Acrobase  

Καλώς ήρθατε στην AcroBase.
Δείτε εδώ τα πιο πρόσφατα μηνύματα από όλες τις περιοχές συζητήσεων, καθώς και όλες τις υπηρεσίες της AcroBase.
H εγγραφή σας είναι γρήγορη και εύκολη.

Επιστροφή   Acrobase > Ελεύθερος Χρόνος και Ψυχαγωγία > Καθημερινά ενημερωτικά θέματα
Ομάδες (Groups) Τοίχος Άρθρα acrobase.org Ημερολόγιο Φωτογραφίες Στατιστικά

Notices

Δεν έχετε δημιουργήσει όνομα χρήστη στην Acrobase.
Μπορείτε να το δημιουργήσετε εδώ

Απάντηση στο θέμα
 
Εργαλεία Θεμάτων Τρόποι εμφάνισης
  #3091  
Παλιά 03-04-15, 08:31
Το avatar του χρήστη Xenios
Xenios Ο χρήστης Xenios δεν είναι συνδεδεμένος
Administrator
 

Τελευταία φορά Online: 12-11-16 10:12
Φύλο: Άντρας
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.
2015 April 2

Sun and Moon Halo
Image Credit & Copyright: Göran Strand
Explanation: Two pictures captured on April 1 are combined in this creative day and night composite. Separated in time by about 10 hours the images otherwise match, looking along the coast at Östersund Sweden. The relative times were chosen to show the Sun and a nearly full Moon at the same place in the cold, early springtime sky. In the night scene Jupiter also shines above the waterfront lights, while Sun and Moon are both surrounded by a beautiful circular ice halo. The Sun and Moon halos really do align, each with an angular radius of 22 degrees. That radius is a constant, not determined by the brightness of Sun or Moon but only by the hexagonal geometry of atmospheric ice crystals and the reflection and refraction of light. Of course tomorrow, April 4, will find the Sun and Moon on opposite sides of planet Earth for a total lunar eclipse.
Tomorrow's picture: light-weekend

Πηγή
__________________
όταν γράφεται η ιστορία της ζωής σου,
μην αφήνεις κανέναν να κρατάει την πένα
Απάντηση με παράθεση
  #3092  
Παλιά 04-04-15, 09:13
Το avatar του χρήστη Xenios
Xenios Ο χρήστης Xenios δεν είναι συνδεδεμένος
Administrator
 

Τελευταία φορά Online: 12-11-16 10:12
Φύλο: Άντρας
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.
2015 April 4

Voorwerpjes in Space
Image Credit: NASA, ESA, William Keel (Univ. Alabama)
Explanation: Mysterious Hanny's Voorwerp, Dutch for "Hanny's Object", is really enormous, about the size of the Milky Way Galaxy and glowing strongly in the greenish light produced by ionized oxygen atoms. It is thought to be a tidal tail of material left by an ancient galaxy merger, illuminated and ionized by the outburst of a quasar inhabiting the center of distant spiral galaxy IC 2497. Its exciting 2007 discovery by Dutch schoolteacher Hanny van Arkel while participating online in the Galaxy Zoo project has since inspired a search and discovery of eight more eerie green cosmic features. Imaged in these panels by the Hubble Space Telescope, all eight appear near galaxies with energetic cores. Far outside their associated galaxies, these objects are also likely echoes of quasar activity, illuminated only as light from a core quasar outburst reaches them and ultimately fading tens of thousands of years after the quasar outburst itself has faded away. Of course a galaxy merger like the impending merger of our own Milky Way and the Andromeda Galaxy, could also trigger the birth of a quasar that would illuminate our distant future version of Hanny's Voorwerp.
Tomorrow's picture: rings and shadows

Πηγή
__________________
όταν γράφεται η ιστορία της ζωής σου,
μην αφήνεις κανέναν να κρατάει την πένα
Απάντηση με παράθεση
  #3093  
Παλιά 05-04-15, 09:10
Το avatar του χρήστη Xenios
Xenios Ο χρήστης Xenios δεν είναι συνδεδεμένος
Administrator
 

Τελευταία φορά Online: 12-11-16 10:12
Φύλο: Άντρας
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.
2015 April 5

Saturn, Tethys, Rings, and Shadows
Image Credit: Cassini Imaging Team, SSI, JPL, ESA, NASA
Explanation: Seen from ice moon Tethys, rings and shadows would display fantastic views of the Saturnian system. Haven't dropped in on Tethys lately? Then this gorgeous ringscape from the Cassini spacecraft will have to do for now. Caught in sunlight just below and left of picture center in 2005, Tethys itself is about 1,000 kilometers in diameter and orbits not quite five saturn-radii from the center of the gas giant planet. At that distance (around 300,000 kilometers) it is well outside Saturn's main bright rings, but Tethys is still one of five major moons that find themselves within the boundaries of the faint and tenuous outer E ring. Discovered in the 1980s, two very small moons Telesto and Calypso are locked in stable locations along Tethys' orbit. Telesto precedes and Calypso follows Tethys as the trio circles Saturn.
Tomorrow's picture: huge balls of light

Πηγή
__________________
όταν γράφεται η ιστορία της ζωής σου,
μην αφήνεις κανέναν να κρατάει την πένα
Απάντηση με παράθεση
  #3094  
Παλιά 07-04-15, 08:28
Το avatar του χρήστη Xenios
Xenios Ο χρήστης Xenios δεν είναι συνδεδεμένος
Administrator
 

Τελευταία φορά Online: 12-11-16 10:12
Φύλο: Άντρας
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.
2015 April 7

In the Heart of the Virgo Cluster
Image Credit: NASA/ESA/ESO/NAOJ/G. Paglioli; Copyright: R. Colombari/G. Paglioli
Explanation: The Virgo Cluster of Galaxies is the closest cluster of galaxies to our Milky Way Galaxy. The Virgo Cluster is so close that it spans more than 5 degrees on the sky - about 10 times the angle made by a full Moon. With its heart lying about 70 million light years distant, the Virgo Cluster is the nearest cluster of galaxies, contains over 2,000 galaxies, and has a noticeable gravitational pull on the galaxies of the Local Group of Galaxies surrounding our Milky Way Galaxy. The cluster contains not only galaxies filled with stars but also gas so hot it glows in X-rays. Motions of galaxies in and around clusters indicate that they contain more dark matter than any visible matter we can see. Pictured above, the heart of the Virgo Cluster includes bright Messier galaxies such as Markarian's Eyes on the upper left, M86 just to the upper right of center, M84 on the far right, as well as spiral galaxy NGC 4388 at the bottom right.
Tomorrow's picture: open space

Πηγή
__________________
όταν γράφεται η ιστορία της ζωής σου,
μην αφήνεις κανέναν να κρατάει την πένα
Απάντηση με παράθεση
  #3095  
Παλιά 08-04-15, 08:44
Το avatar του χρήστη Xenios
Xenios Ο χρήστης Xenios δεν είναι συνδεδεμένος
Administrator
 

Τελευταία φορά Online: 12-11-16 10:12
Φύλο: Άντρας
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.
2015 April 8

Full Moon in Earth's Shadow
Image Credit & Copyright: Rolf Olsen
Explanation: Last week the Full Moon was completely immersed in Earth's dark umbral shadow, just briefly though. The total phase of the April 4, 2015 lunar eclipse lasted less than 5 minutes, the shortest total lunar eclipse of the century. In fact, sliding just within the Earth's umbral shadow's northern edge, the lunar north stayed relatively bright, while a beautiful range of blue and red hues emerged across the rest of the Moon's Earth-facing hemisphere. The reddened light within the shadow that reaches the lunar surface is filtered through the lower atmosphere. Seen from a lunar perspective it comes from all the sunsets and sunrises around the edges of the silhouetted Earth. Close to the shadow's edge, the bluer light is still filtered through Earth's atmosphere, but originates as rays of sunlight pass through layers high in the upper stratosphere. That light is colored by ozone that absorbs red light and transmits bluer hues. In this sharp telescopic view of totality from Auckland, New Zealand, planet Earth, the Moon's north pole has been rotated to the top of the frame.
Tomorrow's picture: pixels in space

Πηγή
__________________
όταν γράφεται η ιστορία της ζωής σου,
μην αφήνεις κανέναν να κρατάει την πένα
Απάντηση με παράθεση
  #3096  
Παλιά 09-04-15, 08:33
Το avatar του χρήστη Xenios
Xenios Ο χρήστης Xenios δεν είναι συνδεδεμένος
Administrator
 

Τελευταία φορά Online: 12-11-16 10:12
Φύλο: Άντρας
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.
2015 April 9

A Golden Gate Eclipse
Image Credit & Copyright: Rogelio Bernal Andreo (Deep Sky Colors)
Explanation: Shadows play on the water and in the sky in this panoramic view of the April 4 total lunar eclipse over San Francisco's Golden Gate Bridge. Just within planet Earth's shadow the Full Moon's disk is still easy to spot at its brief total phase. The urban night skyscape was composed to cover the wide range of brightness visible to the eye. The shortest total lunar eclipse of the century, this eclipse was also the third in a string of four consecutive total lunar eclipses, a series known as a tetrad. Coming in nearly six month intervals, the previous two were last April 15 and October 8. The next and final eclipse in the tetrad will be on September 28. This 2014-2015 tetrad is one of 8 total lunar eclipse tetrads in the 21st century.
Tomorrow's picture: pixels in space

Πηγή
__________________
όταν γράφεται η ιστορία της ζωής σου,
μην αφήνεις κανέναν να κρατάει την πένα
Απάντηση με παράθεση
  #3097  
Παλιά 10-04-15, 08:22
Το avatar του χρήστη Xenios
Xenios Ο χρήστης Xenios δεν είναι συνδεδεμένος
Administrator
 

Τελευταία φορά Online: 12-11-16 10:12
Φύλο: Άντρας
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.
2015 April 10

NGC 2903: A Missing Jewel in Leo
Image Credit & Copyright: Tony Hallas
Explanation: Barred spiral galaxy NGC 2903 is only some 20 million light-years distant. Popular among amateur astronomers, it shines in the northern spring constellation Leo, near the top of the lion's head. That part of the constellation is sometimes seen as a reversed question mark or sickle. One of the brighter galaxies visible from the northern hemisphere, NGC 2903 is surprisingly missing from Charles Messier's catalog of lustrous celestial sights. This colorful image from a small ground-based telescope shows off the galaxy's gorgeous spiral arms traced by young, blue star clusters and pinkish star forming regions. Included are intriguing details of NGC 2903's bright core, a remarkable mix of old and young clusters with immense dust and gas clouds. In fact, NGC 2903 exhibits an exceptional rate of star formation activity near its center, also bright in radio, infrared, ultraviolet, and x-ray bands. Just a little smaller than our own Milky Way, NGC 2903 is about 80,000 light-years across.
Tomorrow's picture: Venus in the west

Πηγή
__________________
όταν γράφεται η ιστορία της ζωής σου,
μην αφήνεις κανέναν να κρατάει την πένα
Απάντηση με παράθεση
  #3098  
Παλιά 11-04-15, 09:06
Το avatar του χρήστη Xenios
Xenios Ο χρήστης Xenios δεν είναι συνδεδεμένος
Administrator
 

Τελευταία φορά Online: 12-11-16 10:12
Φύλο: Άντρας
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.
2015 April 11

Venus in the West
Image Credit & Copyright: Babak Tafreshi (TWAN)
Explanation: In the coming days, Venus shines near the western horizon at sunset. To find Earth's sister planet in twilight skies just look for the brilliant evening star. Tonight very close to the Pleiades star cluster, Venus dominates this springtime night skyscape taken only a few days ago near the town of Lich in central Germany. Also known as the Seven Sisters, the stars of the compact Pleiades cluster appear above Venus in this picture. The budding tree branches to its left frame bright star Aldebaran, the eye of Taurus the Bull, and the V-shaped Hyades star cluster.
Tomorrow's picture: Sunday's Childe

Πηγή
__________________
όταν γράφεται η ιστορία της ζωής σου,
μην αφήνεις κανέναν να κρατάει την πένα
Απάντηση με παράθεση
  #3099  
Παλιά 12-04-15, 09:07
Το avatar του χρήστη Xenios
Xenios Ο χρήστης Xenios δεν είναι συνδεδεμένος
Administrator
 

Τελευταία φορά Online: 12-11-16 10:12
Φύλο: Άντρας
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.
2015 April 12

Sentinels of the Arctic
Image Credit & Copyright: Niccolò Bonfadini
Explanation: Who guards the north? Judging from the above photograph, possibly giant trees covered in snow and ice. The featured picture was taken a few winters ago in Finnish Lapland where weather can include sub-freezing temperatures and driving snow. Surreal landscapes sometimes result, where common trees become cloaked in white and so appear, to some, as watchful aliens. Far in the distance, behind this uncommon Earthly vista, is a more common sight -- a Belt of Venus that divided a darkened from sunlit sky as the Sun rose behind the photographer. Of course, in the spring, the trees thaw and Lapland looks much different.
Follow APOD on: Facebook, Google Plus, or Twitter
Tomorrow's picture: in the distance

Πηγή
__________________
όταν γράφεται η ιστορία της ζωής σου,
μην αφήνεις κανέναν να κρατάει την πένα
Απάντηση με παράθεση
  #3100  
Παλιά 13-04-15, 10:04
Το avatar του χρήστη Xenios
Xenios Ο χρήστης Xenios δεν είναι συνδεδεμένος
Administrator
 

Τελευταία φορά Online: 12-11-16 10:12
Φύλο: Άντρας
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.
2015 April 13

Milky Way over Erupting Volcano
Image Credit & Copyright: Sergio Montúfar
Explanation: The view was worth the trip. Battling high winds, cold temperatures, and low oxygen, the trek to near the top of the volcano Santa Maria in Guatemala -- while carrying sensitive camera equipment -- was lonely and difficult. Once set up, though, the camera captured this breathtaking vista during the early morning hours of February 28. Visible on the ground are six volcanoes of the Central America Volcanic Arc, including Fuego, the Volcano of Fire, which is seen erupting in the distance. Visible in the sky, in separate exposures taken a few minutes later, are many stars much further in the distance, as well as the central band of our Milky Way Galaxy situated horizontally overhead.
Tomorrow's picture: through the shadow of the moon

Πηγή
__________________
όταν γράφεται η ιστορία της ζωής σου,
μην αφήνεις κανέναν να κρατάει την πένα
Απάντηση με παράθεση
  #3101  
Παλιά 14-04-15, 09:20
Το avatar του χρήστη Xenios
Xenios Ο χρήστης Xenios δεν είναι συνδεδεμένος
Administrator
 

Τελευταία φορά Online: 12-11-16 10:12
Φύλο: Άντρας
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.
2015 April 14


Through the Shadow of the Moon
Video Credit & Copyright: Stephan Heinsius (Eclipseland)
Explanation: What would it look like to fly through a total eclipse of the Sun? On a typical place on Earth in the path of the dark shadow of the Moon during a total eclipse, an observer would see the Moon cross the face of the Sun, completely blocking it for a few minutes. A particularly clear view of the darkness created on Earth during last month's total solar eclipse was captured by an aircraft flying through the Moon's umbral shadow. One second of time in the featured time-lapse video corresponds to about one minute of real time. The Moon's shadow comes in from the right and leaves on the left, all while locations on Earth outside the umbral shadow -- over 100 kilometers away -- remain partly sunlit. During the next solar eclipse in mid-September, the Moon will, at most, block only part of the Sun.
Tomorrow's picture: open space

Πηγή
__________________
όταν γράφεται η ιστορία της ζωής σου,
μην αφήνεις κανέναν να κρατάει την πένα
Απάντηση με παράθεση
  #3102  
Παλιά 15-04-15, 09:06
Το avatar του χρήστη Xenios
Xenios Ο χρήστης Xenios δεν είναι συνδεδεμένος
Administrator
 

Τελευταία φορά Online: 12-11-16 10:12
Φύλο: Άντρας
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.
2015 April 15

Mystic Mountain Dust Pillars
Image Credit: Hubble Legacy Archive, NASA, ESA; Processing & Copyright: David Forteza
Explanation: It's stars versus dust in the Carina Nebula and the stars are winning. More precisely, the energetic light and winds from massive newly formed stars are evaporating and dispersing the dusty stellar nurseries in which they formed. Located in the Carina Nebula and known informally as Mystic Mountain, these pillar's appearance is dominated by the dark dust even though it is composed mostly of clear hydrogen gas. Dust pillars such as these are actually much thinner than air and only appear as mountains due to relatively small amounts of opaque interstellar dust. About 7,500 light-years distant, the featured image was taken with the Hubble Space Telescope, digitally reprocessed by an industrious amateur, and highlights an interior region of Carina which spans about three light years. Within a few million years, the stars will likely win out completely and the entire dust mountain will be destroyed.
Did you Know: This week is International Dark Sky Week?
Tomorrow's picture: open space

Πηγή
__________________
όταν γράφεται η ιστορία της ζωής σου,
μην αφήνεις κανέναν να κρατάει την πένα
Απάντηση με παράθεση
  #3103  
Παλιά 16-04-15, 08:50
Το avatar του χρήστη Xenios
Xenios Ο χρήστης Xenios δεν είναι συνδεδεμένος
Administrator
 

Τελευταία φορά Online: 12-11-16 10:12
Φύλο: Άντρας
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.
2015 April 16

One-Armed Spiral Galaxy NGC 4725
Image Credit & Copyright: Martin Pugh
Explanation: While most spiral galaxies, including our own Milky Way, have two or more spiral arms, NGC 4725 has only one. In this sharp color composite image, the solo spira mirabilis seems to wind from a prominent ring of bluish, newborn star clusters and red tinted star forming regions. The odd galaxy also sports obscuring dust lanes a yellowish central bar structure composed of an older population of stars. NGC 4725 is over 100 thousand light-years across and lies 41 million light-years away in the well-groomed constellation Coma Berenices. Computer simulations of the formation of single spiral arms suggest that they can be either leading or trailing arms with respect to a galaxy's overall rotation. Also included in the frame, sporting a noticably more traditional spiral galaxy look, is a more distant background galaxy.
Tomorrow's picture: pixels in space

Πηγή
__________________
όταν γράφεται η ιστορία της ζωής σου,
μην αφήνεις κανέναν να κρατάει την πένα
Απάντηση με παράθεση
  #3104  
Παλιά 17-04-15, 08:28
Το avatar του χρήστη Xenios
Xenios Ο χρήστης Xenios δεν είναι συνδεδεμένος
Administrator
 

Τελευταία φορά Online: 12-11-16 10:12
Φύλο: Άντρας
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.
2015 April 17

M46 Plus Two
Image Credit & Copyright: Denis Priou
Explanation: Galactic or open star clusters are young. These swarms of stars are born together near the plane of the Milky Way, but their numbers steadily dwindle as cluster members are ejected by galactic tides and gravitational interactions. In fact, this bright open cluster, known as M46, is around 300 million years young. It still contains a few hundred stars within a span of 30 light-years or so. Located about 5,000 light-years away toward the constellation Puppis, M46 also seems to contain contradictions to its youthful status. In this pretty starscape, the colorful, circular patch above and right of the center of M46 is the planetary nebula NGC 2438. Fainter still, a second planetary nebula, PK231+4.1, is identified by the box at the right and enlarged in the inset. Planetary nebulae are a brief, final phase in the life of a sun-like star a billion years old or more, whose central reservoir of hydrogen fuel has been exhausted. NGC 2438 is estimated to be only 3,000 light-years distant, though, and moves at a different speed than M46 cluster members. Along with its fainter cohort, planetary nebula NGC 2438 is likely only by chance appearing near our line-of-sight to the young stars of M46.
Tomorrow's picture: central peaks, beautiful terraces, and frozen seas

Πηγή
__________________
όταν γράφεται η ιστορία της ζωής σου,
μην αφήνεις κανέναν να κρατάει την πένα
Απάντηση με παράθεση
  #3105  
Παλιά 18-04-15, 08:28
Το avatar του χρήστη Xenios
Xenios Ο χρήστης Xenios δεν είναι συνδεδεμένος
Administrator
 

Τελευταία φορά Online: 12-11-16 10:12
Φύλο: Άντρας
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.
2015 April 18

The Great Crater Hokusai
Image Credit: NASA, Johns Hopkins Univ. APL, Arizona State Univ., CIW
Explanation: One of the largest young craters on Mercury, 114 kilometer (71 mile) diameter Hokusai crater's bright rays are known to extend across much of the planet. But this mosaic of oblique views focuses on Hokusai close up, its sunlit central peaks, terraced crater walls, and frozen sea of impact melt on the crater's floor. The images were captured by the MESSENGER spacecraft. The first to orbit Mercury, since 2011 MESSENGER has conducted scientific explorations, including extensive imaging of the Solar System's innermost planet. Now running out of propellant and unable to counter orbital perturbations caused by the Sun's gravity, MESSENGER is predicted to impact the surface of Mercury on April 30.
Tomorrow's picture: ringing hubble

Πηγή
__________________
όταν γράφεται η ιστορία της ζωής σου,
μην αφήνεις κανέναν να κρατάει την πένα
Απάντηση με παράθεση
Απάντηση στο θέμα


Συνδεδεμένοι χρήστες που διαβάζουν αυτό το θέμα: 2 (0 μέλη και 2 επισκέπτες)
 
Εργαλεία Θεμάτων
Τρόποι εμφάνισης

Δικαιώματα - Επιλογές
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is σε λειτουργία
Τα Smilies είναι σε λειτουργία
Ο κώδικας [IMG] είναι σε λειτουργία
Ο κώδικας HTML είναι σε λειτουργία

Που θέλετε να σας πάμε;


Όλες οι ώρες είναι GMT +3. Η ώρα τώρα είναι 02:02.



Forum engine powered by : vBulletin Version 3.8.2
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.