Mars rover current studies on Mars by the "Curiosity" "Opportunity" rovers 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. Since June 2018, the "Opportunity" rover has been out of contact after going into hibernation mode in a dust storm. NASA has stated they are unsure if they will ever be able
Gliese 687 40% of the Sun's mass and nearly 50% of the Sun's radius. Compared to the Sun, it has a slightly higher proportion of elements with higher atomic numbers than helium. It appears to have a rotation of 60 days and to be somewhat chromospherically active. It displays no excess of infrared radiation that would indicate orbiting dust. It is known to have a planet, Gliese 687 b, with a mass of 18.394 Earth masses (which makes it comparable to Neptune), an orbital period of 38.14 days, and a low orbital eccentricity. Gliese 687 is a solitary red dwarf that emits