NASA's Maven observes Martian night sky pulsing in ultraviolet light


Date:
August 6, 2020
Source:
NASA/Goddard Space Flight Center
Summary:
Vast areas of the Martian night sky pulse in ultraviolet light,
according to images from NASA's MAVEN spacecraft. The results
are being used to illuminate complex circulation patterns in the
Martian atmosphere


FULL STORY ========================================================================== [This is an image of the | Credit: NASA/MAVEN/Goddard Space Flight
Center/CU/ LASP] This is an image of the ultraviolet 'nightglow' in the
Martian atmosphere.

Green and white false colors represent the intensity of ultraviolet light,
with white being the brightest. The nightglow was measured at about 70 kilometers (approximately 40 miles) altitude by the Imaging UltraViolet Spectrograph instrument on NASA's MAVEN spacecraft. A simulated view
of the Mars globe is added digitally for context. The image shows an
intense brightening in Mars' nightside atmosphere. The brightenings occur regularly after sunset on Martian evenings during fall and winter seasons,
and fade by midnight. The brightening is caused by increased downwards
winds which enhance the chemical reaction creating nitric oxide which
causes the glow.

Credit: NASA/MAVEN/Goddard Space Flight Center/CU/LASP [This is an image
of the | Credit: NASA/MAVEN/Goddard Space Flight Center/CU/ LASP] This
is an image of the ultraviolet 'nightglow' in the Martian atmosphere.

Green and white false colors represent the intensity of ultraviolet light,
with white being the brightest. The nightglow was measured at about 70 kilometers (approximately 40 miles) altitude by the Imaging UltraViolet Spectrograph instrument on NASA's MAVEN spacecraft. A simulated view
of the Mars globe is added digitally for context. The image shows an
intense brightening in Mars' nightside atmosphere. The brightenings occur regularly after sunset on Martian evenings during fall and winter seasons,
and fade by midnight. The brightening is caused by increased downwards
winds which enhance the chemical reaction creating nitric oxide which
causes the glow.

Credit: NASA/MAVEN/Goddard Space Flight Center/CU/LASP Close Vast areas
of the Martian night sky pulse in ultraviolet light, according to images
from NASA's MAVEN spacecraft. The results are being used to illuminate
complex circulation patterns in the Martian atmosphere.


==========================================================================
The MAVEN team was surprised to find that the atmosphere pulsed exactly
three times per night, and only during Mars' spring and fall. The new
data also revealed unexpected waves and spirals over the winter poles,
while also confirming the Mars Express spacecraft results that this
nightglow was brightest over the winter polar regions.

"MAVEN's images offer our first global insights into atmospheric motions
in Mars' middle atmosphere, a critical region where air currents carry
gases between the lowest and highest layers," said Nick Schneider of the University of Colorado's Laboratory for Atmospheric and Space Physics
(LASP), Boulder, Colorado. The brightenings occur where vertical
winds carry gases down to regions of higher density, speeding up the
chemical reactions that create nitric oxide and power the ultraviolet
glow. Schneider is instrument lead for the MAVEN Imaging Ultraviolet Spectrograph (IUVS) instrument that made these observations, and lead
author of a paper on this research appearing August 6 in the Journal of Geophysical Research, Space Physics. Ultraviolet light is invisible to
the human eye but detectable by specialized instruments.

"The ultraviolet glow comes mostly from an altitude of about 70
kilometers (approximately 40 miles), with the brightest spot about a
thousand kilometers (approximately 600 miles) across, and is as bright
in the ultraviolet as Earth's northern lights," said Zac Milby, also
of LASP. "Unfortunately, the composition of Mars' atmosphere means that
these bright spots emit no light at visible wavelengths that would allow
them to be seen by future Mars astronauts.

Too bad: the bright patches would intensify overhead every night
after sunset, and drift across the sky at 300 kilometers per hour
(about 180 miles per hour)." The pulsations reveal the importance of planet-encircling waves in the Mars atmosphere. The number of waves and
their speed indicates that Mars' middle atmosphere is influenced by the
daily pattern of solar heating and disturbances from the topography of
Mars' huge volcanic mountains. These pulsating spots are the clearest
evidence that the middle atmosphere waves match those known to dominate
the layers above and below.

"MAVEN's main discoveries of atmosphere loss and climate change show the importance of these vast circulation patterns that transport atmospheric
gases around the globe and from the surface to the edge of space." said
Sonal Jain, also of LASP.

Next, the team plans to look at nightglow "sideways," instead of down
from above, using data taken by IUVS looking just above the edge of the
planet. This new perspective will be used to understand the vertical
winds and seasonal changes even more accurately.

The Martian nightglow was first observed by the SPICAM instrument on the European Space Agency's Mars Express spacecraft. However, IUVS is a next- generation instrument better able to repeatedly map out the nightside
glow, finding patterns and periodic behaviors. Many planets including
Earth have nightglow, but MAVEN is the first mission to collect so many
images of another planet's nightglow.

The research was funded by the MAVEN mission. MAVEN's principal
investigator is based at the University of Colorado's Laboratory for Atmospheric and Space Physics, Boulder, and NASA Goddard manages the
MAVEN project. NASA is exploring our Solar System and beyond, uncovering worlds, stars, and cosmic mysteries near and far with our powerful fleet
of space and ground-based missions.


========================================================================== Story Source: Materials provided by
NASA/Goddard_Space_Flight_Center. Note: Content may be edited for style
and length.


========================================================================== Related Multimedia:
* YouTube_video:_Mars_Nightglow_Animation_from_MAVEN_Observations ========================================================================== Journal Reference:
1. N. M. Schneider, Z. Milby, S. K. Jain, F. Gonza'lez‐Galindo,
E.

Royer, J.‐C. Ge'rard, A. Stiepen, J. Deighan,
A. I. F. Stewart, F.

Forget, F. Lefe`vre, S. W. Bougher. Imaging of Martian Circulation
Patterns and Atmospheric Tides Through MAVEN/IUVS Nightglow
Observations.

Journal of Geophysical Research: Space Physics, 2020; 125 (8)
DOI: 10.1029/2019JA027318 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2020/08/200806153614.htm

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