Recent comments in /f/space

dreamchains t1_jdoav8e wrote

Not quite, it depends on the orientation of the planets (pole to pole/side to side) and the position of the moon. But that makes it even more interesting to me how close those numbers happen to be.

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aurumae t1_jdoahwd wrote

“Half the distance to the moon” makes it seem like this is a very close approach, and in relative terms it is.

But the distance between Earth and the moon is still mind-bogglingly huge. So big, that you could fit all the other planets in the solar system end-to-end between Earth and the moon and still have space to spare

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Nowbob t1_jdo9nhq wrote

>a circle with the diameter of the lunar orbit is very close to 1/64th the radius of earth

???

What am I missing here? The lunar orbit is MUUUUUCH larger than the radius of the earth isn't it?

Wouldn't the lunar orbit being 1/64 the radius of the earth mean that the moon is whizzing past just barely overhead?

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reedef t1_jdo52pd wrote

You also have to account for the fact that the earth itself attracts asteroids even if they're not heading 100% towards the earth, though I'm not sure how large of an effect that is at interplanetary speeds

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za419 t1_jdo52fp wrote

We'd have to do some orbital mechanics on this one. Most things in the solar system are roughly coplanar on the ecliptic, so the real shape is probably a section of the sphere a few degrees wide.

Or we could probably just guess and multiply the space available by a substantial number, because even that section is going to be pretty tall compared to the Earth. Space is big.

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You_Yew_Ewe t1_jdnze2x wrote

The magnitude of earth's gravity varies [pretty haphazardly across the globe](https://www.popsci.com/science/article/2010-06/esa-satellite-maps-earths-gravity-3-d/). It's not closely correlated with the equator.

Maybe you mean because of the sum of gravity and centrifugal force makes means the mass has less weight?

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