Lightning Could Shed Light on Solar System's Origins
In a paper published on May 1 in The Astrophysical Journal, researchers describe how this new technique could be used to study other planets in the Solar System as well, and even shed light on how the Solar System formed. Studying the origin and evolution of our solar system is important for astrobiologists who are trying to understand how the Earth developed into a habitable planet. This information could shed light on the origin of life on Earth, and the potential for habitable, Earthlike worlds in the Universe.
"The frequency of Schumann Resonance depends not only on the size of the planet but on what kinds of atoms and molecules exist in the atmosphere because they change the electrical conductivity," says Fernando Simoes, the first author on this paper and a space scientist at NASA's Goddard Space Flight Center in Greenbelt, MD. "So we could use this technique remotely, say from about 600 miles above a planet's surface, to look at how much water, methane and ammonia is there."
Water, methane and ammonia are collectively referred to as "volatiles" and the fact that there are different amounts on different planets is a tantalizing clue to the way the planets formed. Determining the composition of a planet's atmosphere can be done with a handful of other techniques -- techniques that are quite accurate, but can only measure specific regions. By looking at the Schumann Resonance, however, one can get information about the global density of, say, water around the entire planet. Simoes and his colleagues believe that combining this technique with other instruments on a spacecraft's visit to a planet could provide a more accurate inventory of the planet's atmosphere.
Accurate descriptions of planetary atmospheres might also help shed light on how the evolution of the Solar System left the outer planets with a high percentage of volatiles, but not the inner planets.
Detecting Schumann Resonance from above still requires the instruments to be fairly close to the planet, so this technique couldn't be used to investigate from afar the atmospheres of planets outside our solar system. Instead, scientists imagine something much more dramatic. After a spacecraft is finished observing a planet, it could continue to detect Schumann resonance as it begins its death dive into the atmosphere. During the process of self-destruction, the spacecraft would still provide valuable scientific data until the very last minute of its existence.