They damned well better hope there isn’t intelligent life out there.
Kamikaze Starshot: Will Some Interstellar Probes Slam into Their Target Planets?
The baseline plan calls for the robotic nanocraft to hunt for signs of life and gather other data during flybys of nearby alien worlds such as Proxima b, a potentially habitable planet located just 4.2 light-years from Earth. But the scientific return would be even greater if some of the 1-gram probes actually slammed into their target worlds, some researchers said.
University of Hawaii physicist Jeff Kuhn said the explosion would be even more powerful; during a different Breakthrough Discuss panel on April 21, he estimated the yield at perhaps 100 kilotons. For comparison, the atomic bomb that the United States dropped on the Japanese city of Hiroshima toward the end of World War II had an explosive yield of about 15 kilotons.
I’ll have to look up the math later. 1 kiloton seems low, but 100 kilotons seems pretty high. (If both seem insanely high, remember that this isn’t a straight “muzzle energy” Newtonian calculation; at 20% light speed relativistic effects come into play.)
In the unlikely event we have some neighbors around Proxima, these guys might want to stop and consider how we would feel about someone else detonating multiple “nuke” airbursts here. Imagine ten simultaneous Chelyabinsk events.