Η Αστρονομική Εικόνα της Ημέρας από τη NASA
Interplanetary Earth
23/11/2024
In an interplanetary first, on July 19, 2013 Earth was photographed on the same day from two other worlds of the Solar System, innermost planet Mercury and ringed gas giant Saturn. Pictured on the left, Earth is the pale blue dot just below the rings of Saturn, as captured by the robotic Cassini spacecraft then orbiting the outermost gas giant. On that same day people across planet Earth snapped many of their own pictures of Saturn. On the right, the Earth-Moon system is seen against the dark background of space as captured by the sunward MESSENGER spacecraft, then in Mercury orbit. MESSENGER took its image as part of a search for small natural satellites of Mercury, moons that would be expected to be quite dim. In the MESSENGER image, the brighter Earth and Moon are both overexposed and shine brightly with reflected sunlight. Destined not to return to their home world, both Cassini and MESSENGER have since retired from their missions of Solar System exploration.
Copyright: NASA
Προηγούμενες Αστρονομικές Εικόνες της Ημέρας από τη NASA
Full Observatory Moon
27/01/2024
A popular name for January's full moon in the northern hemisphere is the Full Wolf Moon. As the new year's first full moon, it rises over Las Campanas Observatory in this dramatic Earth-and-moonscape. Peering from the foreground like astronomical eyes are the observatory's twin 6.5 meter diameter Magellan telescopes. The snapshot was captured with telephoto lens across rugged terrain in the Chilean Atacama Desert, taken at a distance of about 9 miles from the observatory and about 240,000 miles from the lunar surface. Of course the first full moon of the lunar new year, known to some as the Full Snow Moon, will rise on February 24.
Copyright: Yuri Beletsky
Epsilon Tauri: Star with Planet
26/01/2024
silon Tauri lies 146 light-years away. A K-type red giant star, epsilon Tau is cooler than the Sun, but with about 13 times the solar radius it has nearly 100 times the solar luminosity. A member of the Hyades open star cluster the giant star is known by the proper name Ain, and along with brighter giant star Aldebaran, forms the eyes of Taurus the Bull. Surrounded by dusty, dark clouds in Taurus, epsilon Tau is also known to have a planet. Discovered by radial velocity measurements in 2006, Epsilon Tauri b is a gas giant planet larger than Jupiter with an orbital period of 1.6 years. And though the exoplanet can't be seen directly, on a dark night its parent star epsilon Tauri is easily visible to the unaided eye.
Copyright: Reg Pratt
Jyväskylä in the Sky
25/01/2024
You might not immediately recognize this street map of a neighborhood in Jyväskylä, Finland, planet Earth. But that's probably because the map was projected into the night sky and captured with an allsky camera on January 16. The temperature recorded on that northern winter night was around minus 20 degrees Celsius. As ice crystals formed in the atmosphere overhead, street lights spilling illumination into the sky above produced visible light pillars, their ethereal appearance due to specular reflections from the fluttering crystals' flat surfaces. Of course, the projected light pillars trace a map of the brightly lit local streets, though reversed right to left in the upward looking camera's view. This light pillar street map was seen to hover for hours in the Jyväskylä night.
Copyright: Harri Kiiskinen
Earth and Moon from Beyond
24/01/2024
What do the Earth and Moon look like from beyond the Moon? Although frequently photographed together, the familiar duo was captured with this unusual perspective in late 2022 by the robotic Orion spacecraft of NASA's Artemis I mission as it looped around Earth's most massive satellite and looked back toward its home world. Since our Earth is about four times the diameter of the Moon, the satellite’s seemingly large size was caused by the capsule being closer to the smaller body. Artemis II, the next launch in NASA’s Artemis series, is currently scheduled to take people around the Moon in 2025, while Artemis III is planned to return humans to lunar surface in late 2026. Last week, JAXA's robotic SLIM spacecraft, launched from Japan, landed on the Moon and released two hopping rovers. Explore Your Universe: Random APOD Generator
Copyright: NASA
Deep Nebulas: From Seagull to California
23/01/2024
How well do you know the night sky? OK, but how well can you identify famous sky objects in a very deep image? Either way, here is a test: see if you can find some well-known night-sky icons in a deep image filled with faint nebulosity. This image contains the Pleiades star cluster, Barnard's Loop, Horsehead Nebula, Orion Nebula, Rosette Nebula, Cone Nebula, Rigel, Jellyfish Nebula, Monkey Head Nebula, Flaming Star Nebula, Tadpole Nebula, Aldebaran, Simeis 147, Seagull Nebula and the California Nebula. To find their real locations, here is an annotated image version. The reason this task might be difficult is similar to the reason it is initially hard to identify familiar constellations in a very dark sky: the tapestry of our night sky has an extremely deep hidden complexity. The featured composite reveals some of this complexity in a mosaic of 28 images taken over 800 hours from dark skies over Arizona, USA.
Copyright: Alistair Symon
Shadows of Mountain and Moon
22/01/2024
Can the Moon and a mountain really cast similar shadows? Yes, but the division between light and dark does not have to be aligned. Pictured, a quarter moon was captured above the mountain Grivola in Italy in early October of 2022. The Sun is to the right of the featured picturesque landscape, illuminating the right side of the Moon in a similar way that it illuminates the right side of the mountain. This lunar phase is called "quarter" because the lit fraction visible from Earth is one quarter of the entire lunar surface. Digital post-processing of this single exposure gave both gigantic objects more prominence. Capturing the terminator of this quarter moon in close alignment with nearly vertical mountain ridge required careful timing because the Earth rotates once a day.
Copyright: Enzo Massa Micon
The Upper Michigan Blizzard of 1938
21/01/2024
Yes, but can your blizzard do this? In the Upper Peninsula of Michigan's Storm of the Century in 1938, some snow drifts reached the level of utility poles. Nearly a meter of new and unexpected snow fell over two days in a storm that started 86 years ago this week. As snow fell and gale-force winds piled snow to surreal heights, many roads became not only impassable but unplowable; people became stranded, cars, school buses and a train became mired, and even a dangerous fire raged. Two people were killed and some students were forced to spend several consecutive days at school. The featured image was taken by a local resident soon after the storm. Although all of this snow eventually melted, repeated snow storms like this help build lasting glaciers in snowy regions of our planet Earth.
Copyright: NASA
Falcon Heavy Boostback Burn
20/01/2024
The December 28 night launch of a Falcon Heavy rocket from Kennedy Space Center in Florida marked the fifth launch for the rocket's reusable side boosters. About 2 minutes 20 seconds into the flight, the two side boosters separated from the rocket's core stage. Starting just after booster separation, this three minute long exposure captures the pair's remarkable boostback burns, maneuvers executed prior to their return to landing zones on planet Earth. While no attempt was made to recover the Falcon Heavy's core stage, both side boosters landed successfully and can be flown again. The four previous flights for these side boosters included last October's launch of NASA's asteroid-bound Psyche mission.
Copyright: Dennis Huff
Η Αστρονομική Εικόνα της Ημέρας από τη NASA (NASA Astronomy Picture of the Day) είναι μια δωρεάν υπηρεσία που παρέχει καθημερινά μια εντυπωσιακή εικόνα από το σύμπαν, την λήψη της οποίας έχει πραγματοποιήσει κάποιος από τους αστρονόμους της NASA ή από κάποιον από τους δορυφόρους ή τα τηλεσκόπια που η NASA λειτουργεί. Οι εικόνες που εμφανίζονται καλύπτουν μια ευρεία γκάμα από θέματα, συμπεριλαμβανομένων των αστερισμών, των γαλαξιών, των πλανητικών συστημάτων, των κομητών, των αστρικών σωμάτων και των παρατηρητηρίων. Κάθε εικόνα συνοδεύεται από μια σύντομη εξήγηση και πληροφορίες σχετικά με το τι παρατηρείται στην εικόνα.