冰岛上空的螺旋极光

2023年1月11日

Spiral Aurora over Iceland
Image Credit & Copyright: Stefano Pellegrini

Explanation: The scene may look like a fantasy, but it’s really Iceland. The rock arch is named Gatklettur and located on the island’s northwest coast. Some of the larger rocks in the foreground span a meter across. The fog over the rocks is really moving waves averaged over long exposures. The featured image is a composite of several foreground and background shots taken with the same camera and from the same location on the same night last November. The location was picked for its picturesque foreground, but the timing was planned for its colorful background: aurora. The spiral aurora, far behind the arch, was one of the brightest seen in the astrophotographer’s life. The coiled pattern was fleeting, though, as auroral patterns waved and danced for hours during the cold night. Far in the background were the unchanging stars, with Earth’s rotation causing them to appear to slowly circle the sky’s northernmost point near Polaris.

Your Sky Surprise: What picture did APOD feature on your birthday? (post 1995)

Tomorrow’s picture: open space

冰岛上空的螺旋极光
图像提供与版权: Stefano Pellegrini

说明: 这片如幻想世界的场景，是出现在冰岛的真实景观。这座名为Gatklettur的石拱门，位在冰岛的西北海岸，而前景的一些较大岩块宽有1米。岩块上方的雾气，其实是涌动的海浪在长曝光下的积叠。这幅摄于去年11月的主题图像，是由同一部相机在同一地点拍摄的多张前景和背景照片组合而成。之所以选择在此地点拍摄，是因为它风景如画的前景，不过取像的时间之选择则是为了多彩多姿的背景极光。远在石拱门后方的螺旋极光，是这位天文摄影师此生所见的最明亮的极光之一。纵然极光在这个严寒的冬夜里摇曳舞动长达数小时，但图像中的螺旋极光却是转瞬即逝。而看似恒定在背景远后方的恒星，则在地球的自转下，看似缓缓绕着北极星附近的北天极盘旋。

你的天空惊喜: APOD在你生日那天发布了什么照片（1995年后）

明日的图片: open space