Two Baby Alien Worlds Show Us How to Cook a Planet

Two new exoplanets have been discovered, and they're important milestones in our understanding of how alien solar systems behave. That's because both are very young, both are massive, and both orbit their stars very close in, closer than Mercury orbits the Sun. First, a quick intro to the problem: When astronomers first started finding planets around other stars in the mid-1990s, they were surprised to find that many were as big and massive as Jupiter but so close to their parent stars that they...