Astronomy Picture of The Day الصورة الفلكية اليومية

رحل اليوم عن عالمنا "ستيفن هوكينج " . انسان كان مثالاً في التحدي و الأكثر قدرته على إيصال المعلومات الفيزيائية للعامة فقد ألف أشهر الكتب في الفيزياء في هذا المجال و هي:
- تاريخ موجز للزمن 1988
- الثقوب السوداء والأكوان الناشئة 1993
- الكون في قشرة جوز 2001
- الوقوف على أكتاف العمالقة 2002
- تاريخ أكثر إيجازا للزمن 2005
- الله خلق الأرقام 2005
- التصميم العظيم 2010
- تاريخي الموجز 2013

Sadly we have to say "Goodbye" to this unbelievable man "Stephen Hawking"
who in my opinion his greet influence was in spread modern physical ideas through his great books:

- A Brief History of Time (1988)[194]
-Black Holes and Baby Universes and Other Essays (1993)[356]
-The Universe in a Nutshell (2001)
-On The Shoulders of Giants (2002)
-God Created the Integers: The Mathematical Breakthroughs That Changed History (2005)
-The Dreams That Stuff Is Made of: The Most Astounding Papers of Quantum Physics and How They Shook the -Scientific World (2011)
- My Brief History (2013)

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Image may contain: 1 person

01-09-2017
A First Glimpse of the Great American Eclipse


Image Credit & Copyright: Babak Tafreshi (TWAN)

Explanation: Making landfall in Oregon, the Moon's dark umbral shadow toured the United States on August 21. Those gathered along its coast to coast path were witness to a total eclipse of the Sun, possibly the most widely shared celestial event in history. But first, the Moon's shadow touched the northern Pacific and raced eastward toward land. This dramatic snapshot was taken while crossing the shadow path 250 miles off the Oregon coast, 45,000 feet above the cloudy northern Pacific. Though from a shorter totality, it captures the eclipse before it could be seen from the US mainland. With the eclipsed Sun not far above, beautiful colors appear along the western horizon giving way to a clear, pitch-black, stratospheric sky in the shadow of the Moon.

04-01-2017
Clouds of Andromeda
Image Credit & Copyright: Rogelio Bernal Andreo (Deep Sky Colors)
Explanation: The beautiful Andromeda Galaxy is often imaged by planet Earth-based astronomers. Also known as M31, the nearest large spiral galaxy is a familiar sight with dark dust lanes, bright yellowish core, and spiral arms traced by blue starlight. A mosaic of well-exposed broad and narrow-band image data, this colorful, premier portrait of our neighboring island universe offers strikingly unfamiliar features though, faint reddish clouds of glowing ionized hydrogen gas in the same wide field of view. Still, the ionized hydrogen clouds likely lie in the foreground of the scene, well within our Milky Way Galaxy. They could be associated with the pervasive, dusty interstellar cirrus clouds scattered hundreds of light-years above our own galactic plane. If they were located at the 2.5 million light-year distance of the Andromeda Galaxy they would be enormous, since the Andromeda Galaxy itself is 200,000 or so light-years across.

https://apod.nasa.gov/apod/ap170104.html

03-03-2017

Pandora Close-up at Saturn
Image Credit: NASA, JPL-Caltech, Space Science Institute
Explanation: What do the craters of Saturn's small moon Pandora look like up close? To help find out, NASA sent the robotic Cassini spacecraft, now orbiting Saturn, past the unusual moon two weeks ago. The highest resolution image of Pandora ever taken was then captured from about 40,000 kilometers out and is featured here. Structures as small as 300 meters can be discerned on 80-kilometer wide Pandora. Craters on Pandora appear to be covered over by some sort of material, providing a more smooth appearance than sponge-like Hyperion, another small moon of Saturn. Curious grooves and ridges also appear to cross the surface of the small moon. Pandora is partly interesting because, along with its companion moon Prometheus, it helps shepherd the particles of Saturn's F ring into a distinct ring.

https://apod.nasa.gov/apod/ap170103.html

02-02-2017

Comet 45P Returns
Image Credit & Copyright: Fritz Helmut Hemmerich
Explanation: An old comet has returned to the inner Solar System. Not only is Comet 45P/Honda–Mrkos–Pajdušáková physically ancient, it was first discovered 13 orbits ago in 1948. Comet 45P spends most of its time out near the orbit of Jupiter and last neared the Sun in 2011. Over the past few months, however, Comet 45P's new sunward plummet has brightened it considerably. Two days ago, the comet passed the closest part of its orbit to the Sun. The comet is currently visible with binoculars over the western horizon just after sunset, not far from the much brighter planet Venus. Pictured, Comet 45P was captured last week sporting a long ion tail with impressive structure. Comet 45P will pass relatively close to the Earth early next month.

https://apod.nasa.gov/apod/ap170102.html

سنة جديدة
أمل جديد

new year
new hope

01-01-2017

A Full Sky Aurora Over Norway
Image Credit & Copyright: Sebastian Voltmer
Explanation: Higher than the highest building, higher than the highest mountain, higher than the highest airplane, lies the realm of the aurora. Auroras rarely reach below 60 kilometers, and can range up to 1000 kilometers. Aurora light results from energetic electrons and protons striking molecules in the Earth's atmosphere. Frequently, when viewed from space, a complete aurora will appear as a circle around one of the Earth's magnetic poles. The featured wide-angle image, horizontally compressed, captured an unexpected auroral display that stretched across the sky five years ago over eastern Norway.

https://apod.nasa.gov/apod/ap170101.html

11-02-2016
LIGO Detects Gravitational Waves from Merging Black Holes
Illustration Credit: LIGO, NSF, Aurore Simonnet (Sonoma State U.)
http://apod.nasa.gov/apod/ap160211.html

Explanation: Gravitational radiation has been directly detected. The first-ever detection was made by both facilities of the Laser Interferometer Gravitational-Wave Observatory (LIGO) in Washington and Louisiana simultaneously last September. After numerous consistency checks, the resulting 5-sigma discovery was published today. The measured gravitational waves match those expected from two large black holes merging after a death spiral in a distant galaxy, with the resulting new black hole momentarily vibrating in a rapid ringdown. A phenomenon predicted by Einstein, the historic discovery confirms a cornerstone of humanity's understanding of gravity and basic physics. It is also the most direct detection of black holes ever. The featured illustration depicts the two merging black holes with the signal strength of the two detectors over 0.3 seconds superimposed across the bottom. Expected future detections by Advanced LIGO and other gravitational wave detectors may not only confirm the spectacular nature of this measurement but hold tremendous promise of giving humanity a new way to see and explore our universe.

10-02-2016
Galaxies in the River
Image Credit & Copyright: CEDIC Team - Processing: Markus Blauensteiner
http://apod.nasa.gov/apod/ap160210.html

Explanation: Large galaxies grow by eating small ones. Even our own galaxy practices galactic cannibalism, absorbing small galaxies that get too close and are captured by the Milky Way's gravity. In fact, the practice is common in the universe and illustrated by this striking pair of interacting galaxies from the banks of the southern constellation Eridanus, The River. Located over 50 million light years away, the large, distorted spiral NGC 1532 is seen locked in a gravitational struggle with dwarf galaxy NGC 1531 (right of center), a struggle the smaller galaxy will eventually lose. Seen edge-on, spiral NGC 1532 spans about 100,000 light-years. Nicely detailed in this sharp image, the NGC 1532/1531 pair is thought to be similar to the well-studied system of face-on spiral and small companion known as M51.

08-02-2016
Light Pillars over Alaska
Image Credit & Copyright: Allisha Libby
http://apod.nasa.gov/apod/ap160208.html

Explanation: What's happening behind those houses? Pictured here are not auroras but nearby light pillars, a nearby phenomenon that can appear as a distant one. In most places on Earth, a lucky viewer can see a Sun-pillar, a column of light appearing to extend up from the Sun caused by flat fluttering ice-crystals reflecting sunlight from the upper atmosphere. Usually these ice crystals evaporate before reaching the ground. During freezing temperatures, however, flat fluttering ice crystals may form near the ground in a form of light snow, sometimes known as a crystal fog. These ice crystals may then reflect ground lights in columns not unlike a Sun-pillar. The featured image was taken in Fort Wainwright near Fairbanks in central Alaska.