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.

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.

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.

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.

External links

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