The Blood Moon Is Lit by Every Sunset on Earth

During a total lunar eclipse, not a single ray of direct sunlight reaches the Moon, yet it glows red instead of going black. This video follows that light as Earth's atmosphere bends it around the planet like a ring-shaped lens, strips out much of the blue, and pours every sunrise and sunset on Earth into the shadow at once. Then it shows how volcanic haze can dim that glow toward gray, from Agung and Pinatubo to an 1816 eclipse in which, by one account, the Moon vanished completely. 00:00 Red instead of black 00:39 Inside Earth's shadow 01:27 A ring-shaped lens of air 02:35 Why the light comes out red 03:41 Looking back from the Moon 04:44 Every sunrise and sunset at once 05:39 The Danjon scale: not every eclipse is red 06:45 Volcanoes turn the red down 07:51 Pinatubo and the gray Moon of 1992 09:10 How dim a blood moon really is 10:32 Tambora and the Moon that vanished 11:31 Lit by the edge of Earth Notes: Our own arithmetic, not measured figures: 'every 2.5 magnitudes is a factor of ten'; four magnitudes as 'roughly 40 times less light'; the 11.3-magnitude gap and 'about 33,000 times dimmer' for May 2022; the drop of at least 14.8 magnitudes and 'more than 800,000 times less light' for December 1992; and 'two of the five Danjon grades are gray, brown or barely there'. Illustrations: the view of Earth from the Moon at mid-eclipse and the ring of light around it are drawn from published descriptions, not from footage; the KAGUYA images of February 2009 show a penumbral eclipse, not a total one. 'Every sunrise and sunset at once' is our paraphrase of the idea, not a quotation. Contested or uncertain points: the Moon vanishing during an eclipse in the summer of 1816 is a second-hand account with no date; the link between Tambora and the Year Without a Summer is what many climatologists think, not a settled fact; the darkness of the May 2022 eclipse was linked by observers both to Hunga Tonga haze and to the Moon's path through the southern half of Earth's shadow, not to one single cause. More dust does not always mean a redder Moon: thick stratospheric haze makes it darker and grayer. The video names the bluish rim of the brightest eclipses but does not explain its cause. Sources Visual Appearance of Lunar Eclipses, Fred Espenak, EclipseWise (same text on NASA GSFC Eclipse Web Site), 2022-02-25 Volcanic Aerosols and Lunar Eclipses, R. A. Keen, Science (AAAS) vol. 222, p. 1011, 1983-12-02 Eclipses and the Moon, NASA Science, 2026-07-29 What Will 2014's and 2015's Lunar Eclipses Look Like?, Dr. Richard A. Keen, EclipseWise, 2014-09-21 KAGUYA HDTV images of the Earth at the time of a penumbral lunar eclipse (press release), JAXA, 2009-02-18 Danjon Scale of Lunar Eclipse Brightness, Fred Espenak, EclipseWise, 2022-05-18 Spring 2022 featured two stunning eclipses, Stephen James O'Meara, Astronomy magazine, 2022-12-01 Lowest Earth's atmosphere layers probed during a lunar eclipse, Kawauchi et al., Publications of the Astronomical Society of Japan (arXiv:1806.09085), 2018 Credits Illustrations and animations in the video: original, drawn in code for this channel. Fonts: Patrick Hand, Google Fonts (OFL-1.1) https://fonts.google.com/specimen/Pat... Patrick Hand SC, Google Fonts (OFL-1.1) https://fonts.google.com/specimen/Pat... Sriracha, Google Fonts (OFL-1.1) https://fonts.google.com/specimen/Sri.... Background music: generated for this channel.