Voyager 1's exit from our solar system
Discussion
I couldn't find a thread on this. My friend and I have been talking about it this morning.
It's alleged that Voyager 1, which was launched in 1977, is the first man-made object to exit our solar system doing so recently. Now apparently before NASA officially confirm that it has left, they have 3 criteria that needs to be met: the levels of cosmic rays from outside our solar system, a drop in charge particles from our sun and a change in direction of the magnetic field. The 3rd is yet to be confirmed but the first 2 have been.
There has been a lot of speculation and some information we have got back is confusing it would seem. I also found a website laying out what the 'golden record' is and what's on it. It's basically a layout of basic information on our solar system, humanity and some a priori truths like maths. You can see that here: http://goldenrecord.org/
Exciting stuff!
Oh here's one of the more informative articles:
It's alleged that Voyager 1, which was launched in 1977, is the first man-made object to exit our solar system doing so recently. Now apparently before NASA officially confirm that it has left, they have 3 criteria that needs to be met: the levels of cosmic rays from outside our solar system, a drop in charge particles from our sun and a change in direction of the magnetic field. The 3rd is yet to be confirmed but the first 2 have been.
There has been a lot of speculation and some information we have got back is confusing it would seem. I also found a website laying out what the 'golden record' is and what's on it. It's basically a layout of basic information on our solar system, humanity and some a priori truths like maths. You can see that here: http://goldenrecord.org/
Exciting stuff!
Oh here's one of the more informative articles:
Life's Little Mysteries said:
It will be another giant leap for mankind when NASA's Voyager 1 spacecraft becomes the first manmade object to venture past the solar system's edge and into the uncharted territory of interstellar space. But did this giant leap already occur?
New data from the spacecraft indicate that the historic moment of its exit from the solar system might have come and gone two months ago. Scientists are crunching one more set of numbers to find out for sure.
Voyager 1, which left Earth on Sept. 5, 1977, has since sped to a distance of 11.3 billion miles (18.2 billion kilometers) from the sun, making it the farthest afield of any manmade object. (It has 2 billion miles on its twin, Voyager 2, which took a longer route through the solar system.) Still phoning home (via radio transmissions) after 35 years, the Voyagers are the longest operating spacecraft in history.
For two years now, data beamed back to Earth by Voyager 1 has hinted at its close approach to the edge of the solar system, a pressure boundary called the heliopause. At this boundary, the bubble of electrically charged particles blowing outward from the sun (called the heliosphere) exactly counterbalances the inward pressure of the gas and dust from interstellar space, causing equilibrium between the two. But scientists have had trouble figuring out what, exactly, happens at or near this boundary — making it hard to tell whether Voyager has crossed it.
In 2010, Voyager passed the point where the solar wind, a stream of charged particles flowing outward from the sun, seemed to reach the end of its leash. The probe's detectors indicated that the wind had suddenly died down, and all the surrounding solar particles were at a standstill.
This "stagnation region" came as a surprise. Scientists had expected to see the solar wind veer sideways when it met the heliopause, like water hitting a wall, rather than screech to a halt. As Voyager scientists explained in a paper published last month in Nature, the perplexing collapse of the solar wind at the edge of the heliosphere left them without a working model for the outer solar system.
"There is no well-established criteria of what constitutes exit from the heliosphere," Stamatios Krimigis, a space scientist at Johns Hopkins University and NASA principal investigator in charge of the Voyager spacecraft's Low-Energy Charged Particle instrument, told Life's Little Mysteries. "All theoretical models have been found wanting."
However, Ed Roelof, also a space scientist at Johns Hopkins who works with Voyager 1 data, said that in any model of the heliopause, an object exiting through it should experience three changes: a sharp rise in the number of collisions with cosmic rays (high-energy particles from space), a dramatic drop in the number of collisions with charged particles from the sun, and a change in the direction of the surrounding magnetic field.
Based on two of those criteria, Voyager 1 looks as if it passed through the heliopause at the end of the summer. Since May, the spacecraft has experienced a steady rise in the number of collisions with particles whose energies are greater than 70 Mega-electron-volts, indicating they are probably cosmic rays emanating from supernova explosions far beyond the solar system. The level of these cosmic ray collisions jumped significantly in late August.
As first reported by Houston Chronicle science blogger Eric Berger, that jump coincided with another change in late August: The spacecraft also experienced a dramatic drop in the number of collisions with low-energy particles, which probably originated from the sun. [See graph]
In short, in late August, cosmic ray collisions sharply rose, and solar particle collisions sharply fell: two indicators of a transition through the heliopause.
"Most scientists involved with Voyager 1 would agree that [these two criteria] have been sufficiently satisfied," said Ed Roelof, also a space scientist at Johns Hopkins who works with Voyager 1 data.
To officially declare Voyager's crossing, the scientists need to check if the third condition holds. "Point 3 (the change in magnetic field direction to that of the interstellar field beyond the influence of the sun) is critical because, even though there is debate among astrophysicists as to what direction the field will lie in, it seems unlikely that it is the direction that we have been seeing at Voyager 1 throughout the most recent years," Roelof wrote in an email.
"That is why we are all awaiting the analysis of the most recent magnetic field measurements from Voyager 1. We will be looking for the expected change to a new and steady direction. That would drop the third independent piece of evidence into place — if indeed that's what will be seen," he said.
The scientists could not say when the magnetic field analysis would be finished. But when it is — and if it also indicates that the field's direction recently underwent a change — the world will know. "Once we have a consensus within the team we will inform NASA for a proper announcement," Krimigis said.
New data from the spacecraft indicate that the historic moment of its exit from the solar system might have come and gone two months ago. Scientists are crunching one more set of numbers to find out for sure.
Voyager 1, which left Earth on Sept. 5, 1977, has since sped to a distance of 11.3 billion miles (18.2 billion kilometers) from the sun, making it the farthest afield of any manmade object. (It has 2 billion miles on its twin, Voyager 2, which took a longer route through the solar system.) Still phoning home (via radio transmissions) after 35 years, the Voyagers are the longest operating spacecraft in history.
For two years now, data beamed back to Earth by Voyager 1 has hinted at its close approach to the edge of the solar system, a pressure boundary called the heliopause. At this boundary, the bubble of electrically charged particles blowing outward from the sun (called the heliosphere) exactly counterbalances the inward pressure of the gas and dust from interstellar space, causing equilibrium between the two. But scientists have had trouble figuring out what, exactly, happens at or near this boundary — making it hard to tell whether Voyager has crossed it.
In 2010, Voyager passed the point where the solar wind, a stream of charged particles flowing outward from the sun, seemed to reach the end of its leash. The probe's detectors indicated that the wind had suddenly died down, and all the surrounding solar particles were at a standstill.
This "stagnation region" came as a surprise. Scientists had expected to see the solar wind veer sideways when it met the heliopause, like water hitting a wall, rather than screech to a halt. As Voyager scientists explained in a paper published last month in Nature, the perplexing collapse of the solar wind at the edge of the heliosphere left them without a working model for the outer solar system.
"There is no well-established criteria of what constitutes exit from the heliosphere," Stamatios Krimigis, a space scientist at Johns Hopkins University and NASA principal investigator in charge of the Voyager spacecraft's Low-Energy Charged Particle instrument, told Life's Little Mysteries. "All theoretical models have been found wanting."
However, Ed Roelof, also a space scientist at Johns Hopkins who works with Voyager 1 data, said that in any model of the heliopause, an object exiting through it should experience three changes: a sharp rise in the number of collisions with cosmic rays (high-energy particles from space), a dramatic drop in the number of collisions with charged particles from the sun, and a change in the direction of the surrounding magnetic field.
Based on two of those criteria, Voyager 1 looks as if it passed through the heliopause at the end of the summer. Since May, the spacecraft has experienced a steady rise in the number of collisions with particles whose energies are greater than 70 Mega-electron-volts, indicating they are probably cosmic rays emanating from supernova explosions far beyond the solar system. The level of these cosmic ray collisions jumped significantly in late August.
As first reported by Houston Chronicle science blogger Eric Berger, that jump coincided with another change in late August: The spacecraft also experienced a dramatic drop in the number of collisions with low-energy particles, which probably originated from the sun. [See graph]
In short, in late August, cosmic ray collisions sharply rose, and solar particle collisions sharply fell: two indicators of a transition through the heliopause.
"Most scientists involved with Voyager 1 would agree that [these two criteria] have been sufficiently satisfied," said Ed Roelof, also a space scientist at Johns Hopkins who works with Voyager 1 data.
To officially declare Voyager's crossing, the scientists need to check if the third condition holds. "Point 3 (the change in magnetic field direction to that of the interstellar field beyond the influence of the sun) is critical because, even though there is debate among astrophysicists as to what direction the field will lie in, it seems unlikely that it is the direction that we have been seeing at Voyager 1 throughout the most recent years," Roelof wrote in an email.
"That is why we are all awaiting the analysis of the most recent magnetic field measurements from Voyager 1. We will be looking for the expected change to a new and steady direction. That would drop the third independent piece of evidence into place — if indeed that's what will be seen," he said.
The scientists could not say when the magnetic field analysis would be finished. But when it is — and if it also indicates that the field's direction recently underwent a change — the world will know. "Once we have a consensus within the team we will inform NASA for a proper announcement," Krimigis said.
That programme on BBC 4 was jaw dropping. I remember watching the first Star Trek movie and thinking "interesting story" but the reality of the mission turned out to be far more fantastic.
40,000 years until it enters another galaxy (if that's the correct term).
With the advances in technology since the build of V1 & V2, would another mission not be worth considering?
I'd seen something of the mission on the Brian wossisname Solar System series and I was out of my depth watching that.
OT but there have been some really excellent programmes from the beeb recently (on 2 or 4, obviously).
40,000 years until it enters another galaxy (if that's the correct term).
With the advances in technology since the build of V1 & V2, would another mission not be worth considering?
I'd seen something of the mission on the Brian wossisname Solar System series and I was out of my depth watching that.
OT but there have been some really excellent programmes from the beeb recently (on 2 or 4, obviously).
Smiler. said:
40,000 years until it enters another galaxy (if that's the correct term)
Not even close. That's the time it will take to pass the first nearby star.It would be hundreds of millions of years before it reached the nearest galaxy - if it was heading in that general direction - which it isn't.
smiler said:
With the advances in technology since the build of V1 & V2, would another mission not be worth considering?
Rocket technolgy has obviously moved on since the 1940s but the maximum speeds possible from rocketry have already been reached for the foreseeable future. Higher speeds in space will require more advanced technology - such as nuclear propulsion or ion drive. Ion drive is being devloped now and has already been used on a couple of small space probes.PS - the V1 was a crude form of pilotless jet aeroplane and had nothing really to do with rocket technology or spaceflight.
All joking aside I find it incredible to think that a man made object has traveled so far even more amazing that it is still transmitting data back to Earth. What sort of data is it able to transmit exactly?
Also hadn't realised that ion drive technology had developed so far. Am I right in saying that a Voyager probe equipped with an ion drive could in theory accelerate to a very high fraction of C and overtake it's relatively slow predecessors within a few years?
Also hadn't realised that ion drive technology had developed so far. Am I right in saying that a Voyager probe equipped with an ion drive could in theory accelerate to a very high fraction of C and overtake it's relatively slow predecessors within a few years?
Guvernator said:
All joking aside I find it incredible to think that a man made object has traveled so far even more amazing that it is still transmitting data back to Earth. What sort of data is it able to transmit exactly?
Also hadn't realised that ion drive technology had developed so far. Am I right in saying that a Voyager probe equipped with an ion drive could in theory accelerate to a very high fraction of C and overtake it's relatively slow predecessors within a few years?
The Voyagers have working instruments on board that can record the space environment around them - like magnetometers and particle detectors. It is these intruments that are picking up the sun's magnetic field and solar wind - and also cosmic particles coming in from deep space. The cameras were switched off permanently years ago - to save power.Also hadn't realised that ion drive technology had developed so far. Am I right in saying that a Voyager probe equipped with an ion drive could in theory accelerate to a very high fraction of C and overtake it's relatively slow predecessors within a few years?
Regarding ion drive, in theory the craft will keep accelerating as long as the ion motor keeps pushing. How long it can keep pushing is limited by the amount of fuel it can cary on board to feed the engine. So far, the ion powered spacecraft have been big enough to carry enough fuel to push for a few months - which more or less brought the craft up to the types of speeds we would see with a traditional rocket motor. However, bigger probes with bigger fuel tanks would be able to go quite a bit faster - if and when they get around to building such a spacecraft.
Eric Mc said:
Regarding ion drive, in theory the craft will keep accelerating as long as the ion motor keeps pushing. How long it can keep pushing is limited by the amount of fuel it can cary on board to feed the engine.
And its speed. IIRC mass increases as you reach c; IIRC to infinity. To accelerate infinte mass requires infinite power - one reason why you can't go faster than light. Or so my undergraduate brain recalls.Hooli said:
I didn't realise this probe had got so far. It's a bit of a milestone isn't it? The blokes who've worked on it for 40 odd years must be damn proud.
I like to think its still the same guys that launched it originally. All still beavering away in their old fashioned office.Amazing stuff tho.
Pioneers 10 nd 11 both launched in 1972 and encountered Jupter and Saturn in 1973/74.
According to heavens-above.com, five spacecraft are leaving the Solar System at this moment.
Pioneers 10 and 11
Voyagers 1 and 2
New Horizons
Here is the relevant data as of today -
The data, readiing from left to right, relates to Pioneer 10, Pioneer 11, Voyager 2, Voyager 1, New Horizons
Distance from Sun (AU) 107.023 86.721 99.937 122.289 24.702
Speed relative to Sun (km/s) 12.034 11.373 15.433 17.041 15.243
Speed relative to Sun (AU/year) 2.539 2.399 3.256 3.595 3.216
Ecliptic latitude 3° 14° -34° 35° 2°
Declination 25° 57' -8° 51' -55° 56' 12° 0' -21° 19'
Right ascension 5h 9m 18h 42m 19h 49m 17h 9m 18h 39m
Constellation Taurus Scutum Telescopium Ophiuchus Sagittarius
Distance from Earth (AU) 106.282 87.137 100.196 122.930 25.146
One-way light time (hours) 14.73 12.08 13.89 17.04 3.49
Brightness of Sun from spacecraft (mag) -16.6 -17.0 -16.7 -16.3 -19.7
Spacecraft still functioning? no no yes yes yes
Launch date 03/03/1972 06/04/1973 20/08/1977 05/09/1977 19/01/2006
One Astronomical Unit is roughly 93 million miles - the distance from the earth to the sun.
Voyager 2 is travelling fastest and as a result, has overhauled all the spacecraft launched before it.
According to heavens-above.com, five spacecraft are leaving the Solar System at this moment.
Pioneers 10 and 11
Voyagers 1 and 2
New Horizons
Here is the relevant data as of today -
The data, readiing from left to right, relates to Pioneer 10, Pioneer 11, Voyager 2, Voyager 1, New Horizons
Distance from Sun (AU) 107.023 86.721 99.937 122.289 24.702
Speed relative to Sun (km/s) 12.034 11.373 15.433 17.041 15.243
Speed relative to Sun (AU/year) 2.539 2.399 3.256 3.595 3.216
Ecliptic latitude 3° 14° -34° 35° 2°
Declination 25° 57' -8° 51' -55° 56' 12° 0' -21° 19'
Right ascension 5h 9m 18h 42m 19h 49m 17h 9m 18h 39m
Constellation Taurus Scutum Telescopium Ophiuchus Sagittarius
Distance from Earth (AU) 106.282 87.137 100.196 122.930 25.146
One-way light time (hours) 14.73 12.08 13.89 17.04 3.49
Brightness of Sun from spacecraft (mag) -16.6 -17.0 -16.7 -16.3 -19.7
Spacecraft still functioning? no no yes yes yes
Launch date 03/03/1972 06/04/1973 20/08/1977 05/09/1977 19/01/2006
One Astronomical Unit is roughly 93 million miles - the distance from the earth to the sun.
Voyager 2 is travelling fastest and as a result, has overhauled all the spacecraft launched before it.
Smiler. said:
Eric Mc said:
...
PS - the V1 was a crude form of pilotless jet aeroplane and had nothing really to do with rocket technology or spaceflight.
Thanks for clarifyingPS - the V1 was a crude form of pilotless jet aeroplane and had nothing really to do with rocket technology or spaceflight.
http://www.youtube.com/watch?v=jTsQxwWcqJI
Eric Mc said:
Smiler. said:
Eric Mc said:
...
PS - the V1 was a crude form of pilotless jet aeroplane and had nothing really to do with rocket technology or spaceflight.
Thanks for clarifyingPS - the V1 was a crude form of pilotless jet aeroplane and had nothing really to do with rocket technology or spaceflight.
http://www.youtube.com/watch?v=jTsQxwWcqJI
Sorry for any confusion.
Hooli said:
I didn't realise this probe had got so far. It's a bit of a milestone isn't it? The blokes who've worked on it for 40 odd years must be damn proud.
My thoughts exactly. Done with 40-50 years less technology too, it's truly staggering.I'm glad this thread has picked up, it's not really something you can talk about with the missus(well, mine anyway)!
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