Comment Duhh! Deflation (Score 1) 272
The obvious answer is that Voyager 1 punctured the helioshpere as it passed through. It (helioshpere) has been deflating ever since (much like a balloon with a slow leak).
Just be thankful that it did not pop in a violent manner like most fully inflated balloons do when punctured.
Now, do we have any volunteers to travel to the location of the hole with a patch and some rubber cement?
