Any civilization capable of sending missiles across the galaxy should be more than capable of simply sending a tight beam of gamma radiation to sterilize the planet. No need for earth shattering explosions. Just a flood of radiation engulfing the planet for a minute or two and everything not buried a mile underground will be dead. There would be no warning either.
And that’s if they don’t bother to just blow up the sun.
They’ve already sent galactic missiles to wipe us out before we can ruin them.
Any civilization capable of sending missiles across the galaxy should be more than capable of simply sending a tight beam of gamma radiation to sterilize the planet. No need for earth shattering explosions. Just a flood of radiation engulfing the planet for a minute or two and everything not buried a mile underground will be dead. There would be no warning either.
And that’s if they don’t bother to just blow up the sun.