# Terran eclipse?

Solar and lunar eclipses are pretty straightforward. But what about eclipses when you are standing on the Moon? I have been trying to Google the info, but there's some gaming clan that has taken the name "terran eclipse" so it's hard to find the real stuff.

I was able to find this article on lunar eclipse from the Moon (the Earth eclipsing the sun). But what about the other way - a solar eclipse observed from the Moon? What would Earth look like? Would anything special be happening on the Moon?

• A "terran eclipse" is just a lunar eclipse, observed from the Moon. – SE - stop firing the good guys Oct 7 '16 at 15:07
• Trivia: a total lunar eclipse occurred shortly after Apollo 15. (The astronauts had already left.) The mission report states the equipment left there recorded a temperature swing of 283 degrees F (140 degrees C) So expect it to get cold... – Andy Oct 7 '16 at 15:12
• Not an answer, but a helpful piece of Google advice. You can tell Google to omit results with certain words by adding a '-' in front of them. If you search "terran eclipse -game -community", it gets rid of most of that stuff and the results contain more eclipse from the moon results. It doesn't get rid of all of it, but with a few more terms ignored you can boil it down to just what you're looking for. – Cody Oct 7 '16 at 15:51

## 2 Answers

As Wayfaring Stranger's answer says, during a lunar eclipse seen from Earth, an observer on the Moon would see a solar eclipse. Earth is about 4 times the apparent diameter of the Sun. You can see a photo of such an eclipse, taken by Japan's Kaguya spacecraft in lunar orbit, here.

During a solar eclipse seen from Earth, an observer on the Moon would see the Moon's shadow on the surface of Earth. I don't know of any photos of such a shadow as seen from the Moon, but here's a photo of a solar eclipse seen from the Mir space station in 1999.

https://apod.nasa.gov/apod/ap110102.html

• @Pavel Just to note, as seen in the bottom photo, the moon's shadow on Earth (during solar eclipse) is much smaller than the Earth's shadow upon the moon during lunar eclipses. In fact "terran eclipse" might be a misnomer -- the Earth can never be totally "shadowed" by the moon. – Jeff Y Oct 13 '16 at 13:54
• +1 also asked and answered in Space SE: Have there been any photos taken of a total Earth-Sun eclipse from the Moon, or its vicinity? – uhoh Feb 4 '19 at 4:14

A lunar eclipse on earth is a solar eclipse on the moon. The earth takes up 2° of sky from the lunar surface (vs 0.5°), so you'd see less corona in your space suit. The moon's speed through earth's shadow is only about 1 km per second, so you'd have up to 107 minutes of totality. What with earth's atmosphere, I doubt you'd see much in the way of Baily's beads, but there'd likely be a spectacular round the world sunset glow to make up for that.