Explanation: Spiral galaxy pair NGC 4567 and NGC 4568 share this sharp cosmic vista with lonely elliptical galaxy NGC 4564. All are members of the large Virgo Galaxy Cluster. With their classic spiral arms, dust lanes, and star clusters, the eye-catching spiral pair is also known as the Butterfly Galaxies or the Siamese Twins. Very close together, the galaxy twins don't seem to be too distorted by gravitational tides. Their giant molecular clouds are known to be colliding though and are likely fueling the formation of massive star clusters. The galaxy twins are about 52 million light-years distant, while their bright cores appear separated by about 20,000 light-years. Of course, the spiky foreground stars lie within our own Milky Way.
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01/02/2019
Science & Technology - Astronomy picture of the day - 2019 February 1 : Twin Galaxies in Virgo
31/01/2019
Science & Technology - Astronomy picture of the day - 2019 January 31 : Sharpless 308: Star Bubble
Image Credit & Copyright: Laubing
Explanation: Blown by fast winds from a hot, massive star, this cosmic bubble is huge. Cataloged as Sharpless 2-308 it lies some 5,200 light-years away toward the constellation of the Big Dog (Canis Major) and covers slightly more of the sky than a Full Moon. That corresponds to a diameter of 60 light-years at its estimated distance. The massive star that created the bubble, a Wolf-Rayet star, is the bright one near the center of the nebula. Wolf-Rayet stars have over 20 times the mass of the Sun and are thought to be in a brief, pre-supernova phase of massive star evolution. Fast winds from this Wolf-Rayet star create the bubble-shaped nebula as they sweep up slower moving material from an earlier phase of evolution. The windblown nebula has an age of about 70,000 years. Relatively faint emission captured in the expansive image is dominated by the glow of ionized oxygen atoms mapped to a blue hue. SH2-308 is also known as The Dolphin Nebula.
30/01/2019
Science & Technology - Astronomy picture of the day - 2019 January 30 : From the Northern to the Southern Cross
Explanation: There is a road that connects the Northern to the Southern Cross but you have to be at the right place and time to see it. The road, as pictured here, is actually the central band of our Milky Way Galaxy; the right place, in this case, is dark Laguna Cejar in Salar de Atacama of Northern Chile; and the right time was in early October, just after sunset. Many sky wonders were captured then, including the bright Moon, inside the Milky Way arch; Venus, just above the Moon; Saturn and Mercury, just below the Moon; the Large and Small Magellanic Clouds satellite galaxies, on the far left; red airglow near the horizon on the image left; and the lights of small towns at several locations across the horizon. One might guess that composing this 30-image panorama would have been a serene experience, but for that one would have required earplugs to ignore the continued brays of wild donkeys.
29/01/2019
28/01/2019
Science & Technology - Astronomy picture of the day - 2019 January 28 : Orion over the Austrian Alps
Image Credit & Copyright: Lukáš Veselý
Explanation: Do you recognize this constellation? Through the icicles and past the mountains is Orion, one of the most identifiable star groupings on the sky and an icon familiar to humanity for over 30,000 years. Orion has looked pretty much the same during the past 50,000 years and should continue to look the same for many thousands of years into the future. Orion is quite prominent in the sky this time of year, a recurring sign of (modern) winter in Earth's northern hemisphere and summer in the south. Pictured, Orion was captured recently above the Austrian Alps in a composite of seven images taken by the same camera in the same location during the same night. Below and slightly to the right of Orion's three-star belt is the Orion Nebula, while the four bright stars surrounding the belt are, clockwise from the upper left, Betelgeuse, Bellatrix, Rigel, and Saiph.
22/01/2019
Science - Il était ...une éclipse : la Lune a pris des teintes bleutées
La Lune a pris des teintes bleutées.
21 janvier 2019, à Miami (Floride, Etats-Unis)
GASTON DE CARDENAS / AFP
21/01/2019
Science & Technologie - Stelvision : Une belle éclipse totale de Lune le 21 janvier 2019
Une éclipse de Lune a lieu lorsque le Soleil, la Terre et notre satellite sont parfaitement alignés : la Lune se trouve alors dans l’ombre de la Terre. On pourrait croire qu’il est possible de voir une éclipse chaque mois au moment de la pleine lune, mais notre satellite circule sur une orbite inclinée de cinq degrés par rapport à celle de la Terre. La plupart du temps, notre satellite passe donc un peu au-dessus ou un peu au-dessous de l’alignement Soleil-Terre et il n’y a pas d’éclipse. La dernière éclipse totale visible en Europe remonte à juillet 2018 et la prochaine aura lieu en mai 2022.
Une éclipse totale de Lune dure plusieurs heures et comporte différentes phases. Les passages dans la pénombre de la Terre, en début et fin de phénomène, sont peu spectaculaires car la Lune reçoit encore une partie des rayons solaires : elle reste donc grise. Beaucoup plus intéressante, la période ou la Lune se trouve partiellement ou totalement dans l’ombre de notre planète doit retenir toute votre attention : c’est à ce moment que la Lune s’assombrit progressivement et change de couleur !
Une belle éclipse totale de Lune le 21 janvier 2019
Science & Technology - Astronomy picture of the day - 2019 January 21 : InSight Lander Takes Selfie on Mars
Image Credit: NASA/JPL-Caltech
Explanation: This is what NASA's Insight lander looks like on Mars. With its solar panels, InSight is about the size of a small bus. Insight successfully landed on Mars in November with a main objective to detect seismic activity. The featured selfie is a compilation of several images taken of different parts of the InSight lander, by the lander's arm, at different times. SEIS, the orange-domed seismometer seen near the image center last month, has now been placed on the Martian surface. With this selfie, Mars InSight continues a long tradition of robotic spacecraft on Mars taking and returning images of themselves, including Viking, Sojourner, Pathfinder, Spirit, Opportunity, Phoenix, and Curiosity. Data taken by Mars Insight is expected to give humanity unprecedented data involving the interior of Mars, a region thought to harbor formation clues not only about Mars, but Earth.
20/01/2019
Science & Technology video - Astronomy picture of the day - 2019 January 20 : A Total Lunar Eclipse Video
Explanation: Tonight a bright full Moon will fade to red. Tonight's moon will be particularly bright because it is reaching its fully lit phase when it is relatively close to the Earth in its elliptical orbit. In fact, by some measures of size and brightness, tonight's full Moon is designated a supermoon, although perhaps the "super" is overstated because it will be only a few percent larger and brighter than the average full Moon. However, our Moon will fade to a dim redbecause it will also undergo a total lunar eclipse -- an episode when the Moon becomes completely engulfed in Earth's shadow. The faint red color results from blue sunlight being more strongly scattered away by the Earth's atmosphere. A January full moon, like the one visible tonight, is referred to as a Wolf Moon in some cultures. Tonight's supermoon total eclipse will last over an hour and be best visible from North and South America after sunset. Thefeatured time-lapse video shows the last total lunar eclipse -- which occurred in 2018 July. The next total lunar eclipse will occur only in 2021 May.
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