蓝绿色仙境上空的银河

蓝绿色仙境上空的银河

2023年5月29日 Milky Way over a Turquoise Wonderland Image Credit & Copyright: Petr Horálek / Institute of Physics in Opava, Sovena Jani Explanation: What glows there? The answer depends: sea or sky? In the sea, the unusual blue glow is bioluminescence. Specifically, the glimmer arises from Noctiluca scintillans, single-celled plankton stimulated by the lapping waves. The plankton use their glow to startle and illuminate predators. This mid-February display on an island in the Maldives was so intense that the astrophotographer described it as a turquoise wonderland. In the sky, by contrast, are the more familiar glows of stars and nebulas. The white band rising from the artificially-illuminated green plants is created by billions of stars in the central disk of our Milky Way Galaxy. Also visible…

马尔代夫夜空的珍宝

马尔代夫夜空的珍宝

2022年3月28日 Gems of a Maldivean Night Image Credit & Copyright: Petr Horálek (ESO Photo Ambassador, Inst. of Physics in Opava) Explanation: The southernmost part of the Milky Way contains not only the stars of the Southern Cross, but the closest star system to our Sun — Alpha Centauri. The Southern Cross itself is topped by the bright, yellowish star Gamma Crucis. A line from Gamma Crucis through the blue star at the bottom of the cross, Acrux, points toward the south celestial pole, located just above the small island in the featured picture — taken in early March. That island is Madivaru of the Maldives in the Indian Ocean. Against faint Milky Way starlight, the dark Coal Sack Nebula lies just left of the cross,…