
This artist's concept shows a gas giant planet orbiting the cool red dwarf star Gliese 876.
When struck by high energy particles in the solar wind, an exoplanet's magnetic field may produce radio signals from auroras in the planet's atmosphere. While current telescopes have yet to pick up these crackles, it's an area worth exploring, argue Joseph Lazio at the Naval Research Laboratory in Washington DC and colleagues in a paper submitted to Astro2010.
Because a magnetic field helps to preserve atmospheres and oceans, a magnetosphere may signify that a planet has complex surface life. "This is something we think is worth studying at a modest level," says Lazio, "the payoff could be immense."









