First specail when Aliens attack. Why Aliens attack total none sense. They get lot jet fighter shoot back at them. Going attack orbit at least first if they want shock aw effect let everyone see first hand allow sattilites militery get crushed. See ourself defese less or going just bombing space going to drop combat robots bring fear destroy industrusm they hit from space likley laser to. Also they watch did hit run operation they going to send drones after way smell easily hit rife or anythng else.
Alos Evaltion Earth beside fact forget the option simple moving Earth every if something was happen. Specail case Neturan Star. Of course using object big astriond or lot more of them. Of even plan artifcal gravity move astriond so part astriond defense plan it very possible turn that option.
THen of course the starship design anti matter to dangers. Well saver then 80 year voyage to the nearest Earth like planet. Tons things in just deep space could kill what hiberation techology no talk race against time design and having that working in 70 years. Pratice terms all likehood able pull next few decades anyway just something not poison that act from anti freeze coming water body full body well that and we set.