APOD on Nostr: **Astronomy Picture of the Day** 11 September 2025 **The Umbra of Earth** Image ...
**Astronomy Picture of the Day**
11 September 2025
**The Umbra of Earth**
Image Credit & Copyright: Wang Letian
The dark, inner shadow of planet Earth is called the umbra. Shaped like a cone extending into space, it has a circular cross section most easily seen during a lunar eclipse. And on the night of September 7/8 the Full Moon passed near the center of Earth's umbral cone, entertaining eclipse watchers around much of our fair planet, including parts of Antarctica, Australia, Asia, Europe, and Africa. Recorded from Zhangjiakou City, China, this timelapse composite image uses successive pictures from the total lunar eclipse, progressing left to right, to reveal the curved cross-section of the umbral shadow sliding across the Moon. Sunlight scattered by the atmosphere into Earth's umbra causes the lunar surface to appear reddened during totality. But close to the umbra's edge, the limb of the eclipsed Moon shows a distinct blue hue. The blue eclipsed moonlight originates as rays of sunlight pass through layers high in the upper stratosphere, colored by ozone that scatters red light and transmits blue. In the total phase of this leisurely lunar eclipse, the Moon was completely within the Earth's umbra for about 83 minutes.
#APOD #Astrogeology #Exploration #Astrotheory #Cosmos
https://apod.nasa.gov/apod/ap250911.htmlPublished at
2025-09-11 04:09:10 GMTEvent JSON
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"content": "**Astronomy Picture of the Day**\n\n11 September 2025\n\n**The Umbra of Earth**\n\nhttps://apod.nasa.gov/apod/image/2509/UmbraEarth.jpg\n\nImage Credit \u0026 Copyright: Wang Letian\n\nThe dark, inner shadow of planet Earth is called the umbra. Shaped like a cone extending into space, it has a circular cross section most easily seen during a lunar eclipse. And on the night of September 7/8 the Full Moon passed near the center of Earth's umbral cone, entertaining eclipse watchers around much of our fair planet, including parts of Antarctica, Australia, Asia, Europe, and Africa. Recorded from Zhangjiakou City, China, this timelapse composite image uses successive pictures from the total lunar eclipse, progressing left to right, to reveal the curved cross-section of the umbral shadow sliding across the Moon. Sunlight scattered by the atmosphere into Earth's umbra causes the lunar surface to appear reddened during totality. But close to the umbra's edge, the limb of the eclipsed Moon shows a distinct blue hue. The blue eclipsed moonlight originates as rays of sunlight pass through layers high in the upper stratosphere, colored by ozone that scatters red light and transmits blue. In the total phase of this leisurely lunar eclipse, the Moon was completely within the Earth's umbra for about 83 minutes.\n\n#APOD #Astrogeology #Exploration #Astrotheory #Cosmos\n\nhttps://apod.nasa.gov/apod/ap250911.html\n",
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