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Thanks for these graphs! Your Voyager 1 graph [footnote 0, in the parent comment] shows two periods of particles-per-second drops to around 10 particles per se

Thanks for these graphs! Your Voyager 1 graph [footnote 0, in the parent comment] shows two periods of particles-per-second drops to around 10 particles per second followed by a rebound and then a dramatic drop to 2 to 3 particles per second. The Voyager 2 graph [footnote 2, in the parent comment] shows a single drop to around 17 to 18 particles per second and what looks like the beginning of a rebound. Wouldn't interstellar space be characterized by the drop to below 3 particles per second? Is this the same issue we had with Voyager 1 where Voyager 2 is beginning the process of entering interstellar space but has not yet actually entered it? If not, why are the particle counts about an order-of-magnitude higher for Voyager 2 then they were for Voyager 1 in interstellar space?

21 8y ago
> why are the particle counts about an order-of-magnitude higher for Voyager 2 then they were for Voyager 1 in interstellar space Better detector? Those are detected particle counts
- rohansingh 8y ago
  Voyager 2 was launched a couple weeks before Voyager 1. They are pretty much the same.
jmts 8y ago
My first reaction when I saw this - probably a reaction due to previous repeated news about Voyager 1 leaving - was "But hasn't it already left, multiple times?". This is explained somewhat in GP's footnote [3]: In early November, the team noticed a sharp decline in the number of particles, but not to zero. This means that the spacecraft still has a long way to go until scientists can declare it free from the solar system. Due to the fact that the power of the Sun rises and decreases, the position of the heliopause is not constant. Therefore, it is impossible to say exactly when Voyager 2 will leave the Solar System. So your interpretation is correct, Voyager 2 is approaching the boundary, but hasn't yet definitively crossed into interstellar space. The phrase 'leaves the Solar System' is misleading, depending on your interpretation of where it ends. We can probably expect a few more confused articles announcing this in the next few months until it is certain. [3] http://earth-chronicles.com/space/voyager-2-is-even-closer-to-the-border-of-the-solar-system.html http://earth-chronicles.com/space/voyager-2-is-even-closer-t...

21 8y ago

> why are the particle counts about an order-of-magnitude higher for Voyager 2 then they were for Voyager 1 in interstellar space Better detector? Those are detected particle counts

rohansingh 8y ago
Voyager 2 was launched a couple weeks before Voyager 1. They are pretty much the same.

jmts 8y ago

My first reaction when I saw this - probably a reaction due to previous repeated news about Voyager 1 leaving - was "But hasn't it already left, multiple times?". This is explained somewhat in GP's footnote [3]: In early November, the team noticed a sharp decline in the number of particles, but not to zero. This means that the spacecraft still has a long way to go until scientists can declare it free from the solar system. Due to the fact that the power of the Sun rises and decreases, the position of the heliopause is not constant. Therefore, it is impossible to say exactly when Voyager 2 will leave the Solar System. So your interpretation is correct, Voyager 2 is approaching the boundary, but hasn't yet definitively crossed into interstellar space. The phrase 'leaves the Solar System' is misleading, depending on your interpretation of where it ends. We can probably expect a few more confused articles announcing this in the next few months until it is certain. [3] http://earth-chronicles.com/space/voyager-2-is-even-closer-to-the-border-of-the-solar-system.html http://earth-chronicles.com/space/voyager-2-is-even-closer-t...