Well, my problem is, I’ve got this race of exceedingly nasty alien creatures which I now need to get rid of. (The story is set in the present day.)
Basically, these aliens made an evolutionary breakthrough that made them far too good at predation. They wiped out almost all land animals on their planet, and thus had to look further afield for food. And, as we all know from science-fiction, all malevolent alien forces will inevitably come across and consequently target Earth. This is probably some postulate and/or corollary of Murphy’s Law.
So some of the aliens came to Earth and ate a few people, thus driving most of the events of the plot. But now they’ve fulfilled their role, and I need to get rid of them for a nice climax. I could just come up with something and say it’s so, but I much prefer to be as scientific and realistic as possible.
Here’s the situation: The majority of the aliens are still on their home planet, which is approximately the same density as Earth and has a very similar atmosphere, but is a bit larger. There is a (very fragile) wormhole-type link between this planet and Earth, which will not be able to withstand the passage of matter. (So nuclear missiles are out.) I have massive amounts of energy at my disposal, and a way of getting it through the wormhole. Oh, and Earth’s general population (including the governments) have no idea what’s going on.
My question is, what form of energy would be most effective at wiping out the dominant species of a planet, and how much energy would be required? (Just to be clear, spreading disease isn’t an option of extermination here.) I would like the planet to remain habitable, preferably maintaining plant life, but this isn’t necessary.
I have tried to research this, but the best I’ve found is some vague speculation on the effects a large solar flare would have on the Earth. Any ideas would be appreciated!