I'm going to regret this later, but how would humans going to Mars expose the bunnies as anything? Are there bunnies on Mars or something?
Here's info on their origin: The Constellation Lepus:
Lepus, the Hare, was one of the animals that the great hunter Orion most delighted in pursuing. Lepus was thus honored a place among the stars. Crouching low on the horizon., The Hare tries to remain unnoticed as it endlessly attempts to escape Orion's attention and attack, Through the legend of Lepus, the timid hare is seen fleeing before Orion as The Hunter is poised to attack the onrushing bull, Taurus. Meanwhile, the fierce monster of the deep, Cetus the Whale, eagerly seeks any prey that he may savagely devour, and The Champion, Perseus, with drawn sword, stands ever ready to join in mortal combat.
THE HARE