Chapman Medal

The Chapman Medal is an award of the Royal Astronomical Society, given for "investigations of outstanding merit in the science of the Sun, space and planetary environments or solar-terrestrial physics". It is named after Sydney Chapman (1888–1970), a British geophysicist who worked on solar-terrestrial physics and aeronomy. The medal was first awarded in 1973, initially on a triennial basis. From 2004-2012 it was awarded biennially, and since 2012 has been annual.
Medallists.
Source: Royal Astronomical Society