猎鹰重型火箭之返回喷燃

猎鹰重型火箭之返回喷燃

BySamuel Chan

2024年1月20日 Falcon Heavy Boostback Burn Image Credit & Copyright: Dennis Huff Explanation: 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. Their next…

2小时30分钟期间的木星

2小时30分钟期间的木星

BySamuel Chan

2024年1月19日 Jupiter over 2 Hours and 30 Minutes Image Credit & License: Aurélien Genin Explanation: Jupiter, our Solar System’s ruling gas giant, is also the fastest spinning planet, rotating once in less than 10 hours. The gas giant doesn’t rotate like a solid body though. A day on Jupiter is about 9 hours and 56 minutes long at the poles, decreasing to 9 hours and 50 minutes near the equator. The giant planet’s fast rotation creates strong jet streams, separating its clouds into planet girdling bands of dark belts and bright zones. You can easily follow Jupiter’s rapid rotation in this sharp sequence of images from the night of January 15, all taken with a camera and small telescope outside of Paris, France. Located just…

在平流层所见的北极光

在平流层所见的北极光

BySamuel Chan

2024年1月18日 Northern Lights from the Stratosphere Image Credit & Copyright: Ralf Rohner Explanation: Northern lights shine in this night skyview from planet Earth’s stratosphere, captured on January 15. The single, 5 second exposure was made with a hand-held camera on board an aircraft above Winnipeg, Canada. During the exposure, terrestrial lights below leave colorful trails along the direction of motion of the speeding aircraft. Above the more distant horizon, energetic particles accelerated along Earth’s magnetic field at the planet’s polar regions excite atomic oxygen to create the shimmering display of Aurora Borealis. The aurora’s characteristic greenish hue is generated at altitudes of 100-300 kilometers and red at even higher altitudes and lower atmospheric densities. The luminous glow of faint stars along the plane of our…

美国号与宁静海

美国号与宁静海

BySamuel Chan

2024年1月17日 America and the Sea of Serenity Image Credit & Copyright: Gene Cernan, Apollo 17, NASA; Anaglyph by Patrick Vantuyne Explanation: Get out your red/blue glasses and check out this stereo view of another world. The scene was recorded by Apollo 17 mission commander Eugene Cernan on December 11, 1972, one orbit before descending to land on the Moon. The stereo anaglyph was assembled from two photographs (AS17-147-22465, AS17-147-22466) captured from his vantage point on board the Lunar Module Challenger as he and Dr. Harrison Schmitt flew over Apollo 17’s landing site in the Taurus-Littrow Valley. The broad, sunlit face of the mountain dubbed South Massif rises near the center of the frame, above the dark floor of Taurus-Littrow to its left. Piloted by Ron…

肉眼几乎可见的猎户座

肉眼几乎可见的猎户座

BySamuel Chan

2024年1月16日 The Orion You Can Almost See Image Credit & Copyright: Michele Guzzini Explanation: Do you recognize this constellation? Although it is one of the most recognizable star groupings on the sky, this is a more full Orion than you can see — an Orion only revealed with long exposure digital camera imaging and post– processing. Here the cool red giant Betelgeuse takes on a strong orange tint as the brightest star on the upper left. Orion‘s hot blue stars are numerous, with supergiant Rigel balancing Betelgeuse on the lower right, and Bellatrix at the upper right. Lined up in Orion’s belt are three stars all about 1,500 light-years away, born from the constellation’s well-studied interstellar clouds. Just below Orion’s belt is a bright but…

韦伯影像: 星团IC 348

韦伯影像: 星团IC 348

BySamuel Chan

2024年1月15日 Star Cluster IC 348 from Webb Image Credit: NASA, ESA, CSA, STScI, and K. Luhman (Penn State U.) and C. Alves de Oliveira (ESA) Explanation: Sometimes, it’s the stars that are the hardest to see that are the most interesting. IC 348 is a young star cluster that illuminates surrounding filamentary dust. The stringy and winding dust appears pink in this recently released infrared image from the Webb Space Telescope. In visible light, this dust reflects mostly blue light, giving the surrounding material the familiar blue hue of a reflection nebula. Besides bright stars, several cool objects have been located in IC 348, visible because they glow brighter in infrared light. These objects are hypothesized to be low mass brown dwarfs. Evidence for this…

冰岛上空的龙形极光

冰岛上空的龙形极光

BySamuel Chan

2024年1月14日 Dragon Aurora over Iceland Image Credit & Copyright: Jingyi Zhang & Wang Zheng Explanation: Have you ever seen a dragon in the sky? Although real flying dragons don’t exist, a huge dragon-shaped aurora developed in the sky over Iceland in 2019. The aurora was caused by a hole in the Sun’s corona that expelled charged particles into a solar wind that followed a changing interplanetary magnetic field to Earth’s magnetosphere. As some of those particles then struck Earth’s atmosphere, they excited atoms which subsequently emitted light: aurora. This iconic display was so enthralling that the photographer’s mother ran out to see it and was captured in the foreground. Our active Sun continues to show an unusually high number of prominences, filaments, sunspots, and large…

日晕与太阳

日晕与太阳

BySamuel Chan

2024年1月13日 Circling the Sun Image Credit & Copyright: Radoslav Zboran Explanation: Earth’s orbit around the Sun is not a circle, it’s an ellipse. The point along its elliptical orbit where our fair planet is closest to the Sun is called perihelion. This year, perihelion was on January 2 at 01:00 UTC, with the Earth about 3 million miles closer to the Sun than it was at aphelion (last July 6), the farthest point in its elliptical orbit. Of course, distance from the Sun doesn’t determine the seasons, and it doesn’t the determine size of Sun halos. Easier to see with the Sun hidden behind a tall tree trunk, this beautiful ice halo forms a 22 degree-wide circle around the Sun, recorded while strolling through the…

早安！月亮

早安！月亮

BySamuel Chan

2024年1月12日 Good Morning Moon Image Credit & Copyright: Michael Luy, Trier Observatory, TWAN Explanation: Yesterday, the Moon was New. But on January 9, early morning risers around planet Earth were treated to the sight of an old Moon, low in the east as the sky grew bright before dawn. Above the city of Saarburg in Rhineland-Palatinate, western Germany, this simple snapshot found the waning Moon’s sunlit crescent just before sunrise. But also never wandering far from the Sun in Earth’s sky, inner planets Venus and Mercury shared the cold morning skyview. In the foreground are the historic city’s tower and castle with ruins from the 10th century. Tomorrow’s picture: circle around the Sun 早安！月亮 影像提供与版权: Michael Luy, Trier Observatory, TWAN 说明: 昨天适逢新月（农历初一）。然而在1月9日，世界各地早起的人们所见到的，却是渐亮天空中低悬在东方的残月。例如于这幅记录德国西部莱茵兰-华尔茨州萨尔堡市天空的影像里，即可见到日出前的一抺蛾眉月。除此之外，还可见到在地球天空中，总是徘徊在太阳附近的内行星─金星与水星，共同分享了这片严寒的清晨美景。这幅影像的前景为这座历史名城的塔楼和城堡，以及来自十世纪的废墟。 明日的图片: circle around…

北半球的四分仪流星雨

北半球的四分仪流星雨

BySamuel Chan

2024年1月11日 Quadrantids of the North Image Credit & Copyright: 염범석 Yeom Beom-seok Explanation: Named for a forgotten constellation, the Quadrantid Meteor Shower puts on an annual show for planet Earth’s northern hemisphere skygazers. The shower’s radiant on the sky lies within the old, astronomically obsolete constellation Quadrans Muralis. That location is not far from the Big Dipper asterism, known to some as the Plough, at the boundaries of the modern constellations Bootes and Draco. In fact the Big Dipper “handle” stars are near the upper right corner in this frame, with the meteor shower radiant just below. North star Polaris is toward the top left. Pointing back toward the radiant, Quadrantid meteors streak through the night in this skyscape from Jangsu, South Korea. The composite…