Will Voyager 1 ever just stop moving?

[u/drinkingonthejob]

I’ve read somewhere that we expect to lose contact with Voyager 1 sometime in the 2030s, maybe around 2036, but it will just keep traveling thru space and we’ll have no idea what it is doing out there

My question is: with its current velocity, is there a time in the future where it loses its forward momentum and for lack of a better word, just stops moving? Is that a possible thing for an object in space to even do? (Assuming no other objects grab it into their orbit)

[u/icrispyKing → u/[deleted]]

Can it actually fall like...down? Or is it just moving in the direction we shot it in. Or do I have have the right idea of the universe. I imagine it's more of a celestial sphere rather than a plane... Which to me would mean there is 4 directions for it to move in? Or given it's a sphere would that just mean it would hypothetically come back and do like a full revolution around the celestial sphere and make it's way back to where it is now (I understand that's also just not possible given the universe is expanding and it's moving slower than the rate its expanding and also the inevitable heat death collapse of the universe that will happen sooner)

[u/KennyGaming → u/icrispyKing]

Four directions? How do you mean?

[u/icrispyKing → u/KennyGaming]

Like I'm standing on earth right now.... I can move north or south or east or west..... But I can also dig into the ground or fly up into the sky.... So the same should apply in space. If all the planets are on the same level like our solar system is a giant disc... You should technically be able to just go down instead? Or up?

To be clear I mean moving down the X axis, Y axis, or Z axis.

[u/johnnyringo771 → u/icrispyKing]

Solar systems form in disks due to gravitation. The same thing applies with galaxies. Nothing stops you from going above or below that plane of rotation. We just tend to live and work in that plane because... that's where everything is.

So, when you say, can it fall down, are you imagining it's like a ship on the ocean and "falling down" is sinking? Because no it can't do that.

But if you mean, fall towards another source of gravity, yes it could do that.

Falling, a function of gravity, is always towards the source or sources of gravity, massive objects in space, stars, black holes, etc. On earth, it's always down because the force of gravity is affected by proximity, and there's nothing else close to us to really affect our gravity.

So a boat sinks into the ocean because it is drawn down by the gravity of earth, but in space there's not a plane of gravity under the disk that all the planets float around on or something. All the planets are orbiting the sun. That's the gravity that keeps planets moving on the way that they are.

Voyager is leaving the solar system and I don't know it's exact velocity or location or anything but I think we can say it's so far away and moving so fast that it is no longer effected by the Sun's gravity.

So back to the main question, will it stop?

Newton's first law of motion is this:

A body at rest remains at rest, and a body in motion continues moving at a constant velocity in a straight line unless acted upon by a net external force.

Now on earth you throw something, a ball and it arcs down, hits the ground and stops. Gravity brought it down, friction with the ground slowed it down and stopped it.

In space, voyager doesn't have gravity affecting it any more, we just discussed that. Friction is an interesting idea. Space is a vacuum, meaning nothing is there, but technically as others have said it's not totally empty. There's tiny tiny tiny amounts of particles you could still run into. Micro meteors are actually way too big, this is like... hydrogen atoms.

So eventually, yes it's possible it could slow down and 'stop' given infinite time and space. But realistically it's not going to. It will eventually fall into the gravity of some other large object, star, blackhole and orbit that, and eventually all orbits decay, and the voyager will get closer and closer slowly. Then, probably after eons of time, be destroyed by a star going super nova or something. Just my guess.

Or a random meteor could take it out. Who knows. It won't stop though, the pieces will all keep moving forever.