Rogue planets are planets without a host planetary system and thus roam freely in space. Without sunlight, could life exist via oceans prevalent underneath a thick layer of ice? With so many rogue planets, is this where we should be searching?
Link: https://phys.org/news/2021-09-planets-rogue-sustain-life.html

Astrobiology
Charting the Cosmos: the Concept of Kardashev Civilizations
As we gaze upon the universe, contemplating our place in its vast expanse, we grapple with questions about our future.