This table summarizes in eighteen thermal-mass categories most of the current known exoplanets (as of October 2011). Planets are divided in six mass classes as mercurians, subterrans, terrans, superterrans, neptunians, and jovians. Planets in the hot zone (first row) are too close to the stars to support liquid water. Planets in the habitable zone (second row) can sustain liquid water if large enough. Planets in the cold zone (third row) are icy-rich bodies. The mean mass (M) and radius (R) of the exoplanets in each category is shown at the bottom of the frames.
In the Solar System Mercury is an example of a hot mercurian, Venus is on the edge of a hot and warm terran, Mars is on the edge of a warm subterran and mercurian, Jupiter and Saturn are cold jovians, and Uranus and Neptune cold neptunians. Only warm subterrans, terrans, and superterrans are potentially habitable, although warm jovians might have habitable exomoons. The only known mercurian was discovered in the Arecibo Observatory. You can click the image for a higher resolution version. An updated of this table will be available for the Habitable Exoplanets Catalog.