1. The Earthiest Kepler-78b is most similar to Earth in mass, diameter and composition; it could be made of rock with an iron core. But it’s no Earth analog, whizzing around its star in 8.5 hours, with temperatures exceeding 2,000° Celsius (SN Online: 10/30/13). 2. The wettest HR 8799c’s atmosphere lacks methane, which could signal life, but does have water and carbon monoxide (SN: 4/6/13, p. 5). Water has also been found in the atmospheres of WASP-17b, HD209458b, WASP-12b, WASP-19b and XO-1b. 3. The rogue Planetary candidate PSO J318.5-22 has no parent star. The object is roughly six times the...
