How Long Would It Take Voyager 1 To Reach The Edge Of Our Galaxy?

[Mintaka]

I hear Voyager 1 is now nearing the edge of our solar system.

I hear she is travelling at 17/km per second which I think is 61,000 km/h ??

 

At this speed, assuming her speed is constant, how long would it take her to reach the edge of our galaxy?

 

And once she did, would she be able to leave our galaxy ?

 

Thank you folks.

[geko]

Wow that was actually harder than i thought it was gonna be, and to be honest i'm not sure if i'm right but wanted to have a go anyway. This is what i came up with.

 

Assume the milky way is 100k light years in diameter. Assume the sun is 27k light years from the centre. That's 23k light years from the edge, which is 230000 trillion kilometers. At voyagers present speed of 17 kilometers/sec it will take 37 trillion hours ~ 4 billion years.

 

Maybe someone with more savvy will correct me mind.

[Mintaka]

Thank you good work Geko, it sounds good to me, but I am once again in awe of this universe. We see thousands of galaxies the same size as ours with Hubble, we see them as tiny disks and spirals and yet...it would take 4 billion years to reach the edge of ours, going at 37,000 mph.

 

Amazing.

[CraigD]

Wow that was actually harder than i thought it was gonna be, and to be honest i'm not sure if i'm right but wanted to have a go anyway. This is what i came up with.

 

Assume the milky way is 100k light years in diameter. Assume the sun is 27k light years from the centre. That's 23k light years from the edge, which is 230000 trillion kilometers. At voyagers present speed of 17 kilometers/sec it will take 37 trillion hours ~ 4 billion years.

 

Maybe someone with more savvy will correct me mind.

If Voyager 1 were headed directly outward toward the edge of the Milky Way along its plane, geko’s approach would be right.

 

His data on the diameter of and our position in the Milky Way looks right to me, but I think he’s made a unit mistake – a light year is exactly 9,460,730,472,580,800 m, roughly 10 trillion km, so his result should have been 230,000,000,000,000,000 km / 17 km/s = 14,000,000,000,000,000 s = 400,000,000, not 4,000,000,000 years.

 

However, Voyager 1 isn’t heading for the close edge of the galaxy along its plane, but nearly toward its center at a pretty steep “upward” angle – its galactic coordinates are about 33° longitude, +28° latitude (galactic center’s are 0° Long 0° Lat). Taking this into account, it should reach the top (or North) edge of the galaxy, 400 to 500 lys distant, in about 300,000,000,000,000 s = 10,000,000 years.

 

If by edge of the galaxy, you mean edge of its disk, not its top of bottom edge, it’ll take Voyager 1 about 4,000,000,000 years to get across the galaxy and beyond the far edge. Although Pioneer 10 is moving a bit slower than Voyager 1 (12 vs. 17 km/s), it’s headed almost directly toward the near edge of the galaxy, galactic coordinates 181° Long -20° Lat. It should pass the edge of the galaxy in about 643,000,000 years.

 

Another thing to keep in mind is, like our solar system, the galaxy is surrounded by an extended envelope of denser than surrounding gas and dust, so its "true" edge is some thousands of light years beyond the last of its stars.

 

Somebody better check my arithmetic, too – it’s easy to make big mistakes working with such astronomical numbers. :)

[Mintaka]

Thanks Craig. I guess if it will take Voyager 1, 400 million years, it could be kind of immaterial for us, and if she ever gets picked up by some distant cosmic beachcomber, she may be looked at like we look at a dinosaur fossil.

 

I suppose too, after such time and distances in space, she will have eroded away or been obliterated by cosmic grit.

 

Please check the link below to the Hubble image of the M81 galaxy. It seems like a galaxy similar to our own, M1 I believe.

 

What are we looking at here, when we look at the faint whispy milky foggy spiral arms ? Is each millimetre of this whispy 'fog' made up of millions of stars?

 

I am starting to think that astronomy is a subject which should have a mental health warning attached to it. I'm guessing that many astronomers

 

live close to the border of sanity, dealing with such scales and distances.

 

On the scale of the galaxy, could we say the earth is similar in size to an atom in a molecule? Or a molecule of air inside a football?

 

Perhaps you better not tell me...I am already reaching for the anti-depressants ;-)

 

Spiral Galaxy

[geko]

Oh the elusive decimal on big numbers :)

 

 

...or is that just my excuse ;)