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".

[1][2] 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.

Source: Royal Astronomical Society