NHAS - Today in Astronomy History

	1642	Italian astronomer, philosopher and mathematician Galileo Galilei dies. He improved upon the refracting telescope and was one of the first to use it to study the heavens. He discovered mountains and valleys on the moon, the four larger moons of Jupiter, sunspots, and the phases of Venus and Mercury. His discoveries provided crucial evidence for the Copernican theory that the Earth orbits the Sun and not vice versa. His support for this theory landed him in a trial before the Spanish Inquisition in 1633.
	1942	British astrophysicist and cosmologist Stephen Hawking born. He devised a new area of mathematics to describe the behavior of black holes under general relativity. By combining these principles with quantum theory, he showed that black holes emit radiation, now called Hawking Radiation. His later work includes the "No Boundary Proposal," which predicts that space and time are finite in extent, but without any boundary or edge.
	1952	American astronomer Antonia C. Maury dies. She worked on the classification of stellar spectra at Harvard Observatory as early as 1890. She was the first to discover the spectroscopic differences in stars now known as giants, supergiants and dwarfs.