In this month: January
7 January 1610
Galileo discovers four moons orbiting the planet Jupiter. Looking at what he thought were a group of stars, he noted the objects appeared to move in a regular pattern and realised they were in orbit around Jupiter. Today, Jupiter’s four largest satellites—Io, Europa, Ganymede, and Callisto—are named the Galilean Moons in honour of their discoverer. They were the first objects found to orbit another planet. His discoveries would lead to the development of modern astronomy and provided evidence for the Copernican understanding of the universe, the idea that everything in existence did not move around the Earth.
26 January 1946
Ruby Payne-Scott carries out the first use of a radio interferometer for astronomical observation using an Australian Army radar antenna as a radio telescope at Dover Heights, Sydney. She continued these ground breaking activities until 1951. The image below shows Ruby Payne-Scott with Alec Little and "Chris" Christiansen at the Potts Hill Reservoir Division of Radiophysics field station in about 1948. Payne-Scott and Little were working on observations of the Sun at 97 MHz using the newly constructed swept-lobe interferometer. ATNF Historical Photographic Archive - B14315. courtesy Jessica Chapman [CC BY 3.0 (https://creativecommons.org/licenses/by/3.0)]
31 January 1961
As part of the USA space program to see if humans could function in space a chimpanzee, Ham, is launched into space. His flight lasted 16 mins and 39 seconds. During the flight he was required to push a lever within five seconds of seeing a flashing blue light which proved that tasks could be completed in space. Ham's name is an acronym for the laboratory that prepared him for his mission—the Holloman Aerospace Medical Centre, located in New Mexico, USA. After the flight he lived the rest of his life in various zoos in the USA and died in 1983.
19 January 1747
Johann Elert Bode. German astronomer. Best known for discovering a numerical series that predicted the distances of the planets from the Sun, now known as Bode’s Law in his honour. Bode also determined the orbit of Uranus and suggested the planet's name. He was a member of the Royal Society of London, as well as of the academies of Berlin, St. Petersburg, Stockholm, Copenhagen, and Göttingen.
23 January 1941
Beatrice Muriel Hill Tinsley. British-born New Zealand astronomer and cosmologist. Her research made fundamental contributions to the astronomical understanding of galaxies and she became the world’s leading expert on the aging and evolution of galaxies. In 1978, she became the first female professor of astronomy at Yale University. She died at the relatively young age of 40. Her last scientific paper was published posthumously without revision. The Copyright owner for the image below was unable to be found.
8 January 1942
Stephen Hawking English theoretical physicist, cosmologist, and author. Known for his complex work on black holes. He was Lucasian Professor of Mathematics at the University of Cambridge between 1979 and 2009. In 1963, Hawking was diagnosed with motor neurone disease that gradually paralysed him over the decades. During his career he received over a dozen honorary degrees and was awarded the CBE in 1982. He is regarded as one of the most brilliant theoretical physicists since Einstein.