลับเข้ามาชมใหม่อีกครั้งในภายหลัง

< | Thai mirror hosted by NARIT, translated by NARIT | >


Explanation: How different are space and time at very small scales? To explore the unfamiliar domain of the miniscule Planck scale -- where normally unnoticeable quantum effects might become dominant -- a newly developed instrument called the Fermilab Holometer has begun operating at the Fermi National Accelerator Laboratory (Fermilab) near Chicago, Illinois, USA. The instrument seeks to determine if slight but simultaneous jiggles of a mirror in two directions expose a fundamental type of holographic noise that always exceeds a minimum amount. Pictured above is one of the end mirrors of a Holometer prototype. Although the discovery of holographic noise would surely be groundbreaking, the dependence of such noise on a specific laboratory length scale would surprise some spacetime enthusiasts. One reason for this is the Lorentz Invariance postulate of Einstein's special relativity, which states that all length scales should appear contracted to a relatively moving observer -- even the diminutive Planck length. Still, the experiment is unique and many are curious what the results will show.

Astrophysicists: Browse 900+ codes in the Astrophysics Source Code Library
Tomorrow's picture: stars of the butterfly


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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.

ภาพเด่นประจำวัน NASA 2014-09-03

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 September 3
See Explanation.  Clicking on the picture will download the highest resolution version available.

M6: The Butterfly Cluster
Image Credit & Copyright: Marco Lorenzi

อธิบาย

คำอธิบายภาษาไทยกำลังอยู่ในระหว่างการแปล โปรดกลับเข้ามาชมใหม่อีกครั้งในภายหลัง

< | Thai mirror hosted by NARIT, translated by NARIT | >


Explanation: To some, the outline of the open cluster of stars M6 resembles a butterfly. M6, also known as NGC 6405, spans about 20 light-years and lies about 2,000 light years distant. M6, pictured above, can best be seen in a dark sky with binoculars towards the constellation of the Scorpion (Scorpius), coving about as much of the sky as the full moon. Like other open clusters, M6 is composed predominantly of young blue stars, although the brightest star is nearly orange. M6 is estimated to be about 100 million years old. Determining the distance to clusters like M6 helps astronomers calibrate the distance scale of the universe.

Now Available: APOD 2015 Wall Calendars
Tomorrow's picture: open space


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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.

ภาพเด่นประจำวัน NASA 2014-09-04

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 September 4
See Explanation.  Clicking on the picture will download the highest resolution version available.

Cloud, Clusters and Comet Siding Spring
Image Credit & Copyright: Rolando Ligustri (CARA Project, CAST)

อธิบาย

คำอธิบายภาษาไทยกำลังอยู่ในระหว่างการแปล โปรดกลับเข้ามาชมใหม่อีกครั้งในภายหลัง

< | Thai mirror hosted by NARIT, translated by NARIT | >


Explanation: On October 19th, a good place to watch Comet Siding Spring will be from Mars. Then, this inbound visitor (C/2013 A1) to the inner solar system, discovered in January 2013 by Robert McNaught at Australia's Siding Spring Observatory, will pass within 132,000 kilometers of the Red Planet. That's a near miss, equivalent to just over 1/3 the Earth-Moon distance. Great views of the comet for denizens of planet Earth's southern hemisphere are possible now, though. This telescopic snapshot from August 29 captured the comet's whitish coma and arcing dust tail sweeping through southern skies. The fabulous field of view includes, the Small Magellanic Cloud and globular star clusters 47 Tucanae (right) and NGC 362 (upper left). Worried about all those spacecraft in Martian orbit? Streaking dust particles from the comet could pose a danger and controllers plan to position Mars orbiters on the opposite side of the planet during the comet's close flyby.

Tomorrow's picture: Sagittarius mosaic


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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.

ภาพเด่นประจำวัน NASA 2014-09-05

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 September 5
See Explanation.  Clicking on the picture will download the highest resolution version available.

A Sagittarius Starscape
Image Credit & Copyright: Terry Hancock (Down Under Observatory)

อธิบาย

คำอธิบายภาษาไทยกำลังอยู่ในระหว่างการแปล โปรดกลับเข้ามาชมใหม่อีกครั้งในภายหลัง

< | Thai mirror hosted by NARIT, translated by NARIT | >


Explanation: This rich starscape spans nearly 7 degrees on the sky, toward the Sagittarius spiral arm and the center of our Milky Way galaxy. A telescopic mosaic, it features well-known bright nebulae and star clusters cataloged by 18th century cosmic tourist Charles Messier. Still popular stops for skygazers M16, the Eagle (far right), and M17, the Swan (near center) nebulae are the brightest star-forming emission regions. With wingspans of 100 light-years or so, they shine with the telltale reddish glow of hydrogen atoms from over 5,000 light-years away. Colorful open star cluster M25 near the upper left edge of the scene is closer, a mere 2,000 light-years distant and about 20 light-years across. M24, also known as the Sagittarius Star Cloud, crowds in just left of center along the bottom of the frame, fainter and more distant Milky Way stars seen through a narrow window in obscuring fields of interstellar dust.

Tomorrow's picture: light-weekend


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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.