Element 104 is unofficially named Rutherfordium (Rf) in honor of Ernest Rutherford, a New Zealand physicist. It was discovered by Ghiorso, Nurmiam Harris, K. Eskola and P. Eskola at Berkeley in 1969. In 1964 at the Joint Nuclear Research Institute in Russia, it was identified as kurchatovium or symbol Ku. Elements 104 through 109 have systematic names. All these elements were prepared by bombarding uranium nuclei or other atoms with atomic particles.