[mikeash]

It should be noted that meteors explode with Hiroshima-like force fairly regularly within Earth's atmosphere, on the order of once a decade or so. It happens high up enough that nobody notices beyond an occasional light show. The meteor explosion which hurt a bunch of people in Chelyabinsk a few years back was about 500 kilotons.

[Stratoscope]

And so many of those people were injured because they went to a window to see the spectacle, not knowing about the shock wave that was coming.

It made me realize that the civil defense films we watched in the '50s weren't so misguided after all:

https://www.google.com/#q=when+you+see+the+white+flash+duck+...

[mikeash]

Indeed, that's pretty much what "duck and cover" was all about. There was even a school teacher in Chelyabinsk who apparently remembered her Cold War drills and had her students take cover, saving them from injury.

[dingbat]

cool, good to know that raining down a bunch of probes in this manner would most likely be a pretty light show. still i wonder about the plutonium aspect of this?

it might be prudent to first consult with the legal experts and diplomats of the Galactic Council, to clear this type of activity with them first, minimize interpretation of this probing as a hostile interstellar act.

[mikeash]

I don't think the plutonium would be enough to have any real effect, although it might irritate the inhabitants if there are any. Certainly, we've put far more plutonium into Earth's atmosphere by blowing up thousands of nuclear bombs in it, and we survived.

Clearing it with the Galactic Council definitely sounds like a good idea. Do you have their phone number handy? I seem to have deleted their contact info by accident.