July 2008, a new limit reached!

I heard of Voyager 2 and the fact that it was still functional: 30 years after it left Earth! Just that is amazing to me.

The craft went through the termination shock several times now (5 if I’m correct). This is far. Further away from the Sun than Pluto. And Pluto is on average around 39.5 AU from the Sun. It is even further than Eris and Eris lies at about 67 AU on average.

Now, July 2008, we finally got enough data from Voyager 2 to know what is happening at the termination shock. It is what I would call the first edge of the Solar system. Some 84 AU but really it changes all the time, which explains why Voyager 2 already went in and out several times. That place is where the Solar wind slow down from 350 km/s to only 130 km/s. Solar winds are formed of atoms that are ejected by the Sun and travel very, very far. This forms a bubble inside which the planets reside. In some respect, it is protective, in others, it is quite destructive. On Earth, we are protected because of the Earth magnetic field (our atmosphere protects us from some light waves, not the Solar wind.)

And now we have finally recorded measurements of the amount of particles that reside at the edge. The results are quite different from what was expected…

And, I thought it was quite interesting to read that all the theories used a couple months ago where no good to explain what really happens at the edge of any star bubble. With that in mind, how can we really tell about anything beyond our solar system?

This brings me to a good analogy in software development. You write thousands and thousands of lines of code and it looks like it works great. You start selling your product and once in a while, a customer tells you that it does not work for them. And you have no clue why it fails on that customer computer…

So… our theory was: it works for me, therefore the code is working, ready for sale and it will work on all computers since they are all alike. The truth is: there is still at least one bug, and really very likely more.

Anyhow, I hope we’ll learn a lot more about the outside of the solar system as Voyager 1 & 2 continue their journey.