> I suspect the size of the particles and number is very very low
The number is indeed low, though the size can be anything from a molecule to full-sized planet.
On the other hand, 16 million years is a very very long time, and 17 km/s (the current velocity of Voyager 2) is a respectable velocity.
Even small particles will take the "new" right off something at that velocity. By comparison, the velocity of a 5.56 mm rifle bullet is only about 1 km/s.
The number is indeed low, though the size can be anything from a molecule to full-sized planet.
On the other hand, 16 million years is a very very long time, and 17 km/s (the current velocity of Voyager 2) is a respectable velocity.
Even small particles will take the "new" right off something at that velocity. By comparison, the velocity of a 5.56 mm rifle bullet is only about 1 km/s.