One of the Most Perplexing Issues Raised by the Discovery

Multiple Choice

One of the most perplexing issues raised by the discovery of thousands of exoplanets is the existence of "hot Jupiters" - planets with the masses and compositions of Jupiter, but orbiting closer to their stars than Mercury does in our solar system. What is our best idea currently about how such "hot Jupiters" came to be?

A) each hot Jupiter came directly out of the star it now orbits and must be made of the exact same material at only slightly lower temperatures
B) hot Jupiters formed by the collision and merger of many terrestrial planets - these collisions heated them up
C) hot Jupiters formed in an asteroid belt and are made of countless asteroids that are hot
D) hot Jupiters formed further out in their star system, and then migrated inward somehow
E) hot Jupiters are artificial; they were made by super-advanced alien beings to make the universe more interesting
Section 14.5: Planetary Evolution