"Journey to the Microcosmos: Diatoms--Tiny Factories You Can See From Space" explores diatoms, photosynthetic unicellular algae found in water-filled environments. The video explains how these microscopic organisms were first described in 1703, examines their glass-like silica shells called frustules, and shows how their cell division, sexual reproduction, and limited motility work. It also highlights key life science concepts including photosynthesis, cytoplasm, algae, microscopy, and the role of actin in movement. The video connects diatoms to Earth systems by noting their major contribution to global oxygen production, ocean blooms visible from space, and the formation of diatomaceous earth. It also introduces biotechnology applications, including research into biofuels. This content aligns strongly with biology, microbiology, ecology, and scientific observation in school science curricula. Part of the "Journey to the Microcosmos" series.