Voyager 1 is currently travelling at 38000 miles per hour in interstellar space. Of course, in a few years time all its functions will eventually shut down but it will remain at the same velocity of 38000 miles per hour.

My question is, will Voyager 1 ever stop? My thoughts are that there are no forces acting on voyager 1 in outer space hence nothing to apply pressure to the parts to make the explorer loose velocity or break up. In theory, if Voyager 1 never crosses paths with any object in outer space (star, comet etc) then will it keep on going until infinity?

I have not been studying Physics for long so please correct me if there is a major flaw in my suggestions.

  • 2
    $\begingroup$ Stop with respect to what? $\endgroup$ – Conrad Turner May 9 '15 at 17:57
  • $\begingroup$ There are actually gravitational forces acting on Voyager. It is bound to the Milky Way galaxy and it will occasionally get into close encounters with stars. In these encounters, on average it will gain energy until its velocity gets larger than the escape velocity, it will then move into intergalactic space. $\endgroup$ – Count Iblis May 9 '15 at 18:19
  • $\begingroup$ @CountIblis There is still a chance that some celestial object might capture it someday! - not collide rather put the voyager into one of its orbits. $\endgroup$ – Yashas Aug 7 '16 at 6:31

There are forces of gravity everywhere, even in the weightlessness of space, there's always gravity. Orbits, like the earth around the sun or the satellites we launch into orbit around the earth, or moon around the earth are a kind of balance between gravity and velocity.

Voyager 1 isn't in orbit, (It is around the Milky-way, but lets ignore that for now) it's flying out of the solar-system at 38,000 MPH so in essence, your question is about escape velocity from the Sun.

Voyager is currently about 131 Astronomical Units from the Sun.

Source: http://voyager.jpl.nasa.gov/where/

At 131 Astronomical Units, the escape velocity from the sun is a bit under 10,000 MPH, so the answer to your question is no it won't stop, relative to the sun. It'll slow down, but it won't slow down any more than 28,000 MPH, at least until it gets close enough to another star to have a measurable impact on it's velocity.

If it meets a dual star system or star/planet combo (less likely), it would get a gravity assist either speeding up or slowing down. A star will also likely change it's direction, but, of-course, it will be long out of fuel by then.

If it was flying at a little bit under 10,000 MPH, it would eventually slow down close to 0 velocity relative to the sun, but it wouldn't ever actually "stop", it would either gradually escape or gradually begin to fall back - either into an orbit or back into the sun. (I can run the numbers with more accuracy if you like).

  • 1
    $\begingroup$ Since it is not likely to be heading radial away from the sun, it will never have a velocity of 0 m/s. There will always be tangential movement. $\endgroup$ – LDC3 May 9 '15 at 20:04
  • $\begingroup$ I lightly touched on that with "wouldn't ever stop" and "fall back into either orbit or back into the sun", but, you're right. Voyager almost certainly has enough tangential velocity that if it didn't have escape velocity it would fall into an orbit, not into the sun. $\endgroup$ – userLTK May 9 '15 at 23:44

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.