Given a context passage, generate a question from the passage such that its answer is shortest continous span from the passage.

9134 Encke (4822 P-L) is an asteroid-belt asteroid discovered on 24 September 1960 by Cornelis Johannes van Houten and Ingrid van Houten-Groeneveld at Leiden University, on photographic plates from the Palomar Observatory.
What is the year 9134 Encke discovered?