Due to an ancient collision with an object roughly the size of Mercury, Mars was nearly annihilated, and its magnetosphere was destroyed in OTL. However, in this timeline, that object, along with the asteroid belt, collided with mars much sooner, thereby increasing its mass to nearly earth-like proportions. The surface of this new Mars is 90% water. In addition, a series of islands and archipelagos, though not as numerous as those found on Venus, are also found, making up roughly one percent of the landmasses. Mars has two moons as of now; Phobos and Deimos, which did not begin with life, though they have been hollowed out and the inner surface has been made habitable by the Martians.
The Zanturans are the native sentient species of Mars, having a humanoid/squid like appearance. They stand upright, have elongated tentacles used for walking, with modified suction cups acting in place of feet/toes to stabilize walking on land. Their body is shaped like an upside-down bell, with legs coming out the bottom, an arms emerging from the top shoulder area. From there the bell-shaped head meets the shoulders on a minuscule neck. The head has large black eyes five centimeters in diameter, and a mouth full of teeth, used for chewing, biting, and grinding. The ear is generally kept within a pocket on either side of the head, which is then filled with water to equalize pressure and hear sounds with better definition. When a Zanturn emerges onto land, the pockets will open open, draining of water and filling with air, thereby allowing it to hear both in and out of the water with eloquence. Sometime between first contact and gained sentience, though probably closer to the former, the Zanturans became space-faring, and used this skill to hollow out a massive spherical cavity between the surface and the core of both Phobos and Deimos, leaving it half-filled with sea water, to form two space stations, of sorts.