Two straightforward Voyager questions

Two straightforward Voyager questions

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Eighteeteewhy

Original Poster:

7,259 posts

175 months

Thursday 23rd July 2015
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If a similar machine to our Voyagers but from some far away civilisation passed between the Earth and the Moon would we detect it?

If/when Voyager makes it to another planet system and passes near a huge planet could it get caught up in its gravity or even in the systems star gravity and just stay there forever going around and around?



CrutyRammers

13,735 posts

205 months

Thursday 23rd July 2015
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Interesting smile

1 - quite unlikely, I'd imagine. They aint very big, so unless it was transmitting something my guess would be that there's very little chance. And even if it were, not much more of a chance.

2 - yes, certainly possible. Or it could just get swung out onto a different path.

Eric Mc

122,861 posts

272 months

Friday 24th July 2015
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More likely get deflected rather than captured.

Prof Prolapse

16,160 posts

197 months

Friday 24th July 2015
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Eighteeteewhy said:
If/when Voyager makes it to another planet system and passes near a huge planet could it get caught up in its gravity or even in the systems star gravity and just stay there forever going around and around?
I thought everything caught in orbit eventually crashed into the object it is orbiting?

Bits in space and all that crap slowing it down.

Sheets Tabuer

19,648 posts

222 months

Friday 24th July 2015
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Eighteeteewhy said:
If a similar machine to our Voyagers but from some far away civilisation passed between the Earth and the Moon would we detect it?

If/when Voyager makes it to another planet system and passes near a huge planet could it get caught up in its gravity or even in the systems star gravity and just stay there forever going around and around?
1)Only if it was transmitting signals we could detect, voyager will take around 70k years to reach the nearest star so will be long dead by then.

2) Unlikely, it could get close enough to have it's trajectory changed but it is travelling at 17km/s so you would need to decelerate the probe in relation to the planets escape velocity in order to achieve orbit.

Jupiters escape velocity is 59 km/s but gravity weakens as you get further from the planet and then we get into angular momentum.

Not a physicist this is just my understanding so I could be completely wrong hehe

Einion Yrth

19,575 posts

251 months

Friday 24th July 2015
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Prof Prolapse said:
I thought everything caught in orbit eventually crashed into the object it is orbiting?
The moon gets further from the Earth at a rate of about 3.75cm per year, so...

Prof Prolapse

16,160 posts

197 months

Friday 24th July 2015
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Einion Yrth said:
Prof Prolapse said:
I thought everything caught in orbit eventually crashed into the object it is orbiting?
The moon gets further from the Earth at a rate of about 3.75cm per year, so...
I don't envision most satellites cause a tidal effect.

If I'm satisfying pedantry, the point was more that the balance between gravity and forward momentum cannot be maintained. So there is no "forever" in context.




andrew_huxtable

936 posts

195 months

Monday 27th July 2015
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My maths is shocking, but the last time I checked the furthest out probe was doin 18 kilometres a second, and at that rate I had a rough estimate of about 750 thousand years before it come across anything interesting.

One thing for sure is that little probe will probably outlive humankind, I doubt we will ever catch up with it

MrBrightSi

2,914 posts

177 months

Thursday 6th August 2015
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From wikipedia so im sorry:
The record is constructed of gold-plated copper. The record's cover is aluminum and electroplated upon it is an ultra-pure sample of the isotope uranium-238. Uranium-238 has a half-life of 4.468 billion years. It is possible (e.g. via mass-spectrometry) that a civilization that encounters the record will be able to use the ratio of remaining uranium to daughter elements to determine the age of the record.

So 750k years is nothing in the grand scheme of things, if this record is found it has over 4 billion years of shelf life.

However, 4 billion years will mean earth will be a melted ball as our sun will of started to die and expand.

I just think it's a wonderful and beautiful thing that we as a species has sent out into space evidence of our existence that might outlast us, it might be there when man has evolved into the next step.

Caruso

7,469 posts

263 months

Sunday 9th August 2015
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1. I think we would detect it. I heard on a Nasa video that they reckon they know about 90% of objects >10cm in near earth orbits.

2. I think it could end up orbiting a star in a highly eliptical orbit. Unlikely to orbit a planet though.

KaraK

13,280 posts

216 months

Monday 10th August 2015
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Caruso said:
1. I think we would detect it. I heard on a Nasa video that they reckon they know about 90% of objects >10cm in near earth orbits.

2. I think it could end up orbiting a star in a highly eliptical orbit. Unlikely to orbit a planet though.
1. There's a world of difference between something in a near-earth orbit and just generally passing through the solar system though! It's like trying to keep track of a post-it note on your desk vs a post-it note somewhere in the country smile

2. My rudimentary physics would agree with you on that one smile

Moonhawk

10,730 posts

226 months

Monday 10th August 2015
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It's possible - although we probably wouldn't know what it was and would likely be labelled as a near earth asteroid.

Even our own spacecraft are misidentified as near earth asteroids sometimes:

https://en.wikipedia.org/wiki/Rosetta_(spacecraft)...

Tango13

8,934 posts

183 months

Tuesday 18th August 2015
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Apparently alien life forms have already encountered Voyager, their first message was...

'Send more Chuck Berry!!'

wink

Halmyre

11,567 posts

146 months

Thursday 20th August 2015
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Tango13 said:
Apparently alien life forms have already encountered Voyager, their first message was...

'Send more Chuck Berry!!'

wink
No probs, here's 'My Ding-A-Ling'

That'll learn them...

Guvernator

13,446 posts

172 months

Friday 21st August 2015
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While I think it's genuinely exciting that we've sent a man made object on a journey that will probably outlast us and end up with the object being light years away (if it isn't destroyed in the interim) I'd just like to remind you all of this.

"Pathetic earthlings. Hurling your bodies out into the void, without the slightest inkling of who or what is out here. If you had known anything about the true nature of the universe, anything at all, you would've hidden from it in terror." - Ming the Merciless

biggrin

anonymous-user

61 months

Friday 21st August 2015
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No-one would have believed, in the last years of the nineteenth century, that human affairs were being watched from the timeless worlds of space. No-one could have dreamed that we were being scrutinized, as someone with a microscope studies creatures that swarm and multiply in a drop of water. Few men even considered the possibility of life on other planets. And yet, across the gulf of space, minds immeasurably superior to ours regarded this earth with envious eyes, and slowly and surely, they drew their plans against us…




oooooorrrraahhhhhhhhhh!



;-)

MartG

21,250 posts

211 months

Friday 21st August 2015
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ash73 said:
I'm inclined to agree. Including a map showing where we are wasn't very smart, although the chances of it being intercepted are tiny. We should find a way to shield our transmissions from Earth, but nobody will take that seriously until it's too late.
Me too. It's all very well saying that any civilisation that can detect us will either be benevolent or unable to reach us due to the vast distance - but you are betting the existence of the entire human race on those assumptions on the basis of no data whatsoever.

Maybe I'm a touch paranoid but I think we'd be safer assuming the worst with the possibility of being pleasantly surprised rather than the rose-tinted-glasses approach.