The Diaspora — R.C. Miller

“Optimally, the flare is twice as long, or more, than the distance to the target. This ensures that the target suffers the full power of the flare. The first effect of the flare will be an enormous EMP �" electromagnetic pulse �" that will destroy all electronic devices that have any kind of power still in them, stopping any way of getting out of the flare's path, or shielding any part of the target. Even starships are not able to shield from an EMP of this size. And even if they could, the heat would still be like skimming the surface of the sun.“The planet's surface is immediately burned up by the flare's heat. All the water down to two full kilometers underground will flash to steam in a millimin, causing a huge amount of pressure for an instant. That rush of pressure will carry almost all of the planet's air out into space. “What life on the planet that may not be burned will be squeezed by the pressure and then boiled by the super-heated steam. If anything could possibly live through that sequence, the vacuum left by the atmosphere being blown into space, along with what air might possibly remain being filled with water vapor and ash, will complete the goal of wiping out all life on that planet. The ash cloud will be so thick that no light will get through it, leaving the planet a bare and frozen rock. Nothing living could possibly survive for even a decamin under such conditions!”