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Starfleet Veteran
Join Date: Jun 2012
Posts: 2,630
# 8
07-02-2013, 11:16 PM
Originally Posted by felixhex View Post
This kind of stuff fascinates me. Right now there is a machine made by us flying through space 11 billion miles from Earth. And it may be exiting our solar system and hitting interstellar space. That's so freaking awesome! I have a question, does the voyager 1 speed increase as the distance between it and our Sun increases? If so, once it hits interstellar space, where there should be no kind of gravitational pull, would it be able to go even faster? My thinking is we don't really know how far this thing can get before 2020 if that is the case. Whats the nearest system to us? No one make fun of me but is it Alpha Centauri? Whatever it is we should go there next.
No, Voyager hasn't been accelerating for a very long time, since it separated from its launch vehicle. It only has some maneuvering and alignment thrusters on itself, and those were out of fuel years ago. There is no force to accellerate it - the force of the solar wind on it is far less than the force of the sun's gravity slowing it.

It's actually losing speed, since even outside the heliopause it's still in the sun's gravitational domain. The Oort cloud's inner range is believed to be orbiting about 50,000 AU from the sun - Voyager is not quite 125 AU out and going ~3.5 AU/year. It's over escape velocity, so it will escape, but it will continue to slow down for ten to twenty thousand years.

It's going in the wrong direction for Alpha Centauri. It's heading towards Ursa Minor, the next star it will encounter will be a 1.6 light year flyby Gliese 445, with closest approach estimated for the year 40272.

Interestingly, it will be more that Gliese 445 will be flying by Voyager - it's moving much faster than Voyager is, and when Voyager and Gliese meet, they'll be closer than Alpha Centauri, about 3.45 light years away.

At that time it will be the second closest star to the sun, Ross 248 will be even closer, and coincidentally will have a similar encounter with Voyager 2 around the year 42189, just over 3 light years away.