2022 November 14
Explanation: What powers are being wielded in the Wizard Nebula? Gravitation strong enough to form stars, and stellar winds and radiations powerful enough to create and dissolve towers of gas. Located only 8,000 light years away, the Wizard nebula, featured here, surrounds developing open star cluster NGC 7380. Visually, the interplay of stars, gas, and dust has created a shape that appears to some like a fictional medieval sorcerer. The active star forming region spans 100 about light years, making it appear larger than the angular extent of the Moon. The Wizard Nebula can be located with a small telescope toward the constellation of the King of Aethiopia (Cepheus). Although the nebula may last only a few million years, some of the stars being formed may outlive our Sun.
2022 November 13
Explanation: A flying saucer from outer space crash-landed in the Utah desert after being tracked by radar and chased by helicopters. The year was 2004, and no space aliens were involved. The saucer, pictured here, was the Genesis sample return capsule, part of a human-made robot Genesis spaceship launched in 2001 by NASA itself to study the Sun. The unexpectedly hard landing at over 300 kilometers per hour occurred because the parachutes did not open as planned. The Genesis mission had been orbiting the Sun collecting solar wind particles that are usually deflected away by Earth's magnetic field. Despite the crash landing, many return samples remained in good enough condition to analyze. So far, Genesis-related discoveries include new details about the composition of the Sun and how the abundance of some types of elements differ across the Solar System. These results have provided intriguing clues into details of how the Sun and planets formed billions of years ago.
2022 November 12
Explanation: A darker Moon sets over Manhattan in this night skyscape. The 16 frame composite was assembled from consecutive exposures recorded during the November 8 total lunar eclipse. In the timelapse sequence stars leave short trails above the urban skyline, while the Moon remains immersed in Earth's shadow. But the International Space Station was just emerging from the shadow into the sunlit portion of its low Earth orbit. As seen from New York City, the visible streak of this ISS flyover starts near a star in Taurus and tracks right to left, through the belt of Orion and over Sirius, alpha star of Canis Major. Gaps along the bright trail of the fast moving orbital outpost (and an aircraft flying closer to the horizon) mark the time between individual exposures in the sequence. The trail of bright planet Mars is at the top of the frame. Pleiades star cluster trails are high over the eclipsed Moon and Empire State Building.
2022 November 11
Explanation: On November 8 the Full Moon turned blood red as it slid through Earth's shadow in a beautiful total lunar eclipse. During totality it also passed in front of, or occulted, outer planet Uranus for eclipse viewers located in parts of northern America and Asia. For a close-up and wider view these two images were taken just before the occultation began, captured with different telescopes and cameras from the same roof top in Shanghai, China. Normally very faint compared to a Full Moon, the tiny, pale, greenish disk of the distant ice giant is just to the left of the Moon's edge and about to disappear behind the darkened, red lunar limb. Though only visible from certain locations across planet Earth, lunar occultations of planets are fairly common. But for this rare "lunar eclipse occultation" to take place, at the time of the total eclipse the outer planet had to be both at opposition and very near the ecliptic plane to fall in line with Sun, Earth, and Moon.
022 November 10
Explanation: The beginning, middle, and end of a journey through planet Earth's colorful umbral shadow is captured in this timelapse composite image of a total lunar eclipse. Taken on November 8 from Kitt Peak National Observatory this eclipse's 1 hour and 25 minute long total phase starts on the right and finishes on the left. Reddened sunlight, scattered into the central shadow by Earth's dusty atmosphere produces the dramatic dark red hues reflected by the lunar disk. For this eclipse, additional reddening is likely due to scattering from ash lingering in the atmosphere after a large volcanic eruption in the southern Pacific earlier this year. Seen at the right and left, the Earth's shadow is still lighter along its edge though. That faint bluish fringe along the lunar limb is colored by sunlight filtered through Earth's stratospheric ozone layer.
2022 November 9
Explanation: Why does the nebula around the star WR-18 shine brighter on one side? Also known as NGC 3199, this active star and its surrounding nebula lie about 12,000 light-years away toward the nautical southern constellation of Carina. The featured deep image has been highly processed to bring out filamentary details of the glowing gas in the bubble-shaped nebula. The nebula is about 75 light-years across. Near the nebula's center is a Wolf-Rayet star, WR-18, which is a massive, hot, short-lived star that generates an intense and complex stellar wind. In fact, Wolf-Rayet stars are known to create nebulas with interesting shapes as their powerful winds sweep up surrounding interstellar material. In this case, the bright right edge was initially thought to indicate that a bow shock was being produced as the star plowed through a uniform medium, like a boat through water. Recent measurements and analyses, however, have shown the star is not moving quickly toward the bright edge. A more likely explanation has emerged that the material surrounding the star is not uniform, but clumped and denser near the bright edge.
2022 November 8
Explanation: How many galaxies are interacting here? This grouping of galaxies is called the Wild Triplet, not only for the discoverer, but for the number of bright galaxies that appear. It had been assumed that all three galaxies, collectively cataloged as Arp 248, are interacting, but more recent investigations reveal that only the brightest two galaxies are sparring gravitationally: the big galaxies at the top and bottom. The spiral galaxy in the middle of the featured image by the Hubble Space Telescope is actually far in the distance, as is the galaxy just below it and all of the other numerous galaxies in the field. A striking result of these giants jousting is a tremendous bridge of stars, gas, and dust that stretches between them -- a bridge almost 200,000 light-years long. Light we see today from Wild's Triplet left about 200 million years ago, when dinosaurs roamed the Earth. In perhaps a billion years or so, the two interacting galaxies will merge to form a single large spiral galaxy.
Sur cette image, on peut apercevoir les tailles des différentes planètes du Système solaire ainsi que du Soleil . Ou comment se sentir tout...
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