On this Day in History

On this Day in History in 295: 8th recorded perihelion passage of Halley’s Comet.
On this Day in History in 1702: Comet C/1702 H1 approaches within 0.0437 AUs of Earth.
On this Day in History in 1902: Marie & Pierre Curie isolate the radioactive element radium chloride.
On this Day in History in 1940: The First electron microscope was demonstrated by RCA.

Fun Fact of the Day

Fun Fact of the Day: Gamma rays are the most energetic type of light, packing a punch strong enough to pierce through metal or concrete barriers. More energetic than X-rays, they are born in the chaos of exploding stars, the annihilation of electrons and the decay of radioactive atoms.