Why did the discovery of a 17 Earth mass terrestrial exoplanet surprise astronomers?
A) It implies that Earth lost a great deal of mass in the early solar system.
B) Such a large planetary mass was thought to be gravitationally unstable.
C) Models had predicted that the formation of such a large rocky core requires a protoplanetary disk many times larger than that of the solar system.
D) Models had predicted that a rocky protoplanet of such a mass would attract enough hydrogen to form a gas giant.

Question

Quizplus · Accepted Answer

Models had predicted that a rocky protoplanet of such a mass would attract enough hydrogen to form a gas giant, making the discovery of a 17 Earth mass terrestrial exoplanet surprising because it challenges existing theories on planet formation and the conditions required for the development of gas giants versus terrestrial planets.

Why Did the Discovery of a 17 Earth Mass Terrestrial