% X9 s) n7 D+ A( p' UCOVER Stylized comparison of the inner solar system (top) and " s" ~! S, G; L$ U3 V' q, S$ \9 R' XKepler-62 (bottom), a five-planet system about 1200 light-years away. Like our $ i/ K: r# o& Y5 d: z3 u
solar system, Kepler-62 hosts two planets in its habitable zone (depicted in 7 P `( M. t% W. [6 f+ h8 agreen), the region around a star where a planet could conceivably maintain 5 M9 h0 p7 J2 g. N; z
liquid water on its surface. The special section beginning on page 565 ! i6 t. t, L3 h9 q4 j' ^5 Esummarizes what we currently know about extrasolar planets. Illustration: + V2 y6 c( g: Q- S2 P! E/ [' MNASA/Jet Propulsion Laboratory–Caltech/T. Pyle : U+ [- h, i+ f9 Z: o作者: 452359357 时间: 2013-5-3 13:56