# Has the Earth's red atmosphere rim ever been photographed?

In the Wikipedia article on Lunar eclipse there's given an image of how the Earth would look from the eclipsed Moon:

This is obviously a schematic drawing. So I wonder, has the Earth ever been actually photographed from such a position where both the Earth and the Sun have comparable angular sizes, and the Earth completely obscures the Sun, making the red glow of atmosphere easily visible?

By comparable angular sizes I mean like e.g. 4:1 ratio as seen from the Moon, unlike the ratio of ~170:1 as seen from the LEO.

• It’s worth noting that unlike a normal solar eclipse where the moon and sun have almost the same apparent size, a solar eclipse as viewed from the moon would have the Earth appear much larger than the sun. You would have to be much more distant than the moon to achieve a comparable apparent size – Jack Aug 13 '18 at 12:15
• @Jack how much is much? According to this answer, angular size of the Earth as seen from the Moon is about $1.9^\circ$, while the Sun should still be about $0.5^\circ$, which is only 4 times ratio, which I still think as comparable. – Ruslan Aug 13 '18 at 12:18
• @Jack reworded to make it more explicit. – Ruslan Aug 13 '18 at 12:39
• Related but not a duplicate Have there been any photos taken of a total Earth-Sun eclipse from the Moon, or its vicinity? – uhoh Aug 14 '18 at 3:55

As discussed here, very few satellites have ever orbited at a higher altitude than the moon, making images from lunar orbiters our highest imagers of eclipses from orbit. In fact, in order to get a 1:1 ratio of the apparent sizes of the Sun and the Earth you would have to be at ~4x the altitude of the moon - right near the edge of Earth's Hill Sphere. This makes stable Earth orbits essentially impossible so any images taken from here would be from escaping/returning spacecraft.

Here is a beautiful sequence taken by JAXA's Kaguya (SELENE) lunar orbiter around the time of the Febraury 2009 lunar eclipse1. Note the lower edge of the Earth is hidden behind the surface of the moon.

If you look very closely, you'll notice there is a difference in colour around the ring of Earth's atmosphere. This is down to the varying angles refracting different wavelengths. The actual footage demonstrates the difficulties in capturing images of the sun from orbit - a lovely delicate ring of light circling the Earth followed by a blinding wash-out as soon as the Sun comes into view.

The first ever images taken from the Moon of the Earth eclipsing the Sun were all the way back in 1967! Surveyor 3 took this short sequence of images2:

Another famous image was taken on Apollo 12 en-route to the moon where some refraction effects through the atmosphere can be seen3. This is from significantly closer to the Earth.

One difficulty with taking images of eclipses from the moon is the lack of sunlight itself. Lunar orbiters are often designed to use solar power in the sunlit portions of their orbits and battery power while in shadow. The potentially extended period of darkness during an eclipse can drain power reserves and is compounded by the associated increase in heating requirements. For this reason, non-essential systems are usually powered down - read about how this was handled by NASA's LADEE and LRO.

1Image credit: JAXA/NHK

2Image credit: NASA

3Image credit: NASA/JSC

• Although beautiful, the bad thing about these two examples is that the essential redness of the atmosphere ring is blown out (in case of Apollo) or seems to be lacking (in case of Kaguya). In both cases the ring seems to be mostly blue, not red, and only in some places does it appear red. But well, maybe we simply don't have better photos. – Ruslan Aug 13 '18 at 14:06
• Good old Goresat is further out than the moon but sadly always between the Sun and the Earth. We need an anti-Goresat at the other Lagrange point so it's always eclipsed. Solar power might be an issue though :) – Organic Marble Aug 13 '18 at 14:28
• @Ruslan Kaguya's HDTV camera records in the visible range so it's a good representation of what the eclipse looks like from the Moon. However, if the Sun were more directly behind the Earth - rather than near the edge as shown here - there may be more red colouration. I'm unsure if Kaguya has taken any footage like that though. – Jack Aug 13 '18 at 14:35