Galileo's Camera

No, that was not a spelling mistake. It is actually part of the partial-shadow of the Earth. During a lunar eclipse, the Moon travels through the shadow of the Earth. If we manage to catch the entire movement of the Moon along with the shadow Earth casts on it, we can get something quite amazing, the actual shape of the Earth. Part of the shadow of Earth, as seen during the lunar eclipse on 10th Jan 2020

With the very first full moon of the year 2020, we were lucky to have a partial lunar eclipse. However, if you were a casual observer who sat up late to watch the eclipse, your response to this probably would have been "disappointing". Partial Lunar Eclipse at maximum - 10th January 2020 Canon 550D, 70-300mm at 300. F5.6 1/1000 ISO200 Penumbral lunar eclipses are usually a bit difficult observe as the contrast isn't that great. Unlike in solar eclipses where what we see is the silhouette of the Moon, in a lunar eclipse what we see is our own shadow. In fact, it is not the shadow itself, but the lighter shadow on the outside. Earth's umbra, penumbra and the Moon When the Moon is in the umbra, or the full shadow of the Earth, we get total lunar eclipses. When the Moon is in the penumbra, we get penumbral lunar eclipses. But these can be subdivided too; if only a part of the Moon is going through the umbra, then it becomes a partial lunar eclipse. Simi...

On 26th December 2019, we  witnessed an annular solar eclipse. Almost always, a solar eclipse doesn't come alone; it comes along with a lunar eclipse. And sure enough, nearly two weeks later, we have a penumbral lunar eclipse. Like the solar eclipse, this too is visible to Sri Lanka. In a penumbral lunar eclipse, the Moon goes through the penumbra, or the partial shadow of the Earth. Unlike the total lunar eclipse Sri Lankans were able to witness back on 28th June 2018, this will not be a "blood moon", it will simply become partially dark during the period. The lunar eclipse will start at 17:07 UTC (or 22:37 SL time on 10th) and will end at 21:12 UTC (or 02:42 SL time on 11th ). The greatest eclipse is at 19:21 UTC (or 00:51 SL time on 11th ). You can find more details about it at http://www.eclipsewise.com/lunar/LEprime/2001-2100/LE2020Jan10Nprime.html .  If you were curious about the author of that website, Fred Espenak is an American astrophysicist who has work...