NASA's Universe of Learning materials are based upon work supported by
under award number NNX16AC65A to the
Space Telescope Science Institute,
Chandra X-ray Center,
Jet Propulsion Laboratory-Exoplanet Exploration Program,
Sonoma State University.
Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Aeronautics and Space Administration.