Could we actually build an interstellar probe ?

[ZooNamedGames]

Could Voyager 1 be interstellar if we waited long enough?

It's definitely left Sol's SOI at this point, but as whether or not it'll leave the galaxy? I doubt it, it'll collide with some galaxy at some point and just be a comet to that galaxy. If it can get enough speed from a great number of low flying passes, then maybe... But that would require it to be in CONTROL. Not just flying aimlessly as it is.

To your question, yes. It will become interstellar. It will *potentially* (I'm guessing here). Left our solar system completely by the time I die. It's just a matter of time.

[Ralathon]

Could Voyager 1 be interstellar if we waited long enough?

Yea, Voyager is moving faster than the escape velocity of the sun. It is speeding away from us at about 17km/s

The closest star to the sun is about 4.2 lightyears away. That's about 4e13 kilometers. So if Voyager 1 was heading towards Alpha Centauri it would reach it in about 75k years.

Sadly, Voyager isn't heading towards Alpha Centauri. Closest it'll get to any star in the foreseeable future is Gliesse at a distance of 1.6 lightyears. Not that it matters, Voyager will run out of power before 2030.

[Seret]

Could Voyager 1 be interstellar if we waited long enough?

It's in interstellar space already. Eventually it'll swing close by something, it'll just be a looooooong wait.

[IronGremlin]

I think the real question is whether or not we have telemetry data accurate enough to make an inter-stellar orbital transfer...

We're all Kerbal players here, we know it's not just a matter of pointing at your target and hitting 'go.'

You have to take into account orbital mechanics - What's the center of gravity or respective stars are orbiting? The galactic center, but not exactly?

How are we going to fine tune our escape trajectory so that we don't spend absurd amounts of DV on mid-flight correction burns, when we're close enough to see how horrifyingly off-target we are?

Granted, we are pretty good at extrapolating telemetry data, but we're talking several exponential leaps past distances we've dealt with before - This is a non inconsiderable navigational hurdle.

[Ralathon]

I think the real question is whether or not we have telemetry data accurate enough to make an inter-stellar orbital transfer...

We're all Kerbal players here, we know it's not just a matter of pointing at your target and hitting 'go.'

You have to take into account orbital mechanics - What's the center of gravity or respective stars are orbiting? The galactic center, but not exactly?

How are we going to fine tune our escape trajectory so that we don't spend absurd amounts of DV on mid-flight correction burns, when we're close enough to see how horrifyingly off-target we are?

Granted, we are pretty good at extrapolating telemetry data, but we're talking several exponential leaps past distances we've dealt with before - This is a non inconsiderable navigational hurdle.

Actually, all these things are considerably easier with interstellar travel. The orbital period around the galactic core for the sun is about 220 million years. So if we plan to travel between the stars in a reasonable time frame they'll barely move relative to each other. This simplifies things to the point that it really is 'point and burn'.

Interstellar travel is more like the last 500 meters of a rendezvous than an interplanetary transfer.

[KASASpace]

If you want to get to a reasonable fraction of the speed of light, like 70%, then you need a mass fraction that is just GINORMOUS, even with antimatter.

So, probably not getting to .7c anytime soon, but if fusion is on its way like people say, we might get .1 or .2c. Orion could get to Alpha Centuari in ~130 years, if we build the interstellar version that's fast. Basically, it's possible, but the biggest obstacle is not mass fractions or speed, but POLITICS. Who's going to fund a .1c probe?

[CleverWalrus]

Yup, biomarker molecules can be detected in the atmosphere. Earth light has O2, O3, water vapor, and methane absorption lines that would be detectable for dozens of light-years by aliens utilizing the just the kind of technology we have today. These molecules, together, scream life- there is no known way for these molecules to coexist in large quantities outside of biological processes The JWST could possibly find an Earth-like planet with life, especially if they get that star shade made for it. It seems likely within 100 years we will have telescopes capable of detecting life on Earth-like planets out to 1000 light-years or more.

It gets better too- for example, it seems the spectral signature of chlorophyll is detectable in Earth light too- astronomers analyzed Earth shine on the Moon and found what appeared to be a weak signal from chlorophyll. Also, aliens looking at Earth would easily be able to tell our planet rotated in ~24 hours, by changes in the color and albedo, and graphing these. They could tell how much cloud cover Earth has, what percentage was land and what percentage was water. They could tell that some areas of land were brownish/orangish, while some were very green. With a really big telescope, of the kind we'll have in a few decades, they would be able to see the light pollution from our cities- for example, there is no reason a planet like Earth should have mercury emission lines, other than artificial lighting.

All this kind of information can be determined just by analyzing the light of a distant, point-source Earth. No need to resolve the disk.

A civilization 1000 light years away will not be able to see a lot of light pollution since they will see our planet as it was 1000 years ago.

Often we forget that we "scream" technology from a century or so, anything outside of 100 light years don't know it yet.

Anyway, the rest is 100% correct, in a few decades we should be able to clearly understand if a planet have life similar to what we know, the main problem is that we don't know if all life is like the one on our planet so we could ignore results of other kind of life.

[CleverWalrus]

If you want to get to a reasonable fraction of the speed of light, like 70%, then you need a mass fraction that is just GINORMOUS, even with antimatter.

So, probably not getting to .7c anytime soon, but if fusion is on its way like people say, we might get .1 or .2c. Orion could get to Alpha Centuari in ~130 years, if we build the interstellar version that's fast. Basically, it's possible, but the biggest obstacle is not mass fractions or speed, but POLITICS. Who's going to fund a .1c probe?

If reactionless drives become a reality like it sounds these days we could be able to easily achieve incredible speeds over long acceleration times and most of what now is "unpratical" will become "easy", then if we end up with a working alcubierre drive it open room for human exploration of the universe.

Let's hope we can see something so incredibly amazing within our life span

[Sky_walker]

at this point, but as whether or not it'll leave the galaxy?

It won't even leave our galactic arm, and you're wondering if it'll leave the galaxy. Hehehe, good joke.

If reactionless drives become a reality like it sounds these days we could be able to easily achieve incredible speeds over long acceleration times and most of what now is "unpratical" will become "easy",

Reactionless drives won't make anything "easy" nor allow you to suddenly jump on interstellar bandwagon nor have a flying car. Reactionless drives are not an universal answer to everything. Never were.

In a best case - they'll simply migrate problems. Instead of thinking about fuel mass - you'll wonder about mass of your energy generators (be it solar panels or anything else) and the drives themselves.

You won't be able to achieve any "incredible speeds" if you won't be able to power your be-all-end-all drive.

then if we end up with a working alcubierre drive it open room for human exploration of the universe.

Again: energy. Only with Alcubierre drive it gets even more complicated than other types of proposed reactionless drives cause you need negative energy.

Even if we assume that Alcubierre drive can be constructed (which still is a huge unknown) - it'll still require enormous amounts of energy to transport anything in reasonable size - in fact: such an enormous energies might be involved that Dyson Sphere build around our sun might not be enough to power it.

Edited August 2, 2014 by Sky_walker

[SargeRho]

Spheres of Influence are a real thing - it's the oblate spheroid region around a celestial body where that body's gravity is the strongest one.

[KvickFlygarn87]

I'm pretty sure we already have

[XIRA]

It won't even leave our galactic arm, and you're wondering if it'll leave the galaxy. Hehehe, good joke.

Thats not entirely true. It might go intergalactic when the milky way collides with the Andromeda galaxy