O tema "lutando contra a guerra dos alienígenas" vem na série Rank of Bronze por Weber et al., e outros livros também. Um tema similar com os terráqueos lutando contra alienígenas de nível tecnológico muito diferente - desta vez, acidentalmente - é A Alta Cruzada por Poul Anderson (e uma abordagem ainda diferente sobre o tema, com ainda mais acidentalidade , é o O caminho não levado ).
Mas a partir do míssil planetário disparado contra o núcleo da Terra, esta é provavelmente a Série Galactic Empire Wars (especificamente volume 1: Destruction ) por Raymond L. Weil. Aqueles na capa são os ternos mecha.
Esta é a sinopse da Amazon, que corresponde à sua lembrança (ênfase minha):
To the Kleese, the Earth is nothing more than a planet full of conscripts to fight in their wars of aggression against other planets. The Kleese are one of three large Galactic Empires that control the majority of the galaxy. To them, Earth is a dangerous planet due to the aggressiveness of the humanoid species that inhabits it. This is a species that cannot be allowed to go out into the galaxy. Once they have taken their conscripts, the planet will be destroyed.
Mason Randle controls the Smithfield Mining Corporation. His main base is inside the asteroid Vesta, and he will do everything in his power to save what is left of the human race after the Kleese attack.
Esta é a cena em que o míssil planetkiller atinge. Se bem me lembro, os Kleese tinham conhecido Luna City e as colônias de asteróides, mas acreditavam que não seriam capazes de sobreviver sem a Terra para reabastecimento.
“The aliens have launched what appears to be a missile toward Earth,” Darren replied in a strained voice. “We’re tracking it, and it will impact the planet in six minutes.”
[...] On the screen, Luna City had now turned from tracking the alien ship to tracking the inbound missile that was targeting the Earth. [...] “Impact,” Darren spoke over the com, sounding confused. “We’re not seeing or recording any type of detonation.” [...] “I don’t like this,” spoke Drake, clenching and unclenching his fist as he continued to watch the screen, which was now focused on South America. “We’re missing something. There has to be a reason why the alien ship launched that missile, and I can’t believe that it malfunctioned.”
(o míssil ainda não tinha detonado. Ainda estava cavando em direção ao núcleo).