Where in solar system are there solar eclipses like Earth's; i.e. eclipsing object subtends same arc as sun?

Question

On Earth, the sun seems about the same size as the moon, so a total solar eclipse leaves just the corona visible. Are there planets with a moon, a moon with a planet, or pairs of moons where such a close match in apparent size makes for near "perfect" eclipses?
This might be a good test for programming skills: you'd need a table of planets and satellites with diameters, distance to sun and each other, and orbital inclination (they might never actually eclipse the sun if a t wrong angle).

Answer 1

No. There isn't any quite like there are on Earth. The farther you are away from the sun, the smaller it looks. From Jupiter, each of its four large moons (Io, Europa, Ganymede, and Callisto) are all big enough to completely blot out the sun, but don't have the same apparent size as the sun, so you don't get the spectacular eclipses on Jupiter's "surface" (quotes because Jupiter has no surface, lawl) that you do here on Earth. Mercury and Venus have no moons. You can't have solar ecplises on the sun. Mars' moon Phobos does a somewhat good job of covering the sun in a Solar Eclipse like fashion, but Phobos isn't spherical, but rather irregular, like a rock. So although it has about the same apparent size as the sun does from the Martian surface, it doens't really cover it well. Deimos is smaller than Phobos, and is farther from the Martian surface. So Deimos can't ecplise. The Saturn system faces the same situation as the Jupiter system. All of it's spherical moons completely block out the sun. If you were to be at Saturn's "surface" (or rather, cloud tops), a moon would cover the sun completely, and there would be nothing but black. No spectacular corona effects. You wouldn't know the sun was even there. Guess what, same with Uranus and Neptune. The sun has a apparent size that is far to small to be effective eclipsed in the spectacular manor as here on Earth. Well that's all the planets. Pluto's Charon is too big, and the asteroid's all have irregular moons.

No programming skills needed, just need to have no "life" like I have, and know the solar system well. About moons in inclined orbits, remember that the Moon's orbit is inclined. The inclination however does not change as the Earth orbits the sun. So the line of the moon's orbit as viewed from the sun would appear to cross the Earth twice every Earth year. There is no inclination possible where it could not eclipse the host body.

High-inclination orbits for moons are unstable when you're closer to the star. The solar gravity causes the moon to go bye-bye when the angle between the star and the moon's orbit is 90 degrees. There's a constant sun-ward pull on the moon, and since the moon never heads in that direction, it looses it's orbital stability.

Cheers ^_^

Answer 2

Are there planets with a moon, a moon with a planet, or pairs of moons where such a close match in apparent size makes for near "perfect" eclipses?

With dozens of moons circling around Jupiter, all of them different-sized, that's a great question. I've never come across any mention of it, but I'll bet that's because ...

A) no one has ever asked that question before
or
B) no one has ever used computer programming to answer the question

Maybe I'm wrong about guessing that, but it would certainly make for an interesting research project!

Answer 3

The moon's apparent size is unique to the earth/moon system. All other planets' moons are much smaller and farther from their parent worlds than the moon. However, you could see the sun totally eclipsed if you were on Io for example and Europa (which is larger and closer to the sun than Io) moves across the sun. Since the sun is so tiny in the Jovian sky, you would get a total eclipse.
But it wouldn't be as spectacular as on earth - the sun is a large object and a total eclipse lets us see the photosphere and coronosphere (which you wouldn't see from another planet due to the distance).

Answer 4

That's easy.

THERE ARE NONE other than the Earth/Luna match.

Which leads some to suspect that the match in sizes is a little suspicious. An ancient message buy a superior intelligence?

Not that I buy into that. I suspect **** luck coincidence.