Humans have studied aurorae in one way or another since at least 700 A.D., according to NASA, fascinated by the spectacular natural phenomenon of mysterious lights painting vibrant colors across Earth's skies. Now we have the chance to explore the aurora of far away alien planets orbiting distant stars, a new study suggests.
Auroras occur on Earth when charged particles from the sun are funneled to our planet's poles and interact with the upper atmosphere, creating fantastic light shows. Scientists have found similar processes on other planets in our solar system, such as Jupiter, whose aurorae are more than 100 times brighter than those above Earth, according to Space.com.
But a new study found evidence of aurora displays on exoplanets for the first time ever. Using the Low-Frequency Array radio telescope based in the Netherlands, researchers were able to observe radio emissions that were most likely caused by strong auroras from planets outside our own solar system, scientists announced.
"These results strongly suggest that auroras do occur on bodies outside our solar system, and the auroral radio emissions are powerful enough - 100,000 times brighter than Jupiter's - to be detectable across interstellar distances," study lead author Jonathan Nichols, of the University of Leicester in England, said in a statement.
Exoplanets are planets outside of our solar system. Since the first discovery of an exoplanet in 1992, astronomers have discovered around 837 exoplanets in 660 planetary systems around the Milky Way Galaxy, according to Space.com. Most of the exoplanets discovered don't resemble Earth, but rather have characteristics more similar to gas giants like Neptune or Jupiter.
Jupiter's auroras are unique relative to those of Earth. The king planet's aurorae are caused by an interaction between charged particles shot from its volcanic moon, Io, and the planet itself. As Jupiter turns on its axis once every 10 hours, the planet drags its magnetic field along with it, creating a "whirl" of electrical activity at each of the planet's poles.
Saturn has similar aurorae to that of Earth, but the new findings indicate that auroras on exoplanets aren't likely formed from charged particles traveling on the solar wind, according to Space.com. Nichols believes the auroras he studied on the dim, "ultracool dwarf" stars and "failed stars," attractively referred to as brown dwarfs, likely behave more akin to Jupiter's northern and southern lights.
Nichols said he hopes studying the radio emissions will shed more light on the strength of a planet's magnetic field, the length of its day, how it interacts with its parent star, and even whether or not any moons orbit it.