What's the slowest moving object in space, xkcd?


Hey crazy Randall!

The first question that triggered this little quest of mine, I actually asked just yesterday, when I saw an airplane very close by while going to lunch near an airport:

Why can't an airplane simply fly into space?

That was promptly answered by NASA: http://spaceplace.nasa.gov/review/dr-marc-technology/rockets.html

Then I went to some reading to get to the question in the title, namely:
- https://www.quora.com/Aerospace-and-Aeronautical-Engineering/Why-cant-an-aircraft-fly-conventionally-then-switch-to-rockets-to-get-into-space
- https://what-if.xkcd.com/58/ (obligatory read, for this topic)
- https://what-if.xkcd.com/24/ (obligatory read, for this topic)
- https://gmjunior.wordpress.com/tag/xkcd/
- http://space.stackexchange.com/questions/5531/why-arent-all-satellite-carrying-rockets-launched-from-airplanes

( The xkcd comics I found because I remembered about "what if" and googled for xkcd aircraft rocket. NASA and quora I found while asking google questions along my first one quoted there. )

I do realize now:

  1. An aircraft can't just fly away, for one, because it lifts from the ground depending on air and there's no air in space. Simple as that.

  2. Most things out of earth orbit are moving very very fast. Earth is at 30 km/s, ISS at 7, Moon at 3, which is still considerably faster than what's required to launch something into space, which would be 2 km/s as you said.

I take it all those speeds are relative to the Sun, which by its turn is 200 km/s relative to galaxy center. So I suppose a 0 km/s standing body on Earth is actually moving between 170 and 230 km/s relative to galaxy center and so, all object speeds are relative.

But, I wanted to draw a mental picture, in a way, of space objects in our galaxy. So objects relative to the Sun, as that's closer to any kind of Astronaut anyone living today will ever be. What's the slowest moving object there and how far from Earth, and from the other planets, does it need to be so it could be considered moving at 0km/s relative to the Sun? I mean, so it won't be dragged by any planet's or asteroid's gravity.

Do we know if there is any such slow object around here?

And, to address a bit more the first question in yet another "novel" way, of course we could build something to take objects into space that doesn't require flying or fuel: https://www.kickstarter.com/projects/michaellaine/space-elevator-science-climb-to-the-sky-a-tethered/description

At this point, I decided to google for xkcd slowest object space and came around yet another what-if: https://what-if.xkcd.com/86/ (obligatory read). And another cool funny one: https://what-if.xkcd.com/20/ (non obligatory).

There (on 86) you say:

As far as moving through the Solar System goes, Voyager 1 is one of the slowest manmade objects.[2] It's moving at an average speed of about 16 km/s, which is barely half of the Earth's orbital speed around the Sun.

[2] It's not the very slowest—that title might belong to the Galileo spacecraft. On September 6th, 1996 at 10:57 (UT), Galileo's speed relative to the Sun dropped to 276 meters per second (618 mph), making it possibly the slowest manmade object in Solar System history.

So, 0.276 km/s is quite slow compared to all the rest, but it's still far from 0.

Now, why do you say 16 km/s is "one of the slowest" (but by measures in this topic, I find it still quite fast) and then compare it to something over 50 times slower?!

And this triggered me into yet another new, but still relevant question:

  • What's the minimum speed an object need to be to eject the solar system?

Given the speed relative to Earth to eject it is 2 km/s.

Xkcd was dead staple horse wrong about passwords