2025年2月24日
Light Pillar over Erupting Etna
Image Credit & Copyright: Davide Caliò
Explanation: Can a lava flow extend into the sky? No, but light from the lava flow can. One effect is something quite unusual — a volcanic light pillar. More typically, light pillars are caused by sunlight and so appear as a bright column that extends upward above a rising or setting Sun. Alternatively, other light pillars — some quite colorful — have been recorded above street and house lights. This light pillar, though, was illuminated by the red light emitted by the glowing magma of an erupting volcano. The volcano is Italy‘s Mount Etna, and the featured image was captured with a single shot during an early morning in mid-February. Freezing temperatures above the volcano’s lava flow created ice-crystals either in the air above the volcano or in condensed water vapor expelled by Mount Etna. These ice crystals — mostly flat toward the ground but fluttering — then reflected away light from the volcano’s caldera.
Tomorrow’s picture: stars between curtains
爆发中埃特纳火山上空的光柱
影像提供与版权: Davide Caliò
说明: 岩浆能流向天空吗？当然不能。不过，熔岩发出的光却可以，并偶而产生了不寻常的火山光柱。光柱通常是由太阳光所产生的，因此旭日或落日上方，偶而会出现明亮的垂直光柱。除此之外，街灯或房屋灯光等人造光源，有时也会产生色彩缤纷的光柱。然而，这张照片所记录的光柱，却是源自爆发中火山的熔岩所发出的红光。这座火山是意大利的埃特纳火山，而这张单曝光主题影像则是摄于2月中旬的某个清晨。拍照的当时，埃特纳火山岩浆流上空的低温环境，让空气中的水汽或火山排放的水蒸气凝结成冰晶。这些冰晶飘落时，扁平的晶面大致呈水平排列，得以共同反射来自火山口的红色光芒，产生了这道罕见的火山光柱。
明日的图片: stars between curtains
