Detailed Instructions: Given a question and a context passage, generate the answer having the word or phrase from the context passage. Here, the answer should be a shortest continous span from the passage.
Problem:Context: Bahram Vallis is an ancient river valley in the Lunae Palus quadrangle of Mars at 20.7 north latitude and 57.5 west longitude.
Question: The astronomical body that Bahram Vallis was located on was what?
Solution:
mars