December 25
1741 – The Centigrade temperature scale was devised by astronomer Anders Celsius.
1758 – Halley's Comet is sighted by Johann Georg Palitzsch, confirming Edmund Halley's prediction of its passage. (This was the first passage of a comet predicted ahead of time.)
1906 – Engineer Ernst Ruska is born, best known for inventing the electron microscope.
1942 – Physicist Sir Isaac Newton is born. This well-known scientist made seminal discoveries in several areas of science, and was the leading scientist of his era. The statement of his three laws of motion are fundamental in the study of mechanics.
1945 – Star Trek producer Rick Berman is born.
1968 – Apollo 8 performs the very first successful "Trans Earth Injection" (TEI) maneuver, which sends the crew and spacecraft on a trajectory back to Earth from Lunar orbit.
2021 – The James Webb Space Telescope is launched, sent on a mission to accomplish four things:
