Are the Stars You See Already Dead? The Truth Hidden in Starlight

Could a star die while its earlier light is still traveling toward Earth? Yes—but old starlight does not mean the night sky is filled with vanished stars. Follow the journey from moonlight and sunlight to distant stellar explosions. Discover how astronomers measure stellar distances, why massive stars live shorter lives, and how a white dwarf can keep shining after its main source of nuclear energy is gone. Through Betelgeuse’s Great Dimming, Supernova 1987A, neutrinos, and light echoes, explore how scientists separate what they observe from what they can only predict. Then travel beyond the familiar stars to Andromeda, the expanding universe, and the cosmic microwave background—and discover why looking into space also means looking into the past.