Supermassive black holes can render exoplanets uninhabitable at great distances

The thinking around exoplanet habitability is mostly concerned with a planet's distance from its star. Too close, and any surface water is boiled away into space. Too far, and surface water is frozen. Both are severe limits on the prospects for life. Habitability depends on an exoplanet being in the Goldilocks Zone, a distance range around a star where liquid water can persist.