Voyager's On-ramp to Interstellar Space

[Deano]

After 35 years in space, NASA's long-distance interplanetary probe finds itself on the cusp of leaving the Sun's magnetospheric bubble.
Today, 35 years later, Voyager 1 is 11.3 billion miles from home and Voyager 2 is 9.3 billion away, respectively 122 and 100 times the Earth-Sun distance. Surprisingly, both are still inside the heliosphere — but apparently not for long. As Stone and his colleagues described at a NASA briefing yesterday, Voyager 1 has entered a new and unexpected realm that puts it on the doorstep of passing into interstellar space.
But on July 28th, the spacecraft caught its handlers flat-footed by reporting a sudden drop in the count of solar-wind particles and a corresponding surge of low-energy cosmic rays streaming in from the great beyond. That lasted five days. Then another week-long episode followed beginning on August 13th, and by August 25th the rapid two-way flow had become the new normal. "Things have changed dramatically," admits Krimigis. "The [solar-wind] particles are a thousand times less than what we had before. We can hardly measure them."
Full story & pics
http://www.skyandtelescope.com/community/skyblog/newsblog/Voyager-1-Hits-On-ramp-to-Interstellar-Space-182012171.html

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[Suezy]

Very interesting and thanks Deano.  Will be interesting to see what happens next.

[Deano]

Voyager 1: Is It In or Is It Out?

Nearly 18.7 billion kilometers from Earth — about 17 light-hours away — NASA’s Voyager 1 spacecraft is just about on the verge of entering interstellar space, a wild and unexplored territory of high-energy cosmic particles into which no human-made object has ever ventured. Launched in September 1977, Voyager 1 will soon become the first spacecraft to officially leave the Solar System.

Or has it already left?

I won’t pretend I haven’t heard it before: Voyager 1 has left the Solar System! Usually followed soon after by: um, no it hasn’t. And while it might all seem like an awful lot of flip-flopping by supposedly-respectable scientists, the reality is there’s not a clear boundary that defines the outer limits of our Solar System. It’s not as simple as Voyager rolling over a certain mileage, cruising past a planetary orbit, or breaking through some kind of discernible forcefield with a satisfying “pop.” (Although that would be cool.)

According to Swisdak, fellow UMD plasma physicist James F. Drake, and Merav Opher of Boston University, their model of the outer edge of the Solar System  fits recent Voyager 1 observations — both expected and unexpected. In fact, the UMD-led team says that Voyager passed the outer boundary of the Sun’s magnetic influence, aka the heliopause… last year.

Full story at Universe Today