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Are you Friggatriskaidekaphobic (suffering from the irrational fear of Friday the 13th)?
Supremely defying any hints of superstition, the fearless team directing MAVEN—NASA’s next orbiter bound for the Red Planet—celebrated this Friday the 13th of June as a noteworthy mission milestone marking just 100 days to the crucial Mars Orbital Insertion (MOI) engine firing scheduled for Sept. 21, 2014.
“Happy Friday the 13th, everyone!” the team excitedly announced.
See above NASA’s cool new mission poster released for the agency’s newest Mars orbiter, the Mars Atmosphere and Volatile Evolution (MAVEN), which will investigate the planet’s thin upper atmosphere and begin solving the riddles of Mars’ climate mysteries, atmospheric loss, and habitability.
“Where did the water go and where did the carbon dioxide go from the early atmosphere? What were the mechanisms?” asks Bruce Jakosky, MAVEN’s Principal Investigator from the University of Colorado at Boulder.
“The spacecraft remains on schedule for Mars orbit insertion on September 21, 2014,” the MAVEN team reports.
As of today, June 15, it’s T-Minus 98 days and counting to MOI!
On June 12, MAVEN was 103,999,786 km (64,622,471 miles) from Earth, with an Earth-centered velocity of 17.0 km/s (10.5 mi/s or 38,000 mph) and a Sun-centered velocity of 23.2 km/s (14.4 mi/s or 51,800 mph).
“I’m delighted that we’re operating in space so well,” Jakosky told me. “We’re on our way!”
Each day it gets 1.4 million km farther away from Earth.
MAVEN has now traveled over 515,271,717 km (320,174,387 miles) on its heliocentric transfer path. The spacecraft is currently less than 26,700,000 km (16,500,000 miles) from Mars.
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BEGIN_DESC
MAVEN Mars approach
END_DESC
BEGIN_ENVIRONMENT
System Sol
Date MJD 56920
END_ENVIRONMENT
BEGIN_FOCUS
Ship Maven
END_FOCUS
BEGIN_CAMERA
TARGET Maven
MODE Extern
POS 14.34 140.22 23.26
TRACKMODE TargetRelative
FOV 40.00
END_CAMERA
BEGIN_HUD
TYPE Surface
END_HUD
BEGIN_MFD Left
TYPE Surface
SPDMODE 1
END_MFD
BEGIN_MFD Right
TYPE Orbit
PROJ Ship
FRAME Equator
ALT
REF Earth
END_MFD
BEGIN_SHIPS
Maven:maven/maven
STATUS Orbiting Mars
RPOS 575101025.881842 15759550.5336757 134181905.738636
RVEL -3125.0182541922 -48.2915828940409 -723.908664298885
AROT 13.47 -22.38 -16.77
RCSMODE 2
AFCMODE 7
PRPLEVEL 0:0.949959
NAVFREQ 0 0
SOLP 3 1.0000 2 1.0000
APPA 0 0.0000 0 0.0000
KROT 0
END
END_SHIPS
MAVEN Spacecraft Returns First Mars Observations
NASA’s Mars Atmosphere and Volatile Evolution (MAVEN) spacecraft has obtained its first observations of the extended upper atmosphere surrounding Mars.
The Imaging Ultraviolet Spectrograph (IUVS) instrument obtained these false-color images eight hours after the successful completion of Mars orbit insertion by the spacecraft at 10:24 p.m. EDT Sunday, Sept. 21, after a 10-month journey.
The image shows the planet from an altitude of 36,500 km in three ultraviolet wavelength bands. Blue shows the ultraviolet light from the sun scattered from atomic hydrogen gas in an extended cloud that goes to thousands of kilometers above the planet’s surface. Green shows a different wavelength of ultraviolet light that is primarily sunlight reflected off of atomic oxygen, showing the smaller oxygen cloud. Red shows ultraviolet sunlight reflected from the planet’s surface; the bright spot in the lower right is light reflected either from polar ice or clouds.
The oxygen gas is held close to the planet by Mars’ gravity, while lighter hydrogen gas is present to higher altitudes and extends past the edges of the image. These gases derive from the breakdown of water and carbon dioxide in Mars’ atmosphere. Over the course of its one-Earth-year primary science mission, MAVEN observations like these will be used to determine the loss rate of hydrogen and oxygen from the Martian atmosphere. These observations will allow us to determine the amount of water that has escaped from the planet over time.
MAVEN is the first spacecraft dedicated to exploring the tenuous upper atmosphere of Mars.
Image credit: Laboratory for Atmospheric and Space Physics, University of Colorado; NASA
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Auroras flare up when energetic particles plunge into a planet’s atmosphere, bombarding gases and making them glow. While electrons generally cause this natural phenomenon, sometime protons can elicit the same response, although it’s more rare. Now, the MAVEN team has learned that protons were doing at Mars the same thing as electrons usually do at Earth—create aurora. This is especially true when the Sun ejects a particularly strong pulse of protons, which are hydrogen atoms stripped of their lone electrons by intense heat. The Sun ejects protons at speeds up to two million miles per hour (more than 3 million kilometers per hour) in an erratic flow called the solar wind.
The MAVEN (Mars Atmosphere and Volatile Evolution mission) team was studying Mars’ atmosphere with the Imaging UltraViolet Spectrograph (IUVS), and observed that on occasion, the ultraviolet light coming from hydrogen gas in Mars' upper atmosphere would mysteriously brighten for a few hours. They then noticed that the brightening events occurred when another MAVEN instrument, the Solar Wind Ion Analyzer (SWIA), measured enhanced solar wind protons.
But two puzzles make this type of aurora seem impossible at first glance: how did these protons get past the planet’s “bow shock,” a magnetic obstacle which normally diverts the solar wind’s charged particles around the planet? And how could the protons give off light, since atoms need electrons to do so?
“The answer was thievery,” said Justin Deighan, of the Laboratory for Atmospheric and Space Physics at the University of Colorado, Boulder, lead author of a paper on this research appearing July 23 in Nature Astronomy. “As they approach Mars, the protons coming in with the solar wind transform into neutral atoms by stealing electrons from the outer edge of the huge cloud of hydrogen surrounding the planet. The bow shock can only divert charged particles, so these neutral atoms continue right on through.” When those high-speed incoming atoms hit the atmosphere, some of their energy was emitted as ultraviolet light, which is invisible to the human eye but detectable to instruments like the IUVS on MAVEN. In fact, one incoming atom can collide with molecules in the atmosphere hundreds of times before it slows down, giving off a slew of ultraviolet photons.
“The Martian proton auroras are more than a light show,” said Jasper Halekas of the University of Iowa, responsible for the SWIA instrument. “They reveal that the solar wind is not completely diverted around Mars, by showing how solar wind protons can sneak past the bow shock and impact the atmosphere, depositing energy and even enhancing the hydrogen content there.”
Proton auroras do occur at Earth, but not as often as at Mars. One key difference is Earth’s strong magnetic field, which diverts the solar wind away from Earth to a much greater degree than at Mars. On Earth, proton auroras only occur in very small regions near the poles, whereas at Mars they can happen everywhere.
However, proton auroras could be common on Venus and on Saturn’s moon Titan. Like Mars, these two worlds lack their own magnetic fields, and have lots of hydrogen in their upper atmospheres—with plenty of electrons to share. Looking further, it’s likely that many planets orbiting other stars have the same favorable conditions, and would be likely to have proton auroras too.
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