Lightning sprite with streamers. Image Credit: American Friends of Tel Aviv University (AFTAU)
more times more powerful than those on Earth, according to Ph.D. student
Daria Dubrovin. With her supervisors Prof. Colin Price of TAU’s
Department of Geophysics and Planetary Sciences and Prof. Yoav Yair of
the Open University of Israel, and collaborators Prof. Ute Ebert and Dr.
the presence of sprites in space.
atmospheres. This research, which was presented in October at the
Image Credit: Abestrobi
Lightning sprites and extraterrestrial life?
Though a little-known atmospheric phenomenon, sprites are quite
common on Earth, says Dubrovin. Because they occur in the mesosphere — a
layer of the atmosphere that is not regularly observed by satellites
and too high to be reached by atmospheric balloons — the discovery of
these electric discharges – which are red in color and last only a few
tens of milliseconds – was a stroke of luck.
Lightning, as a generator of organic molecules, is credited for
contributing to the “primordial soup” that, according to current
theories, led to the emergence of life on Earth. Researchers are keen to
know more about the possibility of lightning on other planets, explains
Dubrovin, not only because it impacts the technological equipment used
by space programs, but because it is another clue that could indicate
the presence of extraterrestrial life.
Image Credit: Walter Lyons, FMA Research, Fort Collins, Colorado
To test for the viability of extraterrestrial sprites, Dubrovin and
her fellow researchers re-created the atmospheres of Jupiter, Saturn,
and Venus in small containers. A circuit that creates strong
short-voltage pulses produced a discharge that mimics natural sprites.
Images of these discharges, known as streamers, were taken by a fast and
sensitive camera, then analyzed. Quantifying factors such as
brightness, color, size, radius, and speed could help researchers
measure how powerful extraterrestrial lightning actually is, she notes.
Smiling, Dubrovin said:
Will Cassini spacecraft study sprites in Saturn’s atmosphere?
We make sprites-in-a-bottle.
Dubrovin believes that the team’s predictions could convince
scientists operating the Cassini spacecraft — now orbiting Saturn as
part of an ESA/NASA mission — to point their cameras in a new direction.
Currently, she says, there is a huge lightning storm occurring on
Saturn producing at least 100 lightning discharges per second — a rare
event that happens approximately once in a decade. Above the
lightning-producing clouds in Jupiter’s and Saturn’s atmosphere,
Dubrovin explains, lies a layer of clouds which partly obscure the light
from the flashes. If researchers were able to obtain an image of the
higher-up sprites from the Cassini craft, it would enable them to gain
more information about the storm below.