Edward Walter Maunder (April 12, 1851 РMarch 21, 1928) was an English astronomer best remembered for his study of sunspots and the solar magnetic cycle that led to his identification of the period from 1645 to 1715 that is now known as the Maunder Minimum. April 12 is the 102nd day of the year in the Gregorian calendar (103rd in leap years). ... Events January 23 - The flip of a coin determines whether a new city in Oregon is named after Boston, Massachusetts, or Portland, Maine, with Portland winning. ... March 21 is the 80th day of the year in the Gregorian Calendar (81st in leap years). ... 1928 was a leap year starting on Sunday (link will take you to calendar). ... An astronomer or astrophysicist is a scientist whose area of research is astronomy or astrophysics. ... 400 year sunspot history A sunspot is a region on the Suns surface (photosphere) that is marked by a lower temperature than its surroundings, and intense magnetic activity. ... // Events January 10 - Archbishop Laud executed on Tower Hill. ... // Events September 1 - King Louis XIV of France dies after a reign of 72 years, leaving the throne of his exhausted and indebted country to his great-grandson Louis XV. Regent for the new, five years old monarch is Philippe dOrl̩ans, nephew of Louis XIV. September - First of... The Maunder minimum in a 400 year history of sunspot numbers The Maunder Minimum is the name given to the period roughly from 1645 to 1715 A.D., when sunspots became exceedingly rare, as noted by solar observers of the time. ...

After working at the Royal Greenwich Observatory he graduated from King's College, London before taking a job in a London bank. In 1873 he returned to the Royal Observatory, taking a position as a spectroscopic assistant. Part of his job involved photographing and measuring sunspots, and in doing so he observed that the solar latitudes at which sunspots occur varies in a regular way over the course of the 11 year cycle. After 1891, he was assisted in his work by his second wife, Annie Scott Dill Maunder (neé Russell), a mathematician educated at Cambridge University. Royal Observatory, Greenwich The original site of the Royal Greenwich Observatory (RGO), which was built as a workplace for the Astronomer Royal, was on a hill in Greenwich Park in Greenwich, London, overlooking the River Thames. ... Kings College London (often abbreviated to KCL) in London is one of the largest colleges in the federal University of London, with 19,500 registered students. ... 1873 was a common year starting on Wednesday (see link for calendar). ... Spectroscopy is the study of spectra, that is, the dependence of physical quantities on frequency. ... A sun is the star at the center of a planetary system. ... 1891 was a common year starting on Thursday (see link for calendar). ... Edward Walter Maunder (April 12, 1851 – March 21, 1928) was an English astronomer best remembered for his study of sunspots and the solar magnetic cycle that led to his identification of the period from 1645 to 1715 that is now known as the Maunder Minimum. ... A mathematician is a person whose area of study and research is mathematics. ... The University of Cambridge is the second-oldest university in the English-speaking world (after Oxford). ...

After studying the work of Gustav Spoerer, who had identified a period from 1400 to 1510 when sunspots had been rare ("the Spoerer Minimum"), he examined old records from the observatory's archives to determine whether there were other such periods. These studies led him in 1893 to announce the period that now bears his name. Friederich Wilhelm Gustav Spörer (October 23, 1822 – July 7, 1895) was a German astronomer. ... Events Henry IV quells baron rebellion and executes The Earls of Kent, Huntingdon and Salisbury for their attempt to have Richard II of England restored as King Jean Froissart writes the Chronicles Medici family becomes powerful in Florence, Italy Births Owen Tudor, seventh generation descedant of Rhys ap Gruffydd (approximate... Events Conquest of Pskov by Grand Prince Vasili III of Muscovy. ... The Spörer Minimum was a period of low solar activity which lasted from about 1420 to 1570 (some say 1450 to 1550). ... 1893 was a common year starting on Sunday (see link for calendar). ... The Maunder minimum in a 400 year history of sunspot numbers The Maunder Minimum is the name given to the period roughly from 1645 to 1715 A.D., when sunspots became exceedingly rare, as noted by solar observers of the time. ...

He observed Mars and was a skeptic of the notion of Martian canals. He conducted visual experiments using marked circular disks which led him to conclude, correctly, that the viewing of canals arose as an optical illusion. A crater on Mars was named in his honor. Mars is the fourth planet from the Sun in the solar system, named after the Roman god of war (the counterpart of the Greek Ares), on account of its blood red color as viewed in the night sky. ... For a time in the late 19th and early 20th centuries, it was believed that there were canals on Mars. ... An optical illusion is any illusion that deceives the human visual system into perceiving something that is not present or incorrectly perceiving what is present. ... This article is about impact craters, also known as meteor craters. ...

External links

• J. E. Evans and E. W. Maunder, "Experiments as to the Actuality of the 'Canals' observed on Mars", MNRAS, 63 (1903) 488