Thursday, March 18, 2010
Today's announcement of a newly-discovered gas giant planet with what seems to be a fairly temperate climate (-20 to 160 degrees Celsius) is probably this year's most exciting exoplanet discovery so far, simply because all the gas giants discovered thus far have been in some pretty odd orbits whereas this one is quite normal, orbiting its parent star every 95 days (Mercury is every 88 days) and also with a low eccentricity of 0.11 (Mars is 0.09), giving it a mostly circular orbit.
An article here speculates that this planet could have moons like Pandora in Avatar. It's not certain yet what moons orbit this planet but we are certain that there are no bodies five times greater than the Earth in mass, as that would have been detected already. Of course, its distance of 1500 light years makes it far too distant to explore even with prospective next-generation propulsion that could send probes to nearby solar systems.
The planet transits in front of its star for eight hours every time it makes a pass in front of it every 95 days, so that gives us almost four chances per year to refine what we know about it.