Title text:
I'm excited for Dragonfly, because on the list of places in the solar system that I desperately want more pictures from, 'Titan's surface' is right up there at the top with 'Jupiter's atmosphere.'
Transcript:
Transcript will show once it’s been added to explainxkcd.com
Source: https://xkcd.com/3322/
Sure. 25% --> 37% ... as long as you (for some arbitrary reason) only consider 8 "places" in the solar system.
7 of those are planets, but Titan is a moon. If we're going to include moons, then there's going to be a whole lot more than 8 "places" in the solar system, so the percentage of places where helicopters can work is going to be greatly reduced. If we get really pedantic and consider any orbiting body in the solar system to be a "place", then there will be hundreds, thousands of them where helicopters can't possibly work, once you start tallying up asteroids and comets.
Also, why does the list include 7 planets, not 8? What? Are you not interested in trying to make a helicopter work on Mercury? That's quitter talk!
Places where helicopters can work is places with sufficient atmosphere, which is why the list is what it is
Ah, but what if you brought a large balloon, inflated it, and flew a helicopter inside the balloon?
Jupiter is already on the list…
Blowing my mind that Gas Giants are just big ole balloons
It’s an inside out balloon! Gravity holds the atmosphere in, not a cloth sheet
And I have a hard time believing that there isn't some solid or liquid (or maybe some other exotic state of matter, due to the heat and pressure) inner core way down in there, even if it's relatively tiny compared to the size of the planet.
Even if it was entirely made of gas when it formed, surely some materials would have fallen in over the eons that could stay solid/liquid at the pressure/temperature of a gas giant's core?
Filling the balloon woth helium should keep it from hitting the ground and popping
The list is only of "places where helicopter would work". The checkmarks are the ones we've sent helicopters to.
Why is Uranus not checked then?
I think it's saying those are the eight places a helicopter could work, and we are checking them off as we accomplish them.
Helicopters require atmosphere (obviously), so this is a list of the eight bodies in the solar system with atmosphere sufficient for heavier-than-air flight.
Mercury basically doesn't have an atmosphere for instance, which is probably why it's not on the list.
If you do a little homework, these are the worlds with atmospheres, as required for helicopter functions.