Herschel wrote many papers and articles, including entries on meteorology, physical geography and the telescope for the eighth edition of the Encyclopædia Britannica. He also translated the Iliad of Homer.
In 1823, Herschel published his findings on the optical spectra of metal salts.
Herschel invented the actinometer in 1825 to measure the direct heating power of the Sun's rays, and his work with the instrument is of great importance in the early history of photochemistry.
Herschel proposed a correction to the Gregorian calendar, making years that are multiples of 4000 common years rather than leap years, thus reducing the average length of the calendar year from 365.2425 days to 365.24225. Although this is closer to the mean tropical year of 365.24219 days, his proposal has never been adopted because the Gregorian calendar is based on the mean time between vernal equinoxes (currently  days).
Herschel was elected a Foreign Honorary Member of the American Academy of Arts and Sciences in 1832, and in 1836, a foreign member of the Royal Swedish Academy of Sciences. 
In 1835, the New York Sun newspaper wrote a series of satiric articles that came to be known as the Great Moon Hoax, with statements falsely attributed to Herschel about his supposed discoveries of animals living on the Moon, including batlike winged humanoids.
Several locations are named for him: the village of Herschel in western Saskatchewan, Canada, site of the discovery of  Dolichorhynchops herschelensis, a type of plesiosaur; Mount Herschel in Antarctica; the crater J. Herschel on the Moon; and the settlement of Herschel, Eastern Cape and the Herschel Girls' School in Cape Town, South Africa.
While it is commonly accepted that Herschel Island, in the Arctic Ocean, part of the Yukon Territory, was named after him, the entries in the expedition journal of Sir John Franklin state that the latter wished to honour the Herschel family, of which John Herschel's father, Sir William Herschel, and his aunt, Caroline Herschel, are as notable as John.