Has any spacecraft ever captured a solar eclipse in which the earth, rather than the moon, precisely blocks the sun? I’m thinking that it would look similar to a normal total eclipse . . . except that if the resolution and exposure were just right, city lights might be visible.
Here’s a simulation. I’d be interested in seeing an actual image too.
There’s a (composite) picture of Saturn occluding the sun from images taken by the Cassini spacecraft, if that counts.
The Earth’s diameter is about 3.66 times that of the Moon’s so you’d have to be proportionately that much further away or about 1.4 million kilometers to get a “precise” eclipse like the Moon does for us. (This is approximate as the sun’s disk would look smaller as well as you moved out, but this would be reduced by only about 1% for a 1.4 million km move outward.) Now certainly we’ve had space craft that far away, though no manned craft.
The Earth would appear about the size that the Moon does to us (about 1% smaller). I don’t know if night city lights would be visible or not.
Here’s a video from the Solar Dynamics Observatory of the earth transiting the sun. Don’t blink or you’ll miss it, though.
I’d be surprised if it had happened, because the odds of it happening by chance are very low, and interplanetary probes have their trajectories determined by their destinations, rather than the opportunity of getting a snapshot like that along the way.
And in case it’s not clear to you, it would have to be an interplanetary probe. The earth is larger than the moon, so for it to fit exactly over the sun, the viewpoint would have to be proportionately farther from the earth than the moon is (but without doing even the quickest calculation, it would still be well inside the orbit of Mars).
But, by definition, you would be looking at the night side of the earth, so city lights would probably be visible if your camera had enough magnification.
No offence, but the next day’s apodwas cooler.
It almost certainly wouldn’t look just like a lunar eclipse, because of earth’s atmosphere. When you have a lunar eclipse, you can see the moon doesn’t have a sharp shadow* with well-defined arreas of light and dark, because light refra cts through the earth’s atmosphere, and the moon is colored coppery red. Of course, the moon istoo close for an eclipse, and so gets more of that refracted light than you’d expect, but even if you were far enough away, the earth would appear to be lit up around the edge by that light passing through the atmosphere (“seeing all Earth’s sunrises and sunsets at once”, is how Arthur C. Clarke once described the concept) So you’d see something more like an annnular eclipse.
Here, by the way, is something similar to what the OP asks for, but it’s a lunsar eclipse as seen from space. :
It seems pretty clear to me that a satellite at a Lagrange point, 60 degrees before or behind the earth, is going to get to see these on a regular basis (but not every month, of course. It’s still subject to the line of nodes, and all.)
*Of course, even with the ordinary eclipse made by the moon you don’t get a sharp shadow-- the sun subtends an angle as sen from the earth, so you get penumbra as well as umbra. If you look at photos of eclipses on the earth photographed from space you can see that it isn’t a hard-edged circular shadow:
In 1971 both Apollo 14 and Apollo 15 each lifted off from the Moon about 4 days before a full lunar eclipse. It’s a pity they couldn’t have stuck around and snapped a few photos … .