tl;dr: Astroterm is a lightweight C-based terminal planetarium that renders real-time positions of stars, planets, constellations, and moon phases in ASCII. Users can customize views by date, time, and location (via coordinates or city name), making it possible to visualize past, present, or future night skies. It's available via package managers like pacman, dnf, and Homebrew, or as prebuilt binaries for Linux, macOS, and Windows.