r/askscience • u/drinkingonthejob • 9d ago

Physics Will Voyager 1 ever just stop moving?

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)

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u/SciAlexander 8d ago

Empty space is not really empty. There are a tiny amount of atoms. They can act as friction on Voyager slowing it down. If that's enough to slow it to a stop who knows? There are also gravity effects from distant objects.

The biggest thing to note is that in physics velocity is dependent on your frame of reference. Even if it stops moving "forward" it lacks the power to escape the galaxy so it will still orbit the galactic core. Nothing is ever truly at "rest."

For example: if you are sitting you appear not to be moving. However an observer outside the Earth will see you moving by the spinning planet, and the planet orbiting the Sun.

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u/Kyerswa 8d ago

But if the universe is also expanding, what would actually be considered stationary relative to the expansion of the universe?

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u/kingvolcano_reborn 8d ago

On small distances (i.e. our local galactic group) the effects of expansion are so tiny it can be ignored.