What size telescope is needed to see the moons of Mars transit the planet?
The moons of Mars can be observed when at maximum elongation (farthest from the planet) with a 12″ telescope equipped with very clean optics and an occulting bar. They can never be observed when in transit in front of the planet itself…they are just too small. Even Io and Europa tend to disappear when in front of Jupiter…the only Jovian moons I’ve been able to follow across the face of Jupiter are Ganymede and Callisto, which are dark in colour compared to the background of the planet.
