This Hubble image captures a portion of a dark nebula in the constellation Cepheus. LDN 1165 is part of a collection called Lynds’ Catalog of Dark Nebulae, originally published in 1962. Dark nebulae – also called absorption nebulae – are clouds of gas and dust that neither emit nor reflect light, instead blocking light coming from behind them. These nebulae tend to contain large amounts of dust, which allows them to absorb visible light from stars or nebulae beyond them. Dark nebulae are so dark that they’ve been referred to as “holes in the sky,” but in reality they may be full of activity, with stars sometimes forming inside their dense clouds.