Interstellar Clouds And Dark Nebulae

Picked one by one from a mixed channel. Transcript check: both title readers certain; 5 of 5 sampled certain picks confirmed by transcript, none failed. Channel rule: Include only narrated explainer episodes of 3 minutes or more where a host or scientist teaches the science (Hubble's Universe Unfiltered, Hidden Universe, ESOcast, International Year of Astronomy object features, ESA mission-results features). Exclude APOD weekly slideshows, music-only visualizations, mission advocacy pieces, sub-3-minute news blurbs and hype-titled flyovers.