Roughly how often does a Martian opposition, providing the best visibility, occur?
Answer
Roughly every 26 months
Since Mars orbits the Sun in approximately 687 Earth days, an opposition occurs roughly every 26 months, offering predictable windows for observation.

Related Questions
What term did Giovanni Virginio Schiaparelli use to describe the faint, dark lines he observed on Mars in 1877?What physical characteristics made Flagstaff, Arizona, an ideal location for Percival Lowell's observatory?Which specific Martian opposition event initiated Lowell’s detailed mapping and public campaign regarding Martian canals?According to Lowell’s hypothesis, what was the primary function of the artificial canals he observed?What was Lowell's primary instrument used to record the features he perceived on Mars?For approximately how long did Lowell’s dedicated observational period pursuing the canal theory span?What did the English translation of Schiaparelli's *canali* readily imply about the Martian features he saw?What allowed Lowell’s long-term observation campaign to proceed according to his own timeline rather than external schedules?When did Percival Lowell cease his personal, intense observational tenure on Mars?Roughly how often does a Martian opposition, providing the best visibility, occur?