Concept explainers
Habitable Planets? Roles: Scribe (takes notes on the group’s activities), Proposer (proposes explanations to the group), Skeptic (points out weaknesses in proposed explanations), Moderator (leads group discussion and makes sure everyone contributes). Activity: List the hypothetical planets described below in order from most likely to support life to Least likely to support life, and explain your reasons for each ranking.
a. a planet orbiting a star of spectral type B (approximately 10 solar masses) in a circular orbit and having an expected average temperature of 300 K b. a planet orbiting a Sun-like star in a circular orbit at a distance twice Earth’s orbital distance from the Sun c. a planet orbiting a star with a luminosity one-quarter the Sun’s luminosity in a circular orbit at a distance one- half Earth’s orbital distance from the Sun d. a planet orbiting a Sun-like star in an elliptical orbit ranging from Earth’s orbital distance to 10 times Earth’s orbital distance from the Sun
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