A newly discovered, faint radio emission, the Hectometric Continuum, emerges only after sunset and pulses through Earth’s upper atmosphere for several hours. This natural radiation, undetectable from the ground, originates from plasma interactions within the magnetosphere and has surprised scientists due to its nighttime-only appearance and sensitivity to calm space weather.
3I/ATLAS becomes the UN’s official target in a planetary-defence exercise: What makes this interstellar visitor worth a global campaign
Interstellar comet 3I/ATLAS is the focus of the eighth official UN and IAWN planetary-defence exercise, running from November 27, 2025, to January 27, 2026. This live, coordinated global campaign allows…
