Bohr received numerous honours and accolades. In addition to the Nobel Prize, he received the Hughes Medal in 1921, the Matteucci Medal in 1923, the Franklin Medal in 1926, the Copley Medal in 1938, the Order of the Elephant in 1947, the Atoms for Peace Award in 1957 and the Sonning Prize in 1961. He became foreign member of the Finnish Society of Sciences an Letters in 1922, and of the Royal Netherlands Academy of Arts and Sciences in 1923, an international member of the United States National Academy of Sciences in 1925, a member of the Royal Society in 1926, an international member of the American Philosophical Society in 1940, and an international honorary member of the American Academy of Arts and Sciences in 1945. The Bohr model's semicentennial was commemorated in Denmark on 21 November 1963 with a postage stamp depicting Bohr, the hydrogen atom and the formula for the difference of any two hydrogen energy levels: h ν ν = ϵ ϵ 2 − − ϵ ϵ 1 . Several other countries have also issued postage stamps depicting Bohr. In 1997, the Danish National Bank began circulating the 500-krone banknote with the portrait of Bohr smoking a pipe. On 7 October 2012, in celebration of Niels Bohr's 127th birthday, a Google Doodle depicting the Bohr model of the hydrogen atom appeared on Google's home page. An asteroid, 3948 Bohr, was named after him, as was the Bohr lunar crater and bohrium, the chemical element with atomic number 107.