[Note: These speculations are out of date and will be updated in coming weeks.] 47 Ursae Majoris b, like 70 Virginis b, is a very promising world. It too lies with in the right distance range from its sun for liquid water to exist, lending more hope that one day Earth-like worlds may be detected at habitable orbits around sun-like stars. But unlike hot 70 Virginis b, 47 Ursae Majoris b is a cooler place. Twice the distance from 47 Ursae Majoris than Earth is from our own sun, 47 Ursae Majoris b is colder than Mars. Like 70 Virginis b and Jupiter, 47 Ursae Majoris b is not likely to have an abundance of water in the atmosphere, although this is not a certainty. But frozen water could be found on the moons of 47 Ursae Majoris b. In the case of hot 70 Virginis b, the moons are entirely rocky, like Mars or Mercury. Jupiter's moons, significately further out from the sun, have rocky cores but substantial mantles of water ice. Farther out still, the moons of Saturn are probably all or mostly ice, with surfaces of frozen methane. The more distant a non-jovian world is from its sun, the more ice and the less rock it contains. So the moons of 47 Ursae Majoris b, not as scalded as those of 70 Virginis, and not as frozen as those of Jupiter, exist at a medium. They probably have rocky cores and mantles, but their surfaces may be thick with ice. Larger more tectonically active moons will have channels and valleys where rivers of water were melted by geothermic heat and then frozen again after the heat disapated. Meteoric impacts would also melt the ice into running streams of water. Such features can be seen on Mars, where volcanic eruptions heated subsurface ice into rivers which cut channels into the terrain until the water froze once more. One very interesting possibility is that one of the larger, tectonically active moons may hide a global ocean under a thin crust of ice. Heated by volcanism and ocean floor fumerals, such dark oceans may be warm enough for life to thrive. There is actually support for this possibility in our own solar system. Many astronomers speculate that the Jovian moon Europa itself has a deep ocean of water, headed by tidal fiction caused by it's close orbit to Jupiter, underneath its icy surface. Deep below the frozen surface of a moon of 47 Ursae Majoris b may be seas of water teeming with swimming creatures which have never seen sunlight.
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