Very simply put, even though the thumb is the same size, the relative distances between the eye, thumb and moon have changed. And now, Chris Hadfield's thumb does not appear to be bigger than the moon, when observed by Tom Hanks. And therefore, it can no longer block the moon from Tom Hanks' view.
Arguably, this is a matter of desired precision. If the shadow exists but is infinitessimally small, would you really consider that an eclipse? Where do you draw the line of what you consider an eclipse?
NASA explains this on their website:
There's a more intuitive way to express this. If a certain object (nearest planet) can block a light source (Sun), that means that from the point of view of the observer (on the furthest planet), the object must appear to be bigger than the light source. There's a quite well-known scene from Apollo 13 that showcases this:
Tom Hanks (as Jim Lovell) is blocking out the moon using his thumb. Even though the moon is much bigger than Tom Hanks' thumb (citation needed), the relative closeness of his thumb to his eye (compared to that of the moon) makes the thumb appear bigger than the moon.
So, we can reformulate your eclipse question: Is there any planet which appears to be bigger than the Sun, when observed from another planet?
The answer is no.
Edit: I've decided to make the below text easier to parse, by talking about the Earth and Venus. These are just examples, the same applies to any combination of planets, where Earth = furthest and Venus = nearest.
If you assume that the Sun is X times larger (in diameter!) than Venus, and the sun is Y times further from Earth than Venus is from Earth, then Venus will appear to be bigger than the sun (when standing on Earth) when X < Y.
In other words, when measuring the distance from Earth, the sun needs to be further away than Venus by a larger factor than the sun is bigger than the Venus.
As a simple example, if the sun were exactly 5 times bigger than Venus, it would have to be >5 times as far from Earth as Venus is, for it to appear to be smaller than Venus.
If you look up the numbers for planet diameters and orbital radii, you'll notice that this doesn't happen in our solar system. Not even close. This is because the sun is simply too big relative to any ratio of two planetary orbits.
Arguably, this is a matter of desired precision. If the shadow exists but is infinitessimally small, would you really consider that an eclipse? Where do you draw the line of what you consider an eclipse?
NASA explains this on their website:
NASA explains this on their website:
There's a more intuitive way to express this. If a certain object (nearest planet) can block a light source (Sun), that means that from the point of view of the observer (on the furthest planet), the object must appear to be bigger than the light source. There's a quite well-known scene from Apollo 13 that showcases this:
Tom Hanks (as Jim Lovell) is blocking out the moon using his thumb. Even though the moon is much bigger than Tom Hanks' thumb (citation needed), the relative closeness of his thumb to his eye (compared to that of the moon) makes the thumb appear bigger than the moon.
So, we can reformulate your eclipse question: Is there any planet which appears to be bigger than the Sun, when observed from another planet?
The answer is no.
Edit: I've decided to make the below text easier to parse, by talking about the Earth and Venus. These are just examples, the same applies to any combination of planets, where Earth = furthest and Venus = nearest.
If you assume that the Sun is X times larger (in diameter!) than Venus, and the sun is Y times further from Earth than Venus is from Earth, then Venus will appear to be bigger than the sun (when standing on Earth) when X < Y.
In other words, when measuring the distance from Earth, the sun needs to be further away than Venus by a larger factor than the sun is bigger than the Venus.
As a simple example, if the sun were exactly 5 times bigger than Venus, it would have to be >5 times as far from Earth as Venus is, for it to appear to be smaller than Venus.
If you look up the numbers for planet diameters and orbital radii, you'll notice that this doesn't happen in our solar system. Not even close. This is because the sun is simply too big relative to any ratio of two planetary orbits.