On January 9, 1848, Caroline Lucretia Herschel, German-British astronomer and sister of astronomer Sir William Herschel, passed away at age 98. She is best know for the discovery of several comets, in particular the periodic comet 35P/Herschel-Rigollet, which bears her name.
On June 26, 1730, French astronomer Charles Messier was born. He is best known for his publication of an astronomical catalogue consisting of nebulae and star clusters that came to be known as the 110 "Messier objects". The purpose of the catalogue was to help astronomical observers, in particular comet hunters such as himself, distinguish between permanent and transient visually diffuse objects in the sky.
On March 31, 1596, French philosopher, mathematician, and writer René Descartes was born. The Cartesian coordinate system is named after him, allowing reference to a point in space as a set of numbers, and allowing algebraic equations to be expressed as geometric shapes in a two-dimensional coordinate system. He is credited as the father of analytical geometry, the bridge between algebra and geometry, crucial to the discovery of infinitesimal calculus and analysis.
On November 8, 1656, Sir Edmund Halley was born, astronomer, geophysicist, mathematician, meteorologist, and physicist, best known for computing the orbit of the eponymous Halley's Comet.
On October 21, 2003, a photograph of the nocturnal sky was taken and revealed a possible 10th planet in our solar system: Eris. Unfortunately scientists came then to the conclusion that Eris and also Pluto could no longer hold the status as planets and were called dwarf planets from this point.
On October 2, 1608, German-Dutch lensmaker Hans Lippershey applied to the States-General of the Netherlands on October 2, 1608, for a patent for his instrument "for seeing things far away as if they were nearby".
On July 13, 1527, Welsh mathematician, astronomer, astrologer, occultist, navigator, imperialist and consultant to Queen Elizabeth I, John Dee was born. He is considered one of the most learned men of his age. Besides being an ardent promoter of mathematics and a respected astronomer, in his later years he immersed himself in the worlds of magic, astrology and Hermetic philosophy. One of his aims was attempting to commune with angels in order to learn the universal language of creation.
On October 17, 1604, the famous German astronomer Johannes Kepler started his observations of the 1604 supernova, named after him as Kepler's Supernova or Kepler's Star.
On February 19, 1473, Renaissance mathematician and astronomer Nikolaus Copernicus, who established the heliocentric model, which placed the Sun, rather than the Earth, at the center of the universe, was born.
On October 5, 1644 (or according to the old julian calendar September 25), Danish astronomer Ole Christensen Rømer was born. He is best known for making the first quantitative measurements of the speed of light.