Dutch astronomer Johannes Fabricius discovered sunspots.
Sunspots are regions of reduced surface temperature on the sun.
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Radiation from an explosion on the magnetar SGR 1806-20 reached Earth.
NASA's Mariner 6 space probe successfully launched from Cape Canaveral, Florida.
Two new moons of Saturn were found in photos from the Hubble Space Telescope by Astronomers Amanda S. Bosh and Andrew S. Rivkin.
The Japanese Space Agency sent two robots to explore an asteroid aboard their Hayabusa-2 spacecraft.
Kepler's Supernova was discovered.