Although the comet 55P/Tempel-Tuttle was observed by Gottfried Kirch in 1699, it was not recognized as a periodic comet at the time. 55P/Tempel-Tuttle was independently discovered on December 19th, 1865 by Ernst Wilhelm Liebrecht Tempel in Marseilles, France and Horace Parnell Tuttle of Harvard College Observatory, Cambridge, Massachusetts, USA on January 6th, 1866.
Ernst Wilhelm Liebrecht Tempel was born in 1821 in Nieder-Kunersdorf, in Saxony. Although he worked as a lithographer, astronomy was his hobby. Using a 4 inch refractor on a balcony of a Venetian palace, he discovered his first comet in 1859. That same year, he became the first observer to note the nebula around the star Merope in the Pleiades. His early discoveries allowed him to obtained employment at the observatory in Marseilles, France in 1860 where he discovered 8 more comets, including Tempel-Tuttle.
Eleven years later, Tempel accepted a position as an assistant to Schiaparelli at the Brera Observatory in Milan, Italy. He discovered 3 more comets there before moving to the Arcetri Observatory in Florence in 1874, where he had access to larger telescopes. There he made his final discovery of a comet, bringing his total to 13.
Ernst Wilhelm Liebrecht Tempel died in 1889.
Horace Parnell Tuttle was born on March 24, 1839. As an assistant astronomer at the Harvard College Observatory, he spotted his first comet in 1857, which turned out to be periodic Comet Brorsen. The following year, he made a first discovery of Comet 1858 I, now called periodic Comet Tuttle.
Tuttle decided to leave Harvard to serve in the infantry during the US Civil War, later transferring to the Navy. During the day he was a Navy paymaster, but at night, he worked at his real love, searching the night skies for comets. During his life, he eventually made a total of 4 comet discoveries, and 9 co-discoveries. Besides Tempel-Tuttle, he had earlier been a co-discoverer of Swift-Tuttle in 1862.
After the navy, Horace Parnell Tuttle worked with the U.S. Geological Survey. He died in 1923 and is buried in an unmarked grave at the Oakwood Cemetery in Falls Church, Virginia.