冰岛上空的极光涡旋

冰岛上空的极光涡旋

ByNASA中文

2022年4月4日 A Vortex Aurora over Iceland Image Credit & Copyright: Christophe Suarez Explanation: No, the car was not in danger of being vacuumed into space by the big sky vortex. For one reason, the vortex was really an aurora, and since auroras are created by particles striking the Earth from space, they do not create a vacuum. This rapidly developing auroral display was caused by a Coronal Mass Ejection from the Sun that passed by the Earth closely enough to cause a ripple in Earth’s magnetosphere. The upper red parts of the aurora occur over 250 kilometers high with its red glow created by atmospheric atomic oxygen directly energized by incoming particles. The lower green parts of the aurora occur over 100 kilometers high with…

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…

冰岛上空的螺旋极光

冰岛上空的螺旋极光

ByNASA中文

2021年9月12日 A Spiral Aurora over Iceland Image Credit & Copyright: Davide Necchi Explanation: What’s happened to the sky? Aurora! Captured in 2015, this aurora was noted by Icelanders for its great brightness and quick development. The aurora resulted from a solar storm, with high energy particles bursting out from the Sun and through a crack in Earth’s protective magnetosphere a few days later. Although a spiral pattern can be discerned, creative humans might imagine the complex glow as an atmospheric apparition of any number of common icons. In the foreground of the featured image is the Ölfusá River while the lights illuminate a bridge in Selfoss City. Just beyond the low clouds is a nearly full Moon. The liveliness of the Sun — and likely…

冰岛上空的凤凰极光

冰岛上空的凤凰极光

ByNASA中文

2021年01月03日 A Phoenix Aurora over Iceland Image Credit & Copyright: Hallgrimur P. Helgason; Rollover Annotation: Judy Schmidt Explanation: All of the other aurora watchers had gone home. By 3:30 am in Iceland, on a quiet September night, much of that night’s auroras had died down. Suddenly, unexpectedly, a new burst of particles streamed down from space, lighting up the Earth’s atmosphere once again. This time, surprisingly, pareidoliacally, the night lit up with an amazing shape reminiscent of a giant phoenix. With camera equipment at the ready, two quick sky images were taken, followed immediately by a third of the land. The mountain in the background is Helgafell, while the small foreground river is called Kaldá, both located about 30 kilometers north of Iceland’s capital Reykjavík….

冰岛的星夜

冰岛的星夜

ByNASA中文

2020 January 5 A Starry Night of Iceland Image Credit: Stephane Vetter (Nuits sacrees) Explanation: On some nights, the sky is the best show in town. On this night, the sky was not only the best show in town, but a composite image of the sky won an international competition for landscape astrophotography. The featured winning image was taken in 2011 over Jökulsárlón, the largest glacial lake in Iceland. The photographer combined six exposures to capture not only two green auroral rings, but their reflections off the serene lake. Visible in the distant background sky is the band of our Milky Way Galaxy and the Andromeda galaxy. A powerful coronal mass ejection from the Sun caused auroras to be seen as far south as Wisconsin,…