Astro Anniversaries

July

Day	Year	Event
1	1916	Iosif Shklovsky born. A great Soviet theoretical astrophysicist. His work identified the mechanisms that produce radio waves from the sun and many sources in our galaxy.
2	1906	Hans Bethe born. He was a German physicist who developed the details of how nuclear reactions power the sun. That work won him the Nobel prize for physics in 1967.
4	1868	Henrietta Leavitt born. An American astronomer. She discovered the Period-Luminosity relationship for Cepheid variable stars, which opened up our understanding of the distances of objects in the universe.
5	1687	The first edition of Isaac Newton’s Principia Mathematica was published, setting out for the first time the laws that govern motion on Earth and in the heavens.
6	1995	Michel Mayor and Didier Queloz, working at the Observatoire de Haute-Provence, were finally able to firm up their data and thus claim the discovery of 51 Pegasi b, the first planet found around an ordinary star other than the Sun. Subsequently, they received the Nobel Prize in Physics for their work in 2019.
7	1950	Yuji Hyakutake born. He was a Japanese amateur astronomer who discovered the splendid Comet C/1996 B2, also known as Comet Hyakutake, on January 31, 1996, while using 25×150 binoculars to look for C/1995 Y1, a comet he had discovered a few weeks before.
8	1695	Christiaan Huygens died. He was a pioneering physicist and astronomer, born in the Hague in the Netherlands. Huygens went on to discover Saturn’s largest moon and characterise its ring system, invent the pendulum clock and suggest the equation for centripetal force, amongst many other contributions to science.
11	1909	Simon Newcomb died. Newcomb was a Canadian-born American astronomer and mathematician who prepared ephemerides (tables of computed places of celestial bodies over a period of time) and tables of astronomical constants.
14	1965	The Mariner 4 spacecraft flew by Mars and sent back the first close-up images of another planet from space. It showed a cratered landscape and no canals or other evidence of martians!
14	2015	The New Horizons spacecraft flew by Pluto, just 12,000 km from its surface, returning the first images of – and data from – that distant dwarf planet.
16	1746	Giuseppi Piazzi born. An Italian astronomer, Piazzi discovered the first asteroid.
16	1850	The first photograph was taken of a star (Vega) other than the sun by William Bond and John Adams Whipple at the Harvard College Observatory.
16	1994	The first fragment of Comet Shoemaker-Levy 9 collided with Jupiter, an event that greatly expanded public awareness of planetary impacts in the solar system.
17	1894	Georges LeMaitre,born .An astrophysicist and Catholic Priest, LeMaitre interpreted Edwin Hubble’s findings about the expanding universe to mean that the cosmos must have had an origin, and thus LeMaitre became one of the originators of the Big Bang Theory.
18	1997	Eugene Shoemaker died. Shoemaker was an American geologist who co-discovered Comet Shoemaker–Levy 9 with his wife Carolyn Shoemaker and colleague David Levy. This comet hit Jupiter in July 1994and the impact was televised around the world.
20	1960	Neil Armstrong and Edwin “Buzz” Aldrin landed on the Moon as part of the US Apollo 11 mission, and thus became the first humans to set foot on another world.
21	1976	The Viking 1 lander on Mars sent back the first colour image from the surface of another planet, just one day after its landing.
23	1928	Vera Rubin born. An American astronomer, Rubin became one of the key discoverers of dark matter in the universe and a path-breaker for women in astronomy.
27	1801	George Biddell Airy born. An British mathematician and astronomer, and the seventh Astronomer Royal from 1835 to 1881.
28	1851	Johann Berkowski took the first image of the sun’s corona during a total eclipse in 1851 at the Konigsberg Observatory in Prussia.

LAST UPDATED: 2024-07-03