Voyager 1 - Living Up To It's Name

[Knight of Clear Skies]

This has been talked about and disputed for a few months now, but it looks like the results are now in. Voyager 1 has become the first space probe to now leave the Solar System and break into interstellar space, at a distance of 17 light hours from the Sun. That's some journey, 43 years in the making.

(It's still well within the Oort cloud, but it's passed out of the region dominated by the Solar wind, and is providing the first direct measurements of the interstellar medium.)

[Pig]

That is a remarkable achievement well done to voyager and its developers

[Paul M]

In the current world it's not big news but to those of us who remember it's launch and mission highlights it's been one hell of a voyage!

The voyage is barely begun. We have been interstellar travellers for barely a heartbeat.

More exciting than it's beginning is the journey's end. I wonder where that will be?

[Black Knight]

A real testament to 1970s engineering.

[nameunknown]

its a start...

[DrRobin]

Gone, but not forgotten. I can remember the launch and all the photos both Voyagers sent back as they passed by the planets.

Robin

[Monty]

Epic, truly epic!

[Red Coffee]

Will Voyager rot away in space or drift on for eternity?

[DaveS]

Not rot, no, but I expect both craft will be slowly eroded by the interstellar environment of dust and charged particles that they will plough through over the next few million years.

[Paul M]

Will Voyager rot away in space or drift on for eternity?

The interstellar environment is rather benign. It's effectively a vacuum. Voyager will go a very long time before being significantly degraded and eroded by "weathering".

I imagine it's doomed to wander the stars for an eternity.

[Red Coffee]

If it doesnt run into anything will it reach another star before eroding?

I'm curious as to its final destination?

[crashtestdummy]

Have they released what it's next target would potentially be?

[foundaplanet]

This has been talked about and disputed for a few months now, but it looks like the results are now in. Voyager 1 has become the first space probe to now leave the Solar System and break into interstellar space, at a distance of 17 light hours from the Sun. That's some journey, 43 years in the making.

(It's still well within the Oort cloud, but it's passed out of the region dominated by the Solar wind, and is providing the first direct measurements of the interstellar medium.)

This bit is bad news for me as it means I am 7 years older than I thought I was..

[Naemeth]

Wow, it's really done it. Interstellar space travel awaits, and lets hope it can give us another decade of good data before it finally loses power.

[Pig]

It would be scary if it came back around from behind us next week

[Paul M]

The Wiki's for Voyagers 1 &2 make interesting reading.

Voyager 2 should pass within 4.3 l/y of Sirius in 296000 years unless alien salvors weigh it in first.

I'll post an update to this thread nearer the date

[kirkster501]

Electronics reliability is trully amazing. I have a portable radio/cassette from 1977, a Sankyo (yes, with a "K" in the middle so NOT Sanyo) my dad bought me for my 10th birthday. Its been running none stop for the last 20 years as a music on hold device. Consumes about 2w and has never missed a beat.

Voyager is truly one of the greatest feats of mankind IMO.

[DazC]

Do you think we, as a race, will ever manage to build a spaceship and catch up and even recapture voyager 1? Or 2 for that matter?

It would make one hell of a museum piece.

D.C

[ScottS]

It would be scary if it came back around from behind us next week

Would be even more scary if "something" brought it back!

[Paul M]

Do you think we, as a race, will ever manage to build a spaceship and catch up and even recapture voyager 1? Or 2 for that matter?

It would make one hell of a museum piece.

D.C

I'd like to think that future generations, given the ability of interstellar travel, would leave it to go on its way, carrying the hopes and imaginations of their forebears with it...

[Pig]

Would be even more scary if "something" brought it back!

lol now that would be epic

[nerointegrale16v]

[nerointegrale16v]

[baggywrinkle]

From New Scientist..

NASA says Voyager 1 has left the solar system, honest

• 19:16 12 September 2013 by Michael Slezak and Victoria Jaggard
  
• For similar stories, visit the Solar System Topic Guide
  

Voyager 1's on-again, off-again relationship with the solar system would give any celebrity couple a run for their money. But with the evidence mounting, the science team in charge of the NASA spacecraft is at last ready to bid Voyager 1 farewell. What's more, they have placed a date on the probe's exit from the solar system: 25 August 2012.

The solar system is encased in a magnetic bubble blown by the constant wind of charged particles streaming from the sun, called the heliosphere. Since 1977 Voyager 1 has been cruising away from Earth towards the edge of that bubble, the heliopause. But for the past few years the spacecraft has been a bit of a tease, showing repeated but unconfirmed glimmers that it may have crossed over into interstellar space.

Now, readings taken over the past year show a definite increase in the density of charged gas around the spacecraft. This is a telltale clue, because plasma density in interstellar space should be much higher than it is inside the solar system's boundary zone. Working backwards, the Voyager team says a noticeable density increase started in August 2012 – the same time that Voyager 1 also recorded a suspicious change in its sightings of high-energy particles known as cosmic rays.

The only hitch is that the team had been expecting a third sign of a crossing: a change in the direction of the surrounding magnetic field. Although such a shift has not yet appeared, the consensus of the Voyager team is that the craft has in fact made its grand exit, and we simply do not understand how magnetic fields behave at the very edge of the solar system.

"Speaking for myself and my co-authors, we certainly believe we have crossed the boundary," says Voyager team member William Kurth at the University of Iowa in Iowa City. "The measurement of these very high densities is the smoking gun."

Highs and lows

Voyager fever began building in 2004, when the spacecraft crossed into a border zone – the heliosheath – where the solar wind suddenly slows to a crawl. Expectations began mounting that Voyager 1 was close to popping out of the sun's sphere of influence and into the open waters of interstellar space. Multiple teams on and off the mission have been scouring data from the craft's instruments looking for hints of a crossing. Some have even argued it happened before, although until now most of Voyager's lead scientists remained unconvinced.

Things changed on 25 August last year. The cosmic rays the craft saw coming from the sun seemed to just about disappear. They were replaced by galactic cosmic rays, which come from sources outside the heliosphere. That was enough for some scientists to declare that Voyager 1 had left the solar system.

But theory predicts that at the heliopause, the direction of the magnetic field carried by the solar wind should switch to that carried by the charged particles flying through interstellar space. At the time the Voyager team countered that they had not yet seen the magnetic field change direction, so Voyager 1 was still in the solar system's embrace.

Cosmic violin

The latest measurements come from an instrument on Voyager 1 that detects oscillations in the surrounding plasma, allowing it to infer density. These plasma oscillations can be triggered by extreme events on the sun that send electron beams coursing through the solar wind. When these beams interact with the interstellar plasma, they can create oscillations in a particular frequency range.

"If you think of a plasma oscillation as a violin string, it's the vibration of the string that Voyager has measured," says Kurth.

The trick is that the waves can take up to 400 days to propagate out to the heliopause, so readings have to be carefully timed to catch their effects that far away. New measurements of the oscillations taken during two periods, October to November 2012 and April to May 2013, show that plasma density has been increasing steadily and is now about 30 times higher than that inside the heliosheath. Extrapolating backwards, the Voyager team says the increase must have started on about 25 August 2012, coinciding nicely with the changes in cosmic rays.

The idea that you need to see a concrete change in the magnetic field rests on the assumption that there is a single, well-defined boundary between the heliosphere and interstellar space, but perhaps that is not necessarily so, the team says.

"What I don't think we've understood up until now is whether there is a dramatic switch or whether there could be other physics going on that involves draping of the interstellar fields around the solar boundary, or perhaps some intertwining of the field lines," says Kurth. "My interpretation is that the heliopause is not as absolute and simple as we imagined it might be."

Hope for change

As far as we understand what the boundary of the solar system is, Voyager 1 has gone past it, agrees Simon O'Toole from the Australian Astronomical Observatory in Sydney, Australia. "The problem is we really don't understand magnetic fields very well," he says. How two independent magnetic fields interact in three dimensions and over time is incredibly complex. There are competing theories about what will happen, and the uncertainty of what is happening at the heliopause highlights our confusion.

Voyager 1 should eventually show a change in magnetic field direction as it gets further form the border, and that will help refine our understanding, says O'Toole. For instance, how abruptly the field changes will help rule out certain models and refine others. "When the field does change, astronomers will be very excited."

But time is running out: Voyager 1 is getting low on juice. In 2020 it will start rotating the power through its various instruments to save energy. By about 2025, Voyager 1 will die.

Journal reference: Science, DOI: 10.1126/science.1241681

[Stu]

It's an incredible achievement, and one that I've been following for much of my life - I was seven when they launched :-).

One point which I came across yesterday is that although Voyager 1 is now beyond the sun's influence in terms of solar wind/ magnetic fields etc, it is still inside the Oort Cloud so is very much still within zone where the sun's gravity dominates. It won't get through the Oort Cloud for another 14 to 28,000 years! Pretty mind boggling :-)

Stu