NASA’s MAVEN Witnessed Auroras as Multiple Solar Storms Crashed into Mars

Artist’s illustration of NASA’s MAVEN spacecraft orbiting Mars. (Credit: NASA)

After orbiting Mars for eight long years, NASA’s Mars Atmosphere and Volatile EvolutioN (MAVEN) spacecraft observed an extraordinary duo of auroras around the Red Planet that resulted from solar storms emanating from the Sun only a few days earlier on August 27. This observation is extraordinary since Mars lacks a global magnetic field so the solar flares must have been very powerful for MAVEN to detect them.

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A New Map Shows how Solar Winds Rain Down Everywhere on Mars

In a joint effort between NASA’s MAVEN spacecraft and the United Arab Emirates’ Emirates Mars mission (EMM), scientists have observed an uncommonly chaotic interaction between the solar wind and Mars’ upper atmosphere, creating a unique ultraviolet aurora. The phenomenon represents an unusual occurrence in Martian space weather, and scientists are excited to take advantage of future collaborations between spacecraft to keep an eye out for repeat events.

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40 Telescopes Watched the Sun as the Parker Solar Probe Made its Most Recent Flyby

Sometimes in space, even when you’re millions of kilometers from anything, you’re still being watched.  Or at least that’s the case for the Parker Solar Probe, which completed the 11th perihelion of its 24 perihelion journey on February 25th.  While the probe was speeding past the Sun, it was being watched by over 40 space and ground-based telescopes.

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Dust Storms on Mars Continue to Make the Planet Drier

NASA’s Mars Atmosphere and Volatile EvolutioN (MAVEN) spacecraft celebrated one Earth year in orbit around Mars on Sept. 21, 2015. MAVEN was launched to Mars on Nov. 18, 2013 from Cape Canaveral Air Force Station in Florida and successfully entered Mars’ orbit on Sept. 21, 2014. Credit: NASA

Despite decades of exploration and study, Mars still has its fair share of mysteries. In particular, scientists are still trying to ascertain what happened to the water that once flowed on Mars’ surface. Unfortunately, billions of years ago, the Martian atmosphere began to be stripped away by the solar wind, which also resulted in the loss of its surface water over time – although it was not entirely clear where it went and what mechanisms were involved.

To address this, a team of scientists recently consulted data obtained by three orbiter missions studying the Martian atmosphere. In the process, they found evidence that the smaller regional dust storms that happen almost annually on Mars are making the planet drier over time. These findings suggest that storms are a major driving force behind the evolution of Mars’ atmosphere and its transition to the freezing and desiccated place we know today.

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What Could We Learn From a Mission to Phobos?

Phobos. From where did it arise or arrive? Is it dry or wet? Should we flyby or sample and return? Should it be Boots or Bots? (Photos: NASA, Illus.:T.Reyes)

According to new research that appeared in the scientific journal Nature Geoscience, the larger of Mars’ two moons (Phobos) has an orbit that takes it through a stream of charged particles (ions) that flow from the Red Planet’s atmosphere. This process has been taking place for billions of years as the planet slowly lost its atmosphere, effectively establishing a record of Martian climate change on Phobos’ surface.

This research has provided yet another incentive for landing a mission on Phobos, something that has never been done successfully. In essence, this mission could gather sample data that would allow scientists to study this record more closely. In the process, they would be able to learn a great deal more about how Mars went from being a warmer world with liquid water to the extremely arid and cold environment it is today.

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The Martian Sky Pulses in Ultraviolet Every Night

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. Credits: NASA/MAVEN/Goddard Space Flight Center/CU/LASP

There’s a surprising phenomenon taking place in Mars’ atmosphere: during the spring and fall seasons on the Red Planet, large areas of the sky pulse in ultraviolet light, exactly three times every night.  

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Mars Doesn’t Have Much of a Magnetosphere, But Here’s a Map

This image is from a scientific visualization of the electric currents around Mars. Electric currents (blue and red arrows) envelop Mars in a nested, double-loop structure that wraps continuously around the planet from its day side to its night side. These current loops distort the solar wind magnetic field (not pictured), which drapes around Mars to create an induced magnetosphere around the planet. In the process, the currents electrically connect Mars’ upper atmosphere and the induced magnetosphere to the solar wind, transferring electric and magnetic energy generated at the boundary of the induced magnetosphere (faint inner paraboloid) and at the solar wind bow shock (faint outer paraboloid). Credits: NASA/Goddard/MAVEN/CU Boulder/SVS/Cindy Starr

Even though Earthling scientists are studying Mars intently, it’s still a mysterious place.

One of the striking things about Mars is all of the evidence, clearly visible on its surface, that it harbored liquid water. Now, all that water is gone, and in fact, liquid water couldn’t survive on the surface of the Red Planet. Not as the planet is now, anyway.

But it could harbour water in the past. What happened?

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Carl Sagan’s Theory Of Early Mars Warming Gets New Attention

Credit and copyright: ESA/DLR/FU Berlin (G. Neukum)

Ah, the good old days. ESA’s Mars Express imaged Reull Vallis, a river-like structure believed to have formed when running water flowed in the distant Martian past, cuts a steep-sided channel on its way towards the floor of the Hellas basin. A thicker atmosphere that included methane and hydrogen in addition to carbon dioxide may have allowed liquid water to flow on Mars at different times in the past according to a new study. Credit and copyright: ESA/DLR/FU Berlin (G. Neukum)

Water. It’s always about the water when it comes to sizing up a planet’s potential to support life. Mars may possess some liquid water in the form of occasional salty flows down crater walls,  but most appears to be locked up in polar ice or hidden deep underground. Set a cup of the stuff out on a sunny Martian day today and depending on conditions, it could quickly freeze or simply bubble away to vapor in the planet’s ultra-thin atmosphere.

These rounded pebbles got their shapes after polished in a long-ago river in Gale Crater. They were discovered by Curiosity rover at the Hottah site. Credit: NASA/JPL-Caltech

Evidence of abundant liquid water in former flooded plains and sinuous river beds can be found nearly everywhere on Mars. NASA’s Curiosity rover has found mineral deposits that only form in liquid water and pebbles rounded by an ancient stream that once burbled across the floor of Gale Crater. And therein lies the paradox.  Water appears to have gushed willy-nilly across the Red Planet 3 to 4 billion years ago, so what’s up today?

Blame Mars’ wimpy atmosphere. Thicker, juicier air and the increase in atmospheric pressure that comes with it would keep the water in that cup stable. A thicker atmosphere would also seal in the heat, helping to keep the planet warm enough for liquid water to pool and flow.

Different ideas have been proposed to explain the putative thinning of the air including the loss of the planet’s magnetic field, which serves as a defense against the solar wind.

This figure shows a cross-section of the planet Mars revealing an inner, high density core buried deep within the interior. Magnetic field lines are drawn in blue, showing the global scale magnetic field associated with a dynamic core. Mars must have had such a field long ago, but today it’s not evident. Perhaps the energy source that powered the early dynamo shut down. Credit: NASA/JPL/GSFC

Convection currents within its molten nickel-iron core likely generated Mars’ original magnetic defenses. But sometime early in the planet’s history the currents stopped either because the core cooled or was disrupted by asteroid impacts. Without a churning core, the magnetic field withered, allowing the solar wind to strip away the atmosphere, molecule by molecule.


Solar wind eats away the Martian atmosphere

Measurements from NASA’s current MAVEN mission indicate that the solar wind strips away gas at a rate of about 100 grams (equivalent to roughly 1/4 pound) every second. “Like the theft of a few coins from a cash register every day, the loss becomes significant over time,” said Bruce Jakosky, MAVEN principal investigator.

This graph shows the percent amount of the five most abundant gases in the atmosphere of Mars, as measured by the  Sample Analysis at Mars (SAM) instrument suite on the Curiosity rover in October 2012. The season was early spring in Mars’ southern hemisphere. Credit: NASA/JPL-Caltech, SAM/GSFC

Researchers from the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS) suggest a different, less cut-and-dried scenario. Based on their studies, early Mars may have been warmed now and again by a powerful greenhouse effect. In a paper published in Geophysical Research Letters, researchers found that interactions between methane, carbon dioxide and hydrogen in the early Martian atmosphere may have created warm periods when the planet could support liquid water on its surface.

The team first considered the effects of CO2, an obvious choice since it comprises 95% of Mars’ present day atmosphere and famously traps heat. But when you take into account that the Sun shone 30% fainter 4 billion years ago compared to today, CO2  alone couldn’t cut it.

“You can do climate calculations where you add CO2 and build up to hundreds of times the present day atmospheric pressure on Mars, and you still never get to temperatures that are even close to the melting point,” said Robin Wordsworth, assistant professor of environmental science and engineering at SEAS, and first author of the paper.

NASA’s Cassini spacecraft looks toward the night side of Saturn’s largest moon and sees sunlight scattering through the periphery of Titan’s atmosphere and forming a ring of color. The breakdown of methane at Titan into hydrogen and oxygen may also have occurred on Mars. The addition of hydrogen in the company of methane and carbon dioxide would have created a powerful greenhouse gas mixture, significantly warming the planet. Credit: NASA/JPL-Caltech/Space Science Institute

Carbon dioxide isn’t the only gas capable of preventing heat from escaping into space. Methane or CH4 will do the job, too. Billions of years ago, when the planet was more geologically active, volcanoes could have tapped into deep sources of methane and released bursts of the gas into the Martian atmosphere. Similar to what happens on Saturn’s moon Titan, solar ultraviolet light would snap the molecule in two, liberating hydrogen gas in the process.

When Wordsworth and his team looked at what happens when methane, hydrogen and carbon dioxide collide and then interact with sunlight, they discovered that the combination strongly absorbed heat.

Carl Sagan, American astronomer and astronomy popularizer, first speculated that hydrogen warming could have been important on early Mars back in 1977, but this is the first time scientists have been able to calculate its greenhouse effect accurately. It is also the first time that methane has been shown to be an effective greenhouse gas on early Mars.

This awesome image of the Tharsis region of Mars taken by Mars Express shows several prominent shield volcanoes including the massive Olympus Mons (at left). Volcanoes, when they were active, could have released significant amounts of methane into Mars’ atmosphere. Click for a larger version. Credit: ESA

When you take methane into consideration, Mars may have had episodes of warmth based on geological activity associated with earthquakes and volcanoes. There have been at least three volcanic epochs during the planet’s history — 3.5 billion years ago (evidenced by lunar mare-like plains), 3 billion years ago (smaller shield volcanoes) and 1 to 2 billion years ago, when giant shield volcanoes such as Olympus Mons were active. So we have three potential methane bursts that could rejigger the atmosphere to allow for a mellower Mars.

The sheer size of Olympus Mons practically shouts massive eruptions over a long period of time. During the in-between times, hydrogen, a lightweight gas, would have continued to escape into space until replenished by the next geological upheaval.

“This research shows that the warming effects of both methane and hydrogen have been underestimated by a significant amount,” said Wordsworth. “We discovered that methane and hydrogen, and their interaction with carbon dioxide, were much better at warming early Mars than had previously been believed.”

I’m tickled that Carl Sagan walked this road 40 years ago. He always held out hope for life on Mars. Several months before he died in 1996, he recorded this:

” … maybe we’re on Mars because of the magnificent science that can be done there — the gates of the wonder world are opening in our time. Maybe we’re on Mars because we have to be, because there’s a deep nomadic impulse built into us by the evolutionary process, we come after all, from hunter gatherers, and for 99.9% of our tenure on Earth we’ve been wanderers. And, the next place to wander to, is Mars. But whatever the reason you’re on Mars is, I’m glad you’re there. And I wish I was with you.”

MAVEN Takes This Trippy, Nightglowing Photo of Mars in UV

This image of the Mars night side shows ultraviolet emission from nitric oxide. These emissions track the recombination of atomic nitrogen and oxygen produced on the dayside, and reveal the circulation patterns of the atmosphere. MAVEN's Imaging UltraViolet Spectrograph obtained this image of Mars on May 4, 2016 during late winter in Mars Southern Hemisphere. Credits: NASA/MAVEN/University of Colorado

Mars’ atmosphere is about 100 times thinner than Earth’s, but there’s still a lot going on in that wispy, carbon dioxide Martian air. The MAVEN spacecraft recently took some exceptional images of Mars using its Imaging UltraViolet Spectrograph (IUVS), revealing dynamic and previously invisible subtleties.

MAVEN took the first-ever images of nightglow on Mars. You may have seen nightglow in images of Earth taken by astronauts on the International Space Station as a dim greenish light surrounding the planet. Nightglow is produced when oxygen and nitrogen atoms collide to form nitric oxide. This is ionized by ultraviolet light from the Sun during the day, and as it travels around to the nightside of the planet, it will glow in ultraviolet.

An image of nightglow in Earth's atmosphere, taken from the International Space Station. Credit: NASA.
An image of nightglow in Earth’s atmosphere, taken from the International Space Station. Credit: NASA.

“The planet will glow as a result of this chemical reaction,” said Nick Schneider, from the Laboratory for Atmospheric and Space Physics at the University of Colorado, Boulder, speaking today at the American Astronomical Society Division for Planetary Sciences meeting. “This is a common planetary reaction that tells us about the transport of these ingredients and around the planet and show how winds circulate at high altitudes.”

MAVEN’s images show evidence of strong irregularities in Mars’ high altitude winds and circulation patterns and Schneider said these first images will lead to an improved understanding of the circulation patterns that control the behavior of the atmosphere from approximately 37 to 62 miles (about 60 to 100 kilometers) high.

MAVEN's Imaging UltraViolet Spectrograph obtained these images of rapid cloud formation on Mars on July 9-10, 2016. Mars’ prominent volcanoes, topped with white clouds, can be seen moving across the disk and show how rapidly and extensively the clouds topping the volcanoes form in the afternoon. Credits: NASA/MAVEN/University of Colorado
MAVEN’s Imaging UltraViolet Spectrograph obtained these images of rapid cloud formation on Mars on July 9-10, 2016. Mars’ prominent volcanoes, topped with white clouds, can be seen moving across the disk and show how rapidly and extensively the clouds topping the volcanoes form in the afternoon. Credits: NASA/MAVEN/University of Colorado

MAVEN’s ultraviolet images also provide insight into cloud formation and ozone in Mars atmosphere.

The images show how water ice clouds form, especially in the afternoon, over the four giant volcanoes on Mars in the Tharsis region. Cloud formation in the afternoon is a common occurrence on Earth, as convection causes water vapor to rise.

“Water ice clouds are very common on Mars and they can tell us about water inventory on the planet,” Schneider said. “In these images you can see an incredible expansion of the clouds over the course of seven hours, forming a cloud bank that must be a thousand miles across.”

He added that this is just the kind of info scientists want to be plugging in to their circulation models to study circulation and the chemistry of Mars’ atmosphere. “This is helping us advance our understanding in these areas, and we’ll be able to study it with MAVEN through full range of Mars’ seasons.”

MAVEN's Imaging UltraViolet Spectrograph obtained images of rapid cloud formation on Mars on July 9-10, 2016. The ultraviolet colors of the planet have been rendered in false color, to show what we would see with ultraviolet-sensitive eyes. Mars’ tallest volcano, Olympus Mons, appears as a prominent dark region near the top of the image, with a small white cloud at the summit that grows during the day. Three more volcanoes appear in a diagonal row, with their cloud cover (white areas near center) merging to span up to a thousand miles by the end of the day. Credits: NASA/MAVEN/University of Colorado
MAVEN’s Imaging UltraViolet Spectrograph obtained images of rapid cloud formation on Mars on July 9-10, 2016. The ultraviolet colors of the planet have been rendered in false color, to show what we would see with ultraviolet-sensitive eyes. Mars’ tallest volcano, Olympus Mons, appears as a prominent dark region near the top of the image, with a small white cloud at the summit that grows during the day. Three more volcanoes appear in a diagonal row, with their cloud cover (white areas near center) merging to span up to a thousand miles by the end of the day.
Credits: NASA/MAVEN/University of Colorado

Schneider explained that MAVEN’s unique orbit allows it to get views of the planet that other orbiters don’t have. One part of its elliptical orbit takes it high above the planet that allows for global views, but it still orbits fast enough to get multiple views as Mars rotates over the course of a day.

“We get to see daily events evolve over time because we return to that orbit every few hours,” he said.

This ultraviolet image near Mars’ South Pole was taken by MAVEN on July 10 2016 and shows the atmosphere and surface during southern spring. The white region centered on the pole is frozen carbon dioxide (dry ice) on the surface. Pockets of ice are left inside craters as the polar cap recedes in the spring, giving its edge a rough appearance. High concentrations of atmospheric ozone appear magenta in color, and the wavy edge of the enhanced ozone region highlights wind patterns around the pole. Credits: NASA/MAVEN/University of Colorado
This ultraviolet image near Mars’ South Pole was taken by MAVEN on July 10 2016 and shows the atmosphere and surface during southern spring. The white region centered on the pole is frozen carbon dioxide (dry ice) on the surface. Pockets of ice are left inside craters as the polar cap recedes in the spring, giving its edge a rough appearance. High concentrations of atmospheric ozone appear magenta in color, and the wavy edge of the enhanced ozone region highlights wind patterns around the pole.
Credits: NASA/MAVEN/University of Colorado

In addition, dayside ultraviolet imagery from the spacecraft shows how ozone amounts change over the seasons. Ozone is destroyed when water vapor is present, so ozone accumulates in the winter polar region where the water vapor has frozen out of the atmosphere. The images show ozone lasting into spring, indicating that global winds are constraining the spread of water vapor from the rest of the planet into winter polar regions.

Wave patterns in the ozone images show wind pattern, as well, helping scientists to study the chemistry and global circulation of Mars’ atmosphere.

Additional reading:
NASA

Weekly Space Hangout – October 7, 2016: James Webb: Standing on the Shoulders of Hubble

Host: Fraser Cain (@fcain)

Special Guest:
Paul Geithner, Deputy Project Manager – Technical for the James Webb Space Telescope (JWST) at NASA’s Goddard Space Flight Center.

Guests:

Kimberly Cartier ( KimberlyCartier.org / @AstroKimCartier )
Paul M. Sutter (pmsutter.com / @PaulMattSutter)
Alessondra Springmann (sondy.com / @sondy)

Their stories this week:

MAVEN’s One Year Anniversary

Giant plasma balls ejected from star

Hurricane Matthew at the space coast

Ultra-strange ultra-cool brown dwarfs

Successful test of New Shepard crew escape system

Saturday, Oct. 8 is International Observe the Moon Night!

We are now using a tool called Trello to submit and vote on stories we would like to see covered each week, and then Fraser will be selecting the stories from there. Here is the link to the Trello WSH page (http://bit.ly/WSHVote), which you can see without logging in. If you’d like to vote, just create a login and help us decide what to cover!

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