What caused Voyager 2 to send back garbled information? Was it aliens?

"Did they ever find out what caused Voyager 2 to start sending back garbled information? Was it interfered with by aliens?"

Question posed by A. Nonymous

By NASA, via Wikimedia Commons

Voyager 2 has been sending information about our solar system back to Earth since its launch in 1977, but back in April of this year (2010, in case you're reading this in the future) it suddenly started sending data that was completely unintelligible to the scientists back home. Hartwig Hausdorf, a German academic, suggested that the change could be due to extra-terrestrials who were trying to send us a message, but NASA engineers working at JPL found the problem to be caused by a software bug: just one memory bit in the computer that is responsible for formatting the data before it is sent has flipped from a zero to a one.

So a software bug caused the data to be garbled, not aliens. Although we don't know what caused the bug to make itself apparent at that particular time...*

• More information about the issue can be read here.
• You can read a bit more about the Voyager probes in this post.

* Yes, I am attempting to be slightly conspiratorial in my tone, but no, I don't believe it was triggered in some way by aliens. I'm just doing it for effect!