In this chthonian world the only thing of importance is orthography and punctuation . It doesn 't matter what the nature of the calamity is , only whether it is spelled right .
Sometimes hot jupiters or hot neptunes live too close to their stars for comfort . Once their stars roast these exoplanets and rip at them with their gravity , they might blow the gas completely off them , leaving behind rocky cores scientists have dubbed chthonian planets or evaporated remnant cores .