Ceres, the largest object in the asteroid belt – and the smallest known dwarf planet – is 590 miles (950 kilometers) in diameter.
Its orbit between Mars and Jupiter takes 4.6 Earth years to complete. A day on Ceres is 9 hours and 4 minutes long.
Ceres may have a thin atmosphere and possibly an ocean of water beneath its surface. No one could live unprotected on the surface, but future astronauts could mine water from Ceres to create oxygen and rocket fuel. Gravity on Ceres is about 2.8 percent of that on Earth. The surface temperature ranges from minus 100 degrees F (minus 73 degrees C) to minus 225 F (minus 143 C).
Source SPACE.com: All about our solar system, outer space and exploration.
Source: http://www.space.com/28595-living-on-asteroids-dwarf-planet-ceres-infographic.html