Transit of Earth from Mars
This will never be visible in our lifetime unless humans establish a permanent presence on Mars, which will likely not happen anytime soon. As spectacular as it would be to watch our planet from Mars, it’s more likely we’re stuck here for the time being.
According to Sky and Night magazine, “A transit of Earth can be seen from Mars in intervals of between 25 and 100 years. These transits usually occur in pairs 79 years apart, similar to the transits of Venus seen from Earth (where pairs of transits are 8 years apart, but the pairs themselves are over 100 years apart).” At the very least, this is something our grandchildren might be able to see (Sky at Night Magazine).