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Voyager 1 has left the solar system

307 points| j4mie | 13 years ago |agu.org | reply

63 comments

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[+] js2|13 years ago|reply
Previous times it has left:

- https://news.ycombinator.com/item?id=4867577 (106 days ago)

- https://news.ycombinator.com/item?id=4619731 (165 days ago)

- https://news.ycombinator.com/item?id=4483757 (195 days ago)

Seems like we're still not sure it's left due to lack of agreement on what constitutes leaving:

However, Webber notes, scientists are continuing to debate whether Voyager 1 has reached interstellar space or entered a separate, undefined region beyond the solar system.

[+] ChuckMcM|13 years ago|reply
There was some great discussion on what "leaving" might mean. And several theories about how that might show up on the instruments. Each time the instrument readings changed the scientists asked the question "So does this mean we're outside?" and in the ensuing discussion concluded that Voyager was still travelling through the boundary layer. An astrophysicist at Berkeley described it like leaving the ocean, when you're coming up on the beach but your still being washed over by waves are you in the ocean or not? Sometimes are sometimes not? Hard to say if you've never seen a beach and the only communication you get back from your probe is "I'm wet!","I'm not wet!"

This is likely one of the last "we think we're outside" papers I suspect. From the paper:

"This large decrease of ACR was preceded by 2 precursor temporary decreasesstarting on July 28th and August 14th. Thus V1 may have crossed a boundary, which itself was very sharp, at least 5 times during this time period"

(V1 = Voyager 1, ACR = Anomalous Cosmic Rays)

[+] guelo|13 years ago|reply
All four articles are talking about the same event that happened in August 2012. Today's article is a press release from the journal where the scientists published the data.
[+] cpeterso|13 years ago|reply
Maybe Voyager 1 keeps coming back then leaving again? :)
[+] gngeal|13 years ago|reply
"Seems like we're still not sure it's left due to lack of agreement on what constitutes leaving"

It's like leaving a country by staying in place while the borders are being redrawn on the map. ;)

[+] richeyrw|13 years ago|reply
Anyone remember that science fiction story, where the first ship to leave the solar system shatters some shell. And that it's later discovered that all stars have the same shell, which is impermeable from the outside. Sort of an enforced prime directive by unknown powers? This reminded me of that, and despite many searches I'm not getting any hits.
[+] TDL|13 years ago|reply
Not trying to troll, but how many times has Voyager left the solar system now? Do we even have a clear boundary of where the solar system ends?

edited for clarity.

[+] lftl|13 years ago|reply
Do we even have a clear boundary of where the solar system ends?

From what I gather as a layman, the answer to this is no, which in turn answers why Voyager has "left" numerous times. From the bit I've read Voyager has already forced some rethinking on what the edges of the solar system look like, and it may very well cause a few more.

[+] charonn0|13 years ago|reply
That's one of the things Voyager hopes to find out for us, I think.
[+] tragomaskhalos|13 years ago|reply
There really needs to be one of those signs, y'know, "You are now leaving the Solar System - please drive carefully"
[+] jjjeffrey|13 years ago|reply
If a spacecraft were to travel orthogonal to the plane on which planets orbit the sun, would it experience the heliosheath as it exits the solar system? For that matter, have there been any spacecraft launched that didn't travel on the orbital plane (ignoring earth-orbiting spacecraft)?
[+] rohansingh|13 years ago|reply
Yes, it would. The heliosphere is not spherical, but the solar wind exists in all directions. The orbital plane is due to conservation of angular momentum, a completely different phenomenon.
[+] novakinblood|13 years ago|reply
Maybe I'm just emotional today but the "Acknowledgments" section for the accepted journal was touching. I can only imagine what it felt like to complete the work of a good friend.
[+] netcraft|13 years ago|reply
I want to say there has been some discussion about space travel to other worlds and "leaving too soon", ie - if you launch today, a space craft that launches to the same destination a year from now would beat you there, because the technology would have progressed to the point that the later ship was much faster.

If we were to launch a state of the art probe today, how long would it take to get to where voyager 1 is now after 35 years of travel?

[+] ISL|13 years ago|reply
About the same. New Horizons was faster at launch, but the real boosts come from gravitational assists.

Clever choices of orbits buy you speed - stealing an infinitesimal fraction of Jupiter's momentum is much more efficient than any propulsion technology in use. If that ever changes, then "too soon" will have become reality.

From http://en.wikipedia.org/wiki/New_Horizons

"New Horizons is often given the title of Fastest Spacecraft Ever Launched, although the Helios probes are arguably the holders of that title as a result of speed gained while falling toward the Sun. New Horizons, however, achieved the highest launch velocity and thus left Earth faster than any other spacecraft to date. It is also the first spacecraft launched directly into a solar escape trajectory, which requires an approximate velocity of 16.5 km/s (36,900 mph), plus losses, all to be provided by the launcher. However, it will not be the fastest spacecraft to leave the Solar System. This record is held by Voyager 1, currently travelling at 17.145 km/s (38,400 mph) relative to the Sun. Voyager 1 attained greater hyperbolic excess velocity from Jupiter and Saturn gravitational slingshots than New Horizons. Other spacecraft, such as Helios 1 & 2, can also be measured as the fastest objects, due to their orbital velocity relative to the Sun at perihelion. However, because they remain in solar orbit, their orbital energy relative to the Sun is lower than the five probes, and three other third stages on hyperbolic trajectories, including New Horizons, that achieved solar escape velocity, as the Sun has a much deeper gravitational well than Earth."

[+] drcube|13 years ago|reply
For that matter, why did anyone buy computers when waiting just a little longer brought cheaper, faster, and better computers?

Well, for one thing, if nobody bought computers, they wouldn't have gotten any faster, since no one would have built them. And if nobody launched space probes, they wouldn't have gotten faster, because no one would have made them.

[+] rthomas6|13 years ago|reply
Conversely, this means that it's hard to find the optimal time of launch, since waiting would always provide a better launch in the future.
[+] meerita|13 years ago|reply
Maybe someone with experience in the field of communications and space can clarify my doubts: how we can improve the flow of data transmission to Earth? Imagine a string of satellites that communicate with each other so that the message reaches the earth faster distributed way. Now it seems that communications between satellites and Earth are slower and it has greater delays.
[+] kenj0418|13 years ago|reply
Maybe I'm not understanding your question, but adding intermediate satellites/probes wouldn't improve the speed of communications. The limiting factor is the speed of light. Adding additional hops in between would just add a slight processing delay, but definately not change the overall latency. Voyager is very far away and it's going to take a while to talk to it no matter what you do.
[+] kibwen|13 years ago|reply
I don't think this is anything new? We've had reports for over a year that Voyager has been getting anomalous readings. Whether or not that indicates having "left the solar system" is still a matter of debate (unless this article is trying to say that the debate has been settled), although it's certainly still exciting.
[+] anigbrowl|13 years ago|reply
When it is finally agreed that it has left (which presumably will occur within the next year or two), What Then?

I'm not hopeful that we'll be surprised in a major by the data coming from outside the heliosphere; to be honest I'm a bit worried that a lack of novelty will increase public apathy - 'We made it out! ...and that's all folks, shows over.' It's a bit like the moon landings; having been there and run out of convincing reasons to go back, we're heading back to that situation of no living person having walked on the surface of another world (http://xkcd.com/893/).

Props to Elon Musk etc., but I'm not all that optimistic about private enterprise just filling this niche.

[+] sharkweek|13 years ago|reply
I'm sniping this from a reddit comment, but I'm also now (jokingly) hoping that Voyager just ends up hitting a spherical wall that's covered in painted stars and galaxies. Could you imagine the ridiculousness of that, and the conversations that would occur? Ah the potential hilarity...
[+] lukejduncan|13 years ago|reply
Just this morning I listened to the Voyager Engineering Team on an old NPR Radio Lab episode where the crew mentioned that every day they check their Google Alerts to see if Voyager has left our solar system. I imagine their celebrating today.
[+] celias|13 years ago|reply
CORRECTED PRESS RELEASE Please note that the headline on this release has been changed to better represent the findings reported in the study. New title - "Voyager 1 has entered a new region of space, sudden changes in cosmic rays indicate"
[+] lelf|13 years ago|reply
Besides ‘oh, how many times it will left it?’, I wonder why many find someone's (another) whining about google reader or new bugs in rails more interesting than this.
[+] alexkus|13 years ago|reply
From: http://www.bbc.co.uk/news/science-environment-21866532

The Voyager project scientist at Nasa's Jet Propulsion Laboratory, Ed Stone, said he wanted to see a reorientation of the magnetic fields around the probe before declaring it to be in interstellar space. This was a "critical marker", he added. "…that change of direction has not yet been observed."

[+] acchow|13 years ago|reply
Is the change in the magnetic field direction sudden? Or gradual?
[+] raverbashing|13 years ago|reply
Beyond the discussion of 'how many times it has left already' I wonder what's the next Voyager spacecraft.

New Horizons certainly looks like it's going to help, it's a flyby mission to Pluto, and it's going faster than Voyager 1/2 apparently (haven't checked)

With modern equipment and transmission technology, hopefully it will help solve part of the mystery (or get its circuits fried with excess radiation outside of the solar system - too far fetched?)

[+] ndonnellan|13 years ago|reply
It was faster at launch, but V1 has gained more momentum.

From wikipedia: ' However, it will not be the fastest spacecraft to leave the Solar System. This record is held by Voyager 1, currently travelling at 17.145 km/s (38,400 mph) relative to the Sun. Voyager 1 attained greater hyperbolic excess velocity from Jupiter and Saturn gravitational slingshots than New Horizons '

[+] davidroberts|13 years ago|reply
It just thrills the heck out of me that this machine made 35 years ago and now flying 5 billion miles away is still communicating and doing science.
[+] liquidise|13 years ago|reply
While the Peer Review process is critical to the scientific method, it does slow down information.

To advertise this as a recent event when the article itself clearly states the measurements are from August 2012 is a tad disingenuous.

[+] ErikRogneby|13 years ago|reply
If the engineers that worked on Voyager 1 haven't won an award yet for the longevity and success of this program it's a damn shame.

It might be time to throw together a site chronicling old stuff in space that still works.

[+] angersock|13 years ago|reply
Only if it were a timeline, put alongside services that we use every day--I'd like to see the uptime on Curiosity or something next to this quarter's cloud outage.