The Exoplanet Revolution
Dr. Brian Jackson
Dept. of Physics
Boise State University
The discoveries of hundreds of planets outside our solar system, called exoplanets, have led to a renaissance in astrophysics and revolutionized every sub-discipline within planetary astronomy. The vast array of new planets strains imagination, and even after two decades of discovery, exoplanets pose a host of astrophysical riddles.
Our rich understanding of the Solar System provides a basis upon which we can concoct theories regarding the origins and fates of exoplanets. For example, the same kind of gravitational interactions that drive gentle orbital oscillations for planets in our solar system cause some exoplanetary systems to teeter on a knife-edge, with planets gravitationallyDD ejected from their maternal system by sibling planets. The same tidal interactions that push the Moon away from the Earth at a few cm each year draw some exoplanets into a death-spiral with their host stars.
These theoretical results provide predictions that have been tested in many cases by ongoing observational work. Using data from the Kepler planet-hunting mission, astronomers have found planets so close to their host stars that the planets are actively disintegrating under the intense starlight. One planetary candidate is so near to its host star it has an orbital period shorter than a Peter Jackson movie. These planets may be the ones on the verge of a final, tidally-induced tumble into their host stars.
In this presentation, I'll describe how these distant worlds have revised our picture of planet formation and evolution. I'll also discuss outstanding questions in planetary astrophysics and prospects for observational work, including the TESS mission, selected by NASA for a 2017 launch to find more, nearby planets.