流星与星系

流星与星系

ByNASA中文

2023年8月23日 The Meteor and the Galaxy Credit & Copyright: Jose Pedrero Explanation: It came from outer space. It — in this case a sand-sized bit of a comet nucleus — was likely ejected many years ago from Sun-orbiting Comet Swift-Tuttle, but then continued to orbit the Sun alone. When the Earth crossed through this orbit, the piece of comet debris impacted the atmosphere of our fair planet and was seen as a meteor. This meteor deteriorated, causing gases to be emitted that glowed in colors emitted by its component elements. The featured image was taken last week from Castilla La Mancha, Spain, during the peak night of the Perseids meteor shower. The picturesque meteor streak happened to appear in the only one of 50 frames…

流星解体时的元素发光

流星解体时的元素发光

ByNASA中文

2023年7月24日 Chemicals Glow as a Meteor Disintegrates Image Credit & Copyright: Michael Kleinburger Explanation: Meteors can be colorful. While the human eye usually cannot discern many colors, cameras often can. Pictured here is a fireball, a disintegrating meteor that was not only one of the brightest the photographer has ever seen, but colorful. The meteor was captured by chance in mid-July with a camera set up on Hochkar Mountain in Austria to photograph the central band of our Milky Way galaxy. The radiant grit, likely cast off by a comet or asteroid long ago, had the misfortune to enter Earth’s atmosphere. Colors in meteors usually originate from ionized chemical elements released as the meteor disintegrates, with blue-green typically originating from magnesium, calcium radiating violet, and…

阿尔卑斯山上空的流星与银河

阿尔卑斯山上空的流星与银河

ByNASA中文

2023年7月16日 Meteor and Milky Way over the Alps Image Credit & Copyright: Nicholas Roemmelt (Venture Photography) Explanation: Now this was a view with a thrill. From Mount Tschirgant in the Alps, you can see not only nearby towns and distant Tyrolean peaks, but also, weather permitting, stars, nebulas, and the band of the Milky Way Galaxy. What made the arduous climb worthwhile this night, though, was another peak — the peak of the 2018 Perseids Meteor Shower. As hoped, dispersing clouds allowed a picturesque sky-gazing session that included many faint meteors, all while a carefully positioned camera took a series of exposures. Suddenly, a thrilling meteor — bright and colorful — slashed down right next to the nearly vertical band of the Milky Way. As…

流星2023 CX1的亮闪

流星2023 CX1的亮闪

ByNASA中文

2023年2月17日 2023 CX1 Meteor Flash Image Credit & Copyright: Gijs de Reijke Explanation: While scanning the skies for near earth objects Hungarian astronomer Krisztián Sárneczky first imaged the meter-sized space rock now cataloged as 2023 CX1 on 12 February 2023 at 20:18:07 UTC. That was about 7 hours before it impacted planet Earth’s atmosphere. Its predicted trajectory created a rare opportunity for meteor observers and a last minute plan resulted in this spectacular image of the fireball, captured from the Netherlands as 2023 CX1 vaporized and broke up over northern France. Remarkably it was Sárneczky’s second discovery of an impacting asteroid, while 2023 CX1 is only the seventh asteroid to be detected before being successfully predicted to impact Earth. It has recently become the third…

地中海上空的流星和银河

地中海上空的流星和银河

ByNASA中文

2022年8月23日 Meteor & Milky Way over the Mediterranean Image Credit & Copyright: Julien Looten Explanation: Careful planning made this a nightscape to remember. First, the night itself was chosen to occur during the beginning of this year’s Perseid Meteor Shower. Next, the time of night was chosen to be before the bright Moon would rise and dominate the night sky’s brightness. The picturesque foreground was selected to be a rocky beach of the Mediterranean Sea in Le Dramont, France, with, at the time, île d’Or island situated near the ominously descending central band of our Milky Way Galaxy. Once everything was set and with the weather cooperating, all of the frames for this seemingly surreal nightscape were acquired within 15 minutes. What you can’t see…

突尼斯上空的流星雨

突尼斯上空的流星雨

ByNASA中文

2022年8月16日 A Meteor Wind over Tunisia Image Credit & Copyright: Makrem Larnaout Explanation: Does the Earth ever pass through a wind of meteors? Yes, and they are frequently visible as meteor showers. Almost all meteors are sand-sized debris that escaped from a Sun-orbiting comet or asteroid, debris that continues in an elongated orbit around the Sun. Circling the same Sun, our Earth can move through an orbiting debris stream, where it can appear, over time, as a meteor wind. The meteors that light up in Earth’s atmosphere, however, are usually destroyed. Their streaks, though, can all be traced back to a single point on the sky called the radiant. The featured image composite was taken over two days in late July near the ancient Berber…

英仙座流星雨与神奇望远镜

英仙座流星雨与神奇望远镜

ByNASA中文

2022年8月11日 Perseids and MAGIC Image Credit & Copyright: Urs Leutenegger Explanation: On August 11, 2021 a multi-mirror, 17 meter-diameter MAGIC telescope reflected this starry night sky from the Roque de los Muchachos European Northern Observatory on the Canary Island of La Palma. MAGIC stands for Major Atmospheric Gamma Imaging Cherenkov. The telescopes can see the brief flashes of optical light produced in particle air showers as high-energy gamma rays impact the Earth’s upper atmosphere. To the dark-adapted eye the mirror segments offer a tantalizing reflection of stars and nebulae along the plane of our Milky Way galaxy. But directly behind the segmented mirror telescope, low on the horizon, lies the constellation Perseus. And on that date the dramatic composite nightscape also captured meteors streaming from…

星系前方的流星

星系前方的流星

ByNASA中文

2022年8月7日 Meteor before Galaxy Image Credit & Copyright: Fritz Helmut Hemmerich Explanation: What’s that green streak in front of the Andromeda galaxy? A meteor. While photographing the Andromeda galaxy in 2016, near the peak of the Perseid Meteor Shower, a small pebble from deep space crossed right in front of our Milky Way Galaxy’s far-distant companion. The small meteor took only a fraction of a second to pass through this 10-degree field. The meteor flared several times while braking violently upon entering Earth’s atmosphere. The green color was created, at least in part, by the meteor’s gas glowing as it vaporized. Although the exposure was timed to catch a Perseid meteor, the orientation of the imaged streak seems a better match to a meteor from…

彗星与火流星

彗星与火流星

ByNASA中文

2021年12月20日 The Comet and the Fireball Image Credit & Copyright: Cory Poole Explanation: This picture was supposed to feature a comet. Specifically, a series of images of the brightest comet of 2021 were being captured: Comet Leonard. But the universe had other plans. Within a fraction of a second, a meteor so bright it could be called a fireball streaked through just below the comet. And the meteor’s flash was even more green than the comet’s coma. The cause of the meteor’s green was likely magnesium evaporating from the meteor’s pebble-sized core, while the cause of the comet’s green was likely diatomic carbon recently ejected from the comet’s city-sized nucleus. The images were taken 10 days ago over the Sacramento River and Mt. Lassen in…

冰岛上空的流星和极光

冰岛上空的流星和极光

ByNASA中文

2021年12月13日 Meteors and Auroras over Iceland Image Credit & Copyright: James Boardman-Woodend; Annotation: Judy Schmidt Explanation: What’s going on behind that mountain? Quite a bit. First of all, the mountain itself, named Kirkjufell, is quite old and located in western Iceland near the town of Grundarfjörður. In front of the steeply-sloped structure lies a fjord that had just begun to freeze when the above image was taken — in mid-December of 2012. Although quite faint to the unaided eye, the beautiful colors of background aurorae became quite apparent on the 25-second exposure. What makes this image of particular note, though, is that it also captures streaks from the Geminids meteor shower — meteors that might not have been evident were the aurora much brighter. Far…