Passage: Palisa was born on December 6, 1848 in Troppau in Austrian Silesia (now called Opava and located in the Czech Republic). From 1866 to 1870, Palisa studied mathematics and astronomy at the University of Vienna; however, he did not graduate until 1884. Despite this, by 1870 he was an assistant at the University's observatory, and a year later gained a position at the observatory in Geneva. A few years later, in 1872, at the age of 24, Palisa became the director of the Austrian Naval Observatory in Pula. While at Pula, he discovered his first asteroid, 136 Austria, on March 18, 1874. Along with this, he discovered twenty-seven minor planets and one comet. During his stay in Pula he used a small six-inch refractor telescope to aid in his research.Palisa became director of the Pula observatory, with the rank of commander, until 1880. In 1880 Palisa moved to the new Vienna Observatory. While at the observatory he discovered 94 comets by visual means.In 1883 he joined a French expedition to Caroline Island to observe the Solar eclipse of May 6, 1883. During the expedition, he joined to observations for the search for the hypothetical planet  Vulcan, as well as collecting samples of insects for the Vienna Museum of Natural History. In memory of this expedition, he named the asteroid 235 Carolina after Caroline Island.In 1885, Palisa offered to sell the naming rights of some of the minor planets he discovered, in order to fund his travels to observe the Solar eclipse of August 29, 1886. However he sold just a small number of these naming rights and apparently did not go.Palisa and Max Wolf worked together to create the first star atlas created by photographic plates, the Palisa–Wolf Sternkarten, published on 1899, 1902, 1908. In 1908, Palisa published the Sternenlexikon, mapping the skies from declinations -1° to +19°.. That same year, he became the vice director of the Vienna Observatory. He retired from administrative duties in 1919, but kept observation rights. Palisa continued to discover asteroids until 1923. He...

Question: How old was Palisa when he became director in Pula?
24