earth-moon fireman’s pole | juno images from jupiter

earthmoonpole

A five-year old asked on xkcd: If there were a kind of a fireman’s pole from the Moon down to the Earth, how long would it take to slide all the way from the Moon to the Earth?

First things first, it’s impossible to place a pole between the moon and the earth because of the two bodies’ constant movement. There is no stability whatsoever between the two end points of the pole. Then there are the scientific impossibilities–can’t slide because there’s no gravity between the two points, the relative rotation of the earth and the moon, the moon’s equivalent ground speed. Then there is the effect of sonic waves and the atmosphere. Plus the adventurer will gather so much speed coming towards earth that a huge giant mattress is needed to cushion the sudden stop.

Basically, too many variables.

But what if we froze the earth and the moon, and all of time except for our adventurer. It should be an easy calculation:

timedistancespeed

Assume we use the average lunar distance of 384,400km. The issue is, what do we use as speed? The earth’s gravitational acceleration is 9.8m/s, but that isn’t very helpful.

Anyway the answer.

Spoiler below.
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There is no answer.

Hmm. Too many unknowns.

So I don’t end a post with such an anticlimax, here’s a link to pictures of Jupiter that the spacecraft Juno has sent back. (All images below ©NASA.)

The familiar red spot, taken when Juno flew just 5,600 miles above it in July 2017:

junojupiter01

Then there’s this of Jupiter’s south pole, which is not visible from earth. It’s like the inside of a crystal:

junojupiter02

Cloud systems in the northern hemisphere:

junojupiter03

More at vox. Vox also reports that the mission is approved until July 2018 and if it doesn’t get extended, Juno will be abandoned and left to fall and get burnt up by Jupiter’s atmosphere.