So how do we get to Venus? Is it like throwing a hammer at the Earth from the ISS? Does the probe have to go around the Sun a zillion times before it gets there?
Oh, never mind—now that I picture it in my head, it’s not a zillion times. :smack: It’s more like halfway around once, and the probes takes maybe six months to get there, right? But if you chucked a hammer out the window of the ISS it would orbit the Earth quite a few times before it hit the ground, right? (This is assuming a magical hammer that doesn’t burn up/melt.)
I suggest dropping it into the Marianas Trench instead. It will eventually be subducted into the Earth’s crust.
That’s not a bad idea.
But similarly, Mercury MESSENGER, which is due to arrive in orbit this year, was launched over six years ago, having had to make numerous swingbys to slow it down.
You’re right, it’s not a bad idea - it’s a terrible idea.
On paper, I mean. Of course it’s not feasible in real life, but it sounds good.
No, it doesn’t even sound good.
How long do you think it would take to subduct the waste into the mantle (hint - think geological timescale)? What happens to it in the meantime?
For a while, yes. But as the Sun is pulling the trash in, it’s causing the trash to speed up, and at some point, it’s going to be going so fast that it just zooms right past the Sun and gets flung back up to its starting height, lather, rinse, and repeat (which, really, is how all orbits work). To prevent this from happening, you need to actually hit the surface of the Sun some time before that lower turnaround point, which means that the lower turnaround point needs to be really low.
We wait.
As long as it has any orbital momentum (speed in a direction lateral to the Sun) it will just remain in an elliptical orbit per Kepler’s laws of planetary motion (warning: cool Flash app that demonstrates Kepler’s laws with variation).
Stranger
Great link, Stranger!
Will be showing it to the grandsons next weekend.
Thanks.
No, it pollutes the ocean.
Why not just stick it in your backyard, it’s easier.
No. If you chucked a hammer out the window of the ISS, that hammer will be in orbit around the Earth, just at a very slightly different orbit than the ISS.
If you’re sitting on your space station, and decide to drop your trash overboard, what happens? The trash doesn’t drop straight down to Earth. The trash was orbiting with you. And what is an orbit? An orbit means you’re falling towards the object you’re orbiting, but you’ve got enough of a sideways vector to keep missing it.
If you get the mechanics right, you can fall in a perfect circle around the body. But if you slow down a little, you don’t slowly spiral in. Rather, you go into an elliptical orbit. Yes, you start getting closer to the object. But as you fall towards it, you’re going faster and faster. And unless you smash into the object, you’re going to fall around it, and then shoot upwards as fast as you fell downwards. And then you’ll fall downwards as fast as you shot upwards. Forever. Newton’s laws of motion mean there are only three types of orbits–parabolic, like when you throw a baseball in the air. Hyperbolic, like when something zooms past the sun and keeps going. And elliptical, of which circular is a special case of a perfectly symmetrical ellipse.
Of course, this ignores things like other bodies, and in real life objects orbiting the Earth are influenced by the Sun and the Moon, and the tiny amounts of gas in orbit around the Earth, and stray micrometeorites and so on.
But throw that hammer out the window of the ISS and it will return to exactly the same spot after orbiting the Earth exactly one time. Of course, you probably won’t be there at the same time, since you’ll be orbiting a little bit slower or faster, and so when you return to the exact spot where you threw the hammer the hammer will either be there later, or will have already been there. So you probably won’t bean yourself in the head with the hammer you threw yourself.
No, I meant throw it at the Earth, not sideways like somebody throwing their Big Mac wrapper out the window on the freeway. I’ll phrase it a different way. I’m floating in the Shuttle bay with the doors open and the shuttle is right-side-up relative to the surface of the Earth. I take a spare tile that is lying around and I just give it a gentle push out the bay door directly at the ground. It will orbit the Earth several hundred times before it finally hits the ground, won’t it?
It really does not matter which direction you push it. Orbital speeds are much much greater than any speed you generate with your push or toss. You just move the hammer into a slightly different orbit.
No. After the initial impulse you have imparted upon it, it will enter a new orbit with slightly modified eccentricity or apses, but unless you have completely canceled its orbital velocity at the point of ejection (or close enough that it intercepts the Earth’s surface or atmosphere) it will fall into a stable orbit that is just slightly different from that of the ISS.
Stranger
Oh, OK—I think I see it now. Since the tile is still moving at the same speed as the shuttle, it will want to climb back up to the same point where it was when I pushed it out the bay doors. So let’s say that I’m capable of throwing the tile 32 feet in the air if I were on the surface of the Earth. If I hurl it as hard as I can out the bay door, it will fall about 32 feet, come back up, and I’ll see it directly behind me about four seconds later. Do I have it now?
No. It will fall into an orbit that has a slightly difference eccentricity or apses (or more likely, both) than the one you are in, and will periodically re-intercept or come close to your existing orbit. Orbital mechanics is not intuitive unless you’ve spent considerable time studying the math.
Stranger
They tried transportation of white trash back in the days of sail, and it didn’t work, so there is no reason to think that it would work in the future days of solar sail.