YAHOO.COM - Scientists have kept a close watch on the dazzling northern lights on
Earth and other planets in our solar system, but now they have the
chance to explore the auroras of alien planets orbiting distant stars, a
new study suggests.
Auroras on Earth occur when charged particles from the sun are funneled
to the planet's poles and interact with the upper atmosphere, sparking
spectacular light shows. Similar processes have been observed on other
planets in the solar system, with Jupiter's auroras more than 100 times brighter than those on Earth, scientists said.
Now, scientists are finding evidence of aurora displays on exoplanets for
the first time. Researchers used the Low-Frequency Array radio
telescope based in The Netherlands to observe radio emissions most
likely caused by powerful auroras from planets outside of our solar
system.
"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.
Jupiter's auroras are caused by an interaction of charged particles
shot from its volcanic moon, Ibo and the rotation of the planet itself.
The gas giant turns on its axis once every 10 hours, dragging its
magnetic field along for the ride, and effectively creating a whirl of
electricity at each of the planet's poles.
Auroras akin to Earth's
have been spotted on Saturn. But these newest findings show that
auroras on exoplanets probably aren't formed from charged particles
traveling on the solar wind. Instead, the auroras on the dim,
"ultracool dwarf" stars and "failed stars" known as brown dwarfs that
Nichols studied probably behave more like Jupiter's northern and
southern lights.
By studying these radio emissions, scientists will gain more insight
into the strength of a planet's magnetic field, how it interacts with
its parent star, whether it has any moons and even the length of its
day.
The new research is detailed in a recent issue of The Astrophysical Journal.