Day: March 30, 2021

Red Sprite Lightning over the Andes

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What are those red filaments in the sky? They are a rarely seen form of lightning confirmed only about 30 years ago: red sprites. Recent research has shown that following a powerful positive cloud-to-ground lightning strike, red sprites may start as 100-meter balls of ionized air that shoot down from about 80-km high at 10 percent the speed of light. They are quickly followed by a group of upward streaking ionized balls. The featured image was taken earlier this year from Las Campanas observatory in Chile over the Andes Mountains in Argentina. Red sprites take only a fraction of a second to occur and are best seen when powerful thunderstorms are visible from the side. via NASA https://ift.tt/3ryEV0t

Wikipedia article of the day for March 30, 2021

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Wikipedia article of the day is Dresden Triptych. Check it out: https://ift.tt/3cwHPyw Summary: The Dresden Triptych is a very small hinged-triptych altarpiece signed and dated 1437 by the Early Netherlandish painter Jan van Eyck. It consists of five paintings: one central and four on two double-sided wings. It may have been intended as a portable altarpiece, and is his only extant non-portrait painting signed with his personal motto ALC IXH XAN (“I Do as I Can”). The outer wings show the Virgin Mary and the Archangel Gabriel in an Annunciation scene in grisaille. The inner panels are set in an ecclesiastical interior. In the central inner panel Mary holds the Christ Child; in the left-hand outer wing the Archangel Michael presents a kneeling donor; on the right Saint Catherine of Alexandria reads a prayer book (depicted). The triptych’s frames are the originals; richly decorated with Latin inscriptions, they indicate that the donor, whose identity is now lost, was highly educated. The coats of arms on the interior borders are associated with the Giustiniani of Genoa – an influential albergo active from 1362.