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Comment by richeyrw | Hacker News Reader

Phil Plait of Bad Astronomy has come down on the "this time it's for real" side of things. The graph he shows seems pretty convincing:

http://www.slate.com/blogs/bad_astronomy/2013/03/20/voyager_...

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Really?

>[Update/Correction (Mar. 19, 2013): I wrote the piece below after reading a press release from the American Geophysical Union (AGU) and after reading the professional science journal paper announcing the results. Just after posting this I received a press release from NASA/JPL quoting Ed Stone, the Voyager project scienist, saying "It is the consensus of the Voyager science team that Voyager 1 has not yet left the solar system or reached interstellar space.... [Emphasis mine.] I then received a follow-up press release from the AGU also backing off the claim of Voyager leaving the solar system.... So to be clear, the science of what I describe below is accurate enough, but the idea that Voyager 1 has left the building is not.

My guess, is that Voyager being declared "outside" the solar system will happen only after quite of bit of time has passed since it actually left. Like the Higgs Boson, there is data, there is analysis, and there are confidence intervals. One result may be that the instruments send back cosmic ray information that no theory can explain how that would be consistent with being inside the heliosphere. Or it may simply be that the environment stops changing. And after a while that non-changing result is accepted as being "outside" and then you can walk backwards in the data to figure out the first time you got that result (and consequently the last change you saw) and declare the exit that way.

They called in the big guns. Here's the correcting press release:

http://www.jpl.nasa.gov/news/news.php?release=2013-107

Ed Stone, the project scientist and the nominal author of this press release, is 77 now. He was 41 when Voyager 1 launched (and he was project scientist then, too). You still see him around JPL and Caltech.

So it's out of the solar system - but is it in interstellar space?

Reading the Bad Astronomy blog entry got me thinking about the Oort Cloud - perhaps that is the real interstellar space (within the galactic plane) - beyond the Bow Shock and at a size of 1.5-3.0 LY with a spherical distribution, the cloud edge is closer to some of our nearest stars (notably Alpha Centauri, whose binary mass is 2 solar masses) than to the sun.

Perhaps the Oort Cloud is interestellar space - in which case, V1 hasn't gotten there yet.

Are you saying that our Oort Cloud potentially intersects with Oort Clouds of other stars? I didn't realize it was that big. Maybe interstellar space is ALL Oort Cloud, and we just haven't noticed because the masses are too small and cold to see (and obscured by closer stuff.) Maybe that's enough to make up the dark matter mass?

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