Presentation #203.03 in the session Habitability.
The Exoplanet Science Strategy report identified the “presence and strength of a global-scale magnetic field, which depends on [a planet’s] interior composition and thermal evolution” as a potential factor for determining a planet’s habitability. Specifically, a planetary-scale magnetic field can shield a planet’s atmosphere from erosion by the host star’s stellar wind. In the Solar System, a dramatic illustration of the erosion of a planet’s atmosphere has been provided by data from the Mars Atmosphere and Volatile EvolutioN (MAVEN) mission.
A combination of remote sensing and in situ spacecraft measurements have revealed that many of the planets in the Solar System, and even some moons, have or have had large-scale magnetic fields. These magnetic fields are (or have been) generated by interior dynamo processes. As such, detecting extrasolar planetary magnetic fields provide a remote sensing means of constraining extrasolar planetary properties that will be otherwise difficult to access.
In the case of the Earth, Jupiter, Saturn, Uranus, and Neptune, the interaction between the solar wind and their magnetic fields generates intense radio emission via the electron cyclotron maser instability. Extrasolar planets may reasonably be expected to generate large-scale magnetic fields and sustaining an electron cyclotron maser instability. I summarize the current state of field for extrasolar planetary magnetic fields and radio searches for extrasolar planets, along with projections for the near future from both new telescopes and new Solar System missions, such as an Ice Giant mission.
Some of the information presented is pre-decisional and for planning and discussion purposes only. Part of this research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration.