There have been four successful robotically operated Mars rovers, all managed by the Jet Propulsion Laboratory: Sojourner, Opportunity, Spirit and Curiosity. On January 24, 2016, NASA reported that current studies on Mars by Curiosity and Opportunity (the latter now defunct) would be searching for evidence of ancient life, including a biosphere based on autotrophic, chemotrophic or chemolithoautotrophic microorganisms, as well as ancient water, including fluvio-lacustrine environments (plains related to ancient rivers or lakes) that may have been habitable. The search for evidence of habitability, taphonomy (related to fossils), and organic carbon on Mars is now a primary NASA objective. In June 2018, Opportunity went out of contact after going into hibernation mode in a dust storm. NASA declared the end of the Opportunity mission on February 13, 2019, after numerous failures to wake up the rover.
The original goal of Cassini-Huygens was to study Saturn and its large, misty, tortured, moon Titan. Titan, the second-largest moon in our Solar System, after Ganymede of Jupiter, is a world long-shrouded in mystery, hiding behind a thick orange veil, and slashed with hydrocarbon lakes and seas. However, there are other enticing moons known to circle the ringed planet. Saturn's mid-sized icy moons (Mimas, Enceladus, Tethys, Dione, Rhea, Hyperion, Iapetus, and Phoebe) are enchanting worlds. Each one of these frozen little moons reveals an interesting and unique geology. So far, Saturn is known to sport 62 icy moons! Despite this oddball moon's many exotic attributes, it actually sports one of the most Earth-like surfaces in our Solar System. Titan may also experience volcanic activity, but its volcanoes would erupt with different ingredients than the molten-rock lava that shoots out from the volcanoes of Earth. In dramatic contrast to what occurs on our own planet, Titan's volcanoes erupt icy water "lava" (cryovolcanism). Titan's entire alien surface has been sculpted by gushing methane and ethane, which carves river channels, and fills its enormous great lakes with liquid natural gas. The moon plays a large role in astrology and astrological phenomena. The position and phase of the moon influences the other aspects of astrology, including sun signs and planetary movements. In fact, the moon influences other aspects of astrology as a whole.