An ultraviolet view of the Red Planet
NASA has released a number of globalultraviolet images of Mars, constructed from data harvested by theagency's MAVEN spacecraft. The data will help scientists tounderstand the processes at play in the tenuous Martian atmosphere,including the means by which the Red Planet's enormous volcanoes become sheathed in cloud.
The Mars Atmosphere and VolatileEvolutioN (MAVEN) probe was launched in November 2013 with a missionto explore the Martian atmosphere. The data used in the new imageswas collected by the orbiter's Imaging Ultraviolet Spectrograph(IUVS) instrument, which was designed to characterize the RedPlanet's upper atmosphere and ionosphere.
In the newly released images, theultraviolet light, which would ordinarily be invisible to human eyes,has been presented in false color.
Since its arrival around Mars inSeptember 2014, MAVEN has been hard at work. Part of the new image releasetakes the form of an incredibly detailed ultraviolet view of theMartian south polar region, as seen by the orbiter on July 10, 2016.The data used to create the scene was harvested as the southernhemisphere of the Red Planet experienced its spring season.
By observing the UV signature of thepolar regions as the southern hemisphere progressed through spring,NASA saw a build-up of ozone, indicated in magenta. The build-up comes about because water, which normally destroys ozone, freezes out of the atmosphere in winter. Even though spring would bring warmer temperatures to the pole and with it, ozone-busting water, the fact that ozone remained suggests that wind patterns werelargely preventing water vapor from returning to the pole.
Also represented in the new release arethe first-ever images of a Martian "nightglow" – a phenomenonthat causes the side of a planet facing away from the Sun to gentlyglow with ultraviolet light. Whilst the phenomenon is named for thenight, the process responsible for creating the glow begins on theday side of the planet, where ultraviolet light from the Sun breaksdown molecules of carbon dioxide and nitrogen into their componentatoms.
These atoms are then transferred to thenight side of the planet thanks to strong, high-altitude winds. The newly deposited nitrogen and oxygen atomsthen sink further down into the atmosphere, where they collide toform nitric oxide. As the atoms combine to create new molecules,excess energy is released in the form of ultraviolet light, which canbe picked up by an orbiting spacecraft's spectrometer.
By observing this ultraviolet glow,MAVEN's science team was able to infer that splotches and linespresent in the "nightglow" data point to irregularities in thecirculation patterns of high-altitude winds. The new images shouldallow scientists a greater understanding of vital wind patterns thatdictate the nature of the Martian atmosphere between 37 – 62 miles(60 – 100 km) above the Red Planet's barren surface.
Alongside the static images, NASA hasreleased a brief nine-second video documenting seven hours ofultraviolet light data. Terrain on the left side of the planet in thevideo is experiencing morning conditions, while land on the right isexperiencing afternoon, prior to slipping into the night side of theplanet.
Three of Mars' massive volcanoes areprominently displayed in the video. The monstrous landmarks areeasily discernible in the ultraviolet data by the white blotches ofcloud that gather around their steep peaks. As thedisk of the planet rotates, Olympus Mons, the tallest volcano on theRed Planet slips into view, appearing as a dark smudge.
As the Martian day progresses towardsevening, the white clouds situated above the volcanoes growexponentially. This continues until the clouds shrouding the three volcanoes combine into a single vast cloudspanning roughly 1,000 miles (1,609km). Collecting data on cloud formations such as those seen in thevideo is valuable, as it helps scientists to understand the dynamicbehavior of the Martian atmosphere, on daily, and even seasonaltimescales.
Scroll down to view the NASA videocreated from data collected by MAVEN on July 9 – 10 2016.