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

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

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!

If you would like to join the Weekly Space Hangout Crew, visit their site here and sign up. They’re a great team who can help you join our online discussions!

If you would like to sign up for the AstronomyCast Solar Eclipse Escape, where you can meet Fraser and Pamela, plus WSH Crew and other fans, visit our site linked above and sign up!

We record the Weekly Space Hangout every Friday at 12:00 pm Pacific / 3:00 pm Eastern. You can watch us live on Universe Today, or the Universe Today YouTube page.

NASA’s MAVEN Orbiter Discovers Solar Wind Stripped Away Mars Atmosphere Causing Radical Transformation

NASA’s Mars Atmosphere and Volatile Evolution (MAVEN) orbiter mission has determined that ancient Mars suffered drastic climate change and lost its thick atmosphere and surface bodies of potentially life giving liquid water because it lost tremendous quantities of gas to space via stripping by the solar wind, based on new findings that were announced today, Nov. 5, at a NASA media briefing and in a series of scientific publications.

The process of Mars dramatic transformation from a more Earth-like world to its barren state today started about 4.2 Billion years ago as the shielding effect of the global magnetic field was lost as the planets internal dynamo cooled, Bruce Jakosky, MAVEN principal investigator at the Laboratory for Atmospheric and Space Physics (LASP) at the University of Colorado, Boulder, told Universe Today.

The radical transformation of ancient Mars from a warm world with significant bodies of standing water that could have supported life, to its current state as a cold, arid and desert-like world that’s rather inhospitable to life was caused by the loss of most the planet’s atmosphere as powerful streams of solar wind particles crashed into it and stripped it away due to the loss of the protective magnetic field as the planets core cooled.

“We think that the early magnetic field that Mars had would have protected the planet from direct impact by the solar wind and would have kept it from stripping gas off,” Jakosky told me.

“So it would have been the turn off of the magnetic field, that would have allowed the turn on of stripping of the atmosphere by the solar wind.”

“The evidence suggests that the magnetic field disappeared about 4.2 Billion years ago.”

The period of abundant surface water actively carving the Martian geology lasted until about 3.7 Billion years ago. The loss of the atmosphere by stripping of the solar wind took place from about 4.2 to 3.7 Billion years ago.

Billions of years ago, Mars was a very different world. Liquid water flowed in long rivers that emptied into lakes and shallow seas. A thick atmosphere blanketed the planet and kept it warm.  Credit: NASA
Billions of years ago, Mars was a very different world. Liquid water flowed in long rivers that emptied into lakes and shallow seas. A thick atmosphere blanketed the planet and kept it warm. Credit: NASA

With the release of today’s results, the MAVEN science team has accomplished the primary goal of the mission, which was to determine how and why Mars lost its early, thick atmosphere and water over the past four billion years. The atmosphere is composed mostly of carbon dioxide.

Since water is a prerequisite for life as we know it, determining its fate and longevity on Mars is crucial for determining the habitability of the Red Planet and its potential for supporting martian microbes, past of present if they ever existed.

“The NASA Mars exploration program has been focused on finding water,” said Michael Meyer, lead scientist for the Mars Exploration Program at NASA Headquarters.

“Water is the prime ingredient needed for life. It is a major factor in the climate and for shaping geology. And it is a critical resource for future human exploration.”

NASA’s goal is to send humans on a ‘Journey to Mars’ during the 2030s.

This NASA video shows a visualization of the solar wind striking Mars:

Video caption: Created using data from NASA’s Mars Atmosphere and Volatile Evolution (MAVEN) mission, this visualization shows how the solar wind strips ions from the Mars’ upper atmosphere into space. Credits: NASA-GSFC/CU Boulder LASP/University of Iowa

MAVEN arrived in orbit at Mars just over one year ago on Sept. 21, 2014.

The $671 Million MAVEN spacecraft’s goal is to study Mars tenuous upper atmosphere in detail for the very first time by any spacecraft and to explore the mechanisms of how the planet lost its atmosphere and life giving water over billions of years as well as determine the rate of atmospheric loss.

The new MAVEN data have enabled researchers to measure the rate of Mars atmospheric loss of gas to space via the action of solar wind stripping as well as the erosional effect of solar storms.

Based on measurements from MAVEN’s suite of nine state-of-the-art scientific instruments, the solar wind is stripping away gas at a rate of about 100 grams (equivalent to roughly 1/4 pound) every second today, in the form of carbon dioxide and oxygen, said David Brain, MAVEN co-investigator at LASP.

“Most of the stripping [of the Martian atmosphere] by the solar wind at Mars was thought to have taken place very early in the history of the solar system when the sun was much more active and when the solar wind was more intense. So today the rate of loss at Mars is low,” Jakosky said at the briefing.

“Today’s Mars is a cold dry desert-like environment. The atmosphere is thin and it’s not capable of sustaining liquid water at the surface today, it would freeze or evaporate very quickly. However when we look at ancient Mars we see a different type of surface, one that had valleys that looked like they were carved by water and lakes that were standing for long periods of time. We see an environment that was much more able to support liquid water.”

The MAVEN results were published today in nearly four dozen scientific papers in the Nov. 5 issues of the journals Science and Geophysical Research Letters.

I asked Jakosky; How much gas would have been lost from ancient Mars and what is the rough estimate for the ancient rate of loss to arrive at Mars thin atmosphere today?

“For the amount of gas that we think you would have to have been removed – let me start with the current Mars atmosphere which has a thickness of 6 millibars, that’s just under 1% as thick as the Earth’s atmosphere,” Jakosky replied.

“So we think you would have to remove an amount of gas that is about equivalent to what’s in Earth’s atmosphere today.”

“So the rate would have to have been a factor of about 100 to 1000 times higher, than today’s loss of 100 grams per second in order to have removed the gas early in that time period, which is consistent with what the models have predicted that the loss rate would have been back then in early history.”

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
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

What is the solar wind and how does it strip away the atmosphere?

“The solar wind is a stream of particles, mainly protons and electrons, flowing from the sun’s atmosphere at a speed of about one million miles per hour. The magnetic field carried by the solar wind as it flows past Mars can generate an electric field, much as a turbine on Earth can be used to generate electricity. This electric field accelerates electrically charged gas atoms, called ions, in Mars’ upper atmosphere and shoots them into space,” according to a NASA description.

MAVEN is NASA’s next Mars orbiter and is due to blastoff on Nov. 18 from Cape Canaveral, Florida. It will study the evolution of the Red Planet’s atmosphere and climate. Universe Today visited MAVEN inside the clean room at the Kennedy Space Center.  With solar panels unfurled, this is exactly how MAVEN looks when flying through space and circling Mars.  Credit: Ken Kremer/kenkremer.com
MAVEN is NASA’s next Mars orbiter and is due to blastoff on Nov. 18 from Cape Canaveral, Florida. It will study the evolution of the Red Planet’s atmosphere and climate. Universe Today visited MAVEN inside the clean room at the Kennedy Space Center. With solar panels unfurled, this is exactly how MAVEN looks when flying through space and circling Mars. Credit: Ken Kremer/kenkremer.com

MAVEN is just now completing its primary mission and starts the extended mission phase on Nov. 16.

The 5,400 pound MAVEN probe carries nine sensors in three instrument suites to study why and exactly when did Mars undergo the radical climatic transformation.

MAVEN’s observations will be tied in with NASA’s ongoing Curiosity and Opportunity surface roving missions as well as MRO and Mars Odyssey to provide the most complete picture of the fourth rock from the sun that humanity has ever had.

MAVEN thundered to space on Nov. 18, 2013 following a flawless blastoff from Cape Canaveral Air Force Station’s Space Launch Complex 41 atop a powerful United Launch Alliance Atlas V rocket.

Stay tuned here for Ken’s continuing Earth and planetary science and human spaceflight news.

Ken Kremer

NASA’s MAVEN Mars orbiter, chief scientist Prof. Bruce Jakosky of CU-Boulder and Ken Kremer of Universe Today inside the clean room at the Kennedy Space Center on Sept. 27, 2013. MAVEN launched to Mars on Nov. 18, 2013 from Florida. Credit: Ken Kremer/kenkremer.com
NASA’s MAVEN Mars orbiter, chief scientist Prof. Bruce Jakosky of CU-Boulder and Ken Kremer of Universe Today inside the clean room at the Kennedy Space Center on Sept. 27, 2013. MAVEN launched to Mars on Nov. 18, 2013 from Florida. Credit: Ken Kremer/kenkremer.com

Does the Red Planet Have Green Auroras?

Martian auroras will never best the visual splendor of those we see on Earth, but have no doubt. The Red Planet still has what it takes to throw an auroral bash. Witness the latest news from NASA’s MAVEN atmospheric probe

In December 2014, it detected widespread auroras across Mars’ northern hemisphere dubbed the “Christmas Lights”. If a similar display happened on Earth, northern lights would have been visible from as far south as Florida.

“It really is amazing,” says Nick Schneider who leads MAVEN’s Imaging Ultraviolet Spectrograph (IUVS) instrument team at the University of Colorado.  “Auroras on Mars appear to be more wide ranging than we ever imagined.”

A beautiful curtain of rays spread across the northern sky just last night (May 12) as seen from Duluth, Minn. Aurora colors on Earth are caused by the excitation of nitrogen and oxygen atoms from high-speed particles from the solar wind. Oxygen is responsible for most of the aurora's greens and reds. Credit: Bob King
A beautiful curtain of auroral rays spreads across the northern sky last night (May 12) as seen from Duluth, Minn. Aurora colors on Earth are caused by the excitation of nitrogen and oxygen atoms by high-speed particles in the solar wind. Oxygen in particular is responsible for most of the aurora’s greens and reds. Credit: Bob King

Study the map and you’ll see the purple arcs extend to south of 30° north latitude. So what would Martian auroras look like to the human eye? Would we see an arcade of nested arcs if we faced east or west from 30°N? Well, er, yes, if you could see into the ultraviolet end of the spectrum. Mars’ atmosphere is composed mostly of carbon dioxide, so most of the auroral emissions occur when high speed solar wind particles ionize CO2 molecules and carbon monoxide to produce UV light. Perhaps properly suited-up bees, which can see ultraviolet, would be abuzz at the sight.

High-speed particles from the Sun, mostly electrons, strike oxygen and nitrogen atoms in Earth's upper atmosphere. Credit: NASA
High-speed particles from the Sun, mostly electrons, strike oxygen and nitrogen atoms in Earth’s upper atmosphere. As they return to their “relaxed” state, they emit light in characteristic colors. Credit: NASA

That’s not the end of the story however. Martian air does contain 0.13% oxygen, the element that puts the green and red in Earth’s auroras. The “Christmas Lights” penetrated deeply into Mars’ atmosphere, reaching an altitude of just 62 miles (100 km) above its surface. Here, the air is relatively thicker and richer in oxygen than higher up, so maybe, just maybe Christmas came in green wrapping.

Mars has magnetized rocks in its crust that create localized, patchy magnetic fields (left). In the illustration at right, we see how those fields extend into space above the rocks. At their tops, auroras can form. Credit: NASA
Mars has magnetized rocks in its crust that create localized, patchy magnetic fields (left). In the illustration at right, we see how those fields extend into space above the rocks. At their “peaks”, auroras can form. Credit: NASA

Nick Schneider, who leads MAVEN’s Imaging Ultraviolet Spectrograph (IUVS) instrument team, isn’t certain but thinks it’s possible that a diffuse green glow could appear in Mars’ sky during particularly energetic solar storms.

A magnetosphere is that area of space, around a planet, that is controlled by the planet's magnetic field. The shape of the Earth's magnetosphere is the direct result of being blasted by solar wind, compressed on its sunward side and elongated on the night-side, the magnetotail. Credits: NASA
Earth’s  magnetosphere, an area of space that’s controlled by the planet’s magnetic field, guides solar wind electrons and protons along magnetic field lines into the atmosphere in the polar regions  to create auroras. The planet’s field is created by electric currents generated in its outer nickel-iron core.
Credits: NASA

While the solar wind produces auroras at both Earth and Mars, they originate in radically different ways. At Earth, we’re ensconced in a protective planet-wide magnetic field. Charged particles from the Sun are guided to the Earth’s poles by following a multi-lane freeway of  global magnetic field lines.  Mars has no such organized, planet-wide field. Instead, there are many locally magnetic regions. Particles arriving from the Sun go where the magnetism takes them.

“The particles seem to precipitate into the atmosphere anywhere they want,” says Schneider. “Magnetic fields in the solar wind drape across Mars, even into the atmosphere, and the charged particles just follow those field lines down into the atmosphere.”

Maybe one day, NASA or one of the other space agencies will send a lander with a camera that can shoot long time exposures at night. We’ll call it the “Go Green” initiative.

Surprise – Mars Has Auroras Too!

Just a day after skywatchers at mid- to upper-latitudes around the world were treated to a particularly energetic display of auroras on the night of March 17 as a result of an intense geomagnetic storm, researchers announced findings from NASA’s MAVEN mission of auroral action observed on Mars – although in energetic ultraviolet wavelengths rather than visible light.

Detected by MAVEN’s Imaging Ultraviolet Spectrograph (IUVS) instrument over five days before Dec. 25, 2014, the ultraviolet auroras have been nicknamed Mars’ “Christmas lights.” They were observed across the planet’s mid-northern latitudes and are the result of Mars’ atmosphere interacting directly with the solar wind.

Map of the UV aurora detected on Mars in Dec. 2014 (University of Colorado)
Map of the UV aurora detected on Mars in Dec. 2014 (University of Colorado)

While auroras on Earth typically occur at altitudes of 80 to 300 kilometers (50 to 200 miles) and occasionally even higher, Mars’ atmospheric displays were found to be much lower, indicating higher levels of energy.

“What’s especially surprising about the aurora we saw is how deep in the atmosphere it occurs – much deeper than at Earth or elsewhere on Mars,” said Arnaud Stiepen, IUVS team member at the University of Colorado. “The electrons producing it must be really energetic.”

To a human observer on Mars the light show probably wouldn’t be very dramatic, though. Without abundant amounts of oxygen and nitrogen in its thin atmosphere a Martian aurora would be a dim blue glow at best, if not out of the visible spectrum entirely.

This isn’t the first time auroras have been spotted on Mars; observations with ESA’s Mars Express in 2004 were actually the first detections of the phenomenon on the Red Planet. Made with the spacecraft’s SPICAM ultraviolet spectrometer, the observations showed that Mars’ auroras are unlike those found anywhere else in the Solar System in that they are generated by particle interactions with very localized magnetic field emissions, rather than a globally-generated one (like Earth’s).

(So no, it’s not a total surprise… but it’s still very cool!)

In addition to auroras MAVEN also detected diffuse but widespread dust clouds located surprisingly high in the Martian atmosphere. It’s not yet understood what process is delivering dust so high – 150-300 kilometers up (93-186 miles) – or if it is a permanent or temporary feature.

Read more in the MAVEN news release here.

Source: NASA and Nature

 

 

Universe Today’s Top 10 Space Stories of 2014

It seems a lot of the space stories of this year involve spacecraft making journeys: bouncing across a comet, or making their way to Mars. Private companies also figure prominently, both in terms of successes and prominent failures.

These are Universe Today’s picks for the top space stories of the year. Disagree? Think we forgot something? Let us know in the comments.

10. End of Venus Express

Artist's impression of Venus Express performing aerobreaking maneuvers in the planet's atmosphere in June and July 2014. Credit: ESA–C. Carreau
Artist’s impression of Venus Express performing aerobreaking maneuvers in the planet’s atmosphere in June and July 2014. Credit: ESA–C. Carreau

This month saw the end of Venus Express’ eight-year mission at the planet, which happened after the spacecraft made a daring plunge into part of the atmosphere to learn more about its properties. The spacecraft survived the aerobraking maneuvers, but ran out of fuel after a few engine burns to raise it higher. Soon it will plunge into the atmosphere for good. But it was a productive mission overall, with discoveries ranging from a slowing rotation to mysterious “glories”.

9. Continued discoveries by Curiosity and Opportunity

1 Martian Year on Mars!  Curiosity treks to Mount Sharp in this photo mosaic view captured on Sol 669, June 24, 2014.    Navcam camera raw images stitched and colorized.   Credit: NASA/JPL-Caltech/Marco Di Lorenzo/Ken Kremer – kenkremer.com
1 Martian Year on Mars! Curiosity treks to Mount Sharp in this photo mosaic view captured on Sol 669, June 24, 2014. Navcam camera raw images stitched and colorized. Credit: NASA/JPL-Caltech/Marco Di Lorenzo/Ken Kremer – kenkremer.com

Methane? Organics? Water? Mars appears to have had these substances in abundance over its history. Continued work from the Curiosity rover — passing its second Earth year on Mars — found methane fluctuating in Gale Crater, and the first confirmed discovery of organics on the Martian surface. Opportunity is almost 11 years into its mission and battling memory problems, but the rover is still on the move (passing 41 kilometers) to an area that could be full of clay.

8. Siding Spring at Mars and the level of study of the comet by other missions at Mars

Comet Siding Spring near Mars in a composite image by the Hubble Space Telescope, capturing their positions between Oct. 18 8:06 a.m. EDT (12:06 p.m. UTC) and Oct. 19 11:17 p.m. EDT (Oct. 20, 3:17 a.m. UTC). Credit: NASA, ESA, PSI, JHU/APL, STScI/AURA
Comet Siding Spring near Mars in a composite image by the Hubble Space Telescope, capturing their positions between Oct. 18 8:06 a.m. EDT (12:06 p.m. UTC) and Oct. 19 11:17 p.m. EDT (Oct. 20, 3:17 a.m. UTC). Credit: NASA, ESA, PSI, JHU/APL, STScI/AURA

We had a rare opportunity to watch a comet make a grazing pass by Mars, not close enough to pose significant danger to spacecraft, but definitely close enough to affect its atmosphere! Siding Spring caught everyone’s attention throughout the year, and did not disappoint. The numerous spacecraft at the Red Planet caught glimpses, including from the surface and from orbit. It likely created a meteor shower and could alter the Martian atmosphere forever.

7. Kepler K2

Illustration of the Kepler spacecraft (NASA/Kepler mission/Wendy Stenzel)
Illustration of the Kepler spacecraft (NASA/Kepler mission/Wendy Stenzel)

The Kepler space telescope lost the second of its four pointing devices last year, requiring a major rethink for the veteran planet hunter. The solution was a new mission called K2 that uses the pressure of the Sun to maintain the spacecraft’s direction, although it has to flip every 83 days or so to a new location to avoid the star’s glare. It’s not as precise as before, but with the mission approved we now know for sure K2 can locate exoplanets. The first confirmed one is a super-Earth.

6. MAVEN at Mars

An artist's conception of MAVEN orbiting Mars. Image Credit: NASA / Goddard Space Flight Center
An artist’s conception of MAVEN orbiting Mars. Image Credit: NASA / Goddard Space Flight Center

Where did the Martian atmosphere go? Why was it so thick in the past, allowing water to flow on the surface, and so thin right now? The prevailing theory is that the Sun’s pressure on the Martian atmosphere pushed lighter isotopes (such as that of hydrogen) away from the planet, leaving heavier isotopes behind. NASA is now investigating this in more detail with MAVEN (Mars Atmosphere and Volatile Evolution), which arrived at the planet this fall.

5. India’s MOM

Artist's impression of India’s Mars Orbiter Mission (MOM). Credit ISRO
Artist’s impression of India’s Mars Orbiter Mission (MOM). Credit ISRO

India made history this year as only the third entity to successfully reach the Red Planet (after the United States and Europe). While updates from the Mars Orbiter Mission have been slow in recent weeks, we know for sure that it observed Siding Spring at Mars and it has been diligently taking pictures of the Red Planet, such as this one of the Solar System’s largest volcano and a huge canyon on Mars.

4. Accidents by Virgin and Orbital

NTSB investigators are seen making their initial inspection of debris from the Virgin Galactic SpaceShipTwo. The debris field stresses over a fiver mile range in the Mojave desert. (Credit: Getty Images)
NTSB investigators are seen making their initial inspection of debris from the Virgin Galactic SpaceShipTwo. The debris field stresses over a fiver mile range in the Mojave desert. (Credit: Getty Images)

In one sobering week in October, the dangers of space travel were again made clear after incidents affected Virgin Galactic and Orbital Sciences. Virgin lost a pilot and seriously injured another when something went seriously awry during a flight test. Investigators have so far determined that the re-entry system turned on prematurely, but more details are being determined. Orbital meanwhile suffered the catastrophic loss of one of its Antares rockets, perhaps due to Soviet-era-designed engines, but the company is looking at other ways to fulfill its NASA contractual obligations to send cargo to the International Space Station.

3. SpaceX rocket landing attempts

The Falcon 9 rocket with landing legs in SpaceX’s hangar at Cape Canaveral, Fl, preparing to launch Dragon to the space station this Sunday March 30.  Credit: SpaceX
The Falcon 9 rocket with landing legs in SpaceX’s hangar at Cape Canaveral, Fl, preparing to launch Dragon to the space station this Sunday March 30. Credit: SpaceX

SpaceX is attempting a daunting technological feat, which is bringing back its rocket first stages for re-use. The company is hoping that this will cut down on the costs of launch in the long term, but this technological innovation will take some time. The Falcon 9 rocket stage that made it back to the ocean in July was deemed a success, although the force of the landing broke it apart. Next, SpaceX is trying to place its rocket on an ocean platform.

2. Orion flight

Orion Service Module fairing separation. Credit: NASA TV
Orion Service Module fairing separation. Credit: NASA TV

NASA’s spacecraft for deep space exploration (Orion) successfully finished its first major uncrewed test this month, when it rode into orbit, made a high-speed re-entry and successfully splashed down in the ocean. But it’s going to be a while before Orion flies again, likely in 2017 or even 2018. NASA hopes to put a crew on this spacecraft type in the 2020s, potentially for trips to the Moon, an asteroid or (more distantly) Mars.

1. Rosetta

New Rosetta mission findings do not exclude comets as a source of water in and on the Earth's crust but does indicate comets were a minor contribution. A four-image mosaic comprises images taken by Rosetta’s navigation camera on 7 December from a distance of 19.7 km from the centre of Comet 67P/Churyumov-Gerasimenko. (Credit: ESA/Rosetta/Navcam Imager)
New Rosetta mission findings do not exclude comets as a source of water in and on the Earth’s crust but does indicate comets were a minor contribution. A four-image mosaic comprises images taken by Rosetta’s navigation camera on 7 December from a distance of 19.7 km from the centre of Comet 67P/Churyumov-Gerasimenko. (Credit: ESA/Rosetta/Navcam Imager)

It’s been an exciting year for the Rosetta mission. First it woke up from a lengthy hibernation, then it discovered that Comet 67P/Churyumov-Gerasimenko looks a bit like a rubber duckie, and then it got up close and released the Philae lander. The soft touchdown did not go as planned, to say the least, as the spacecraft bounced for two hours and then came to rest in a spot without a lot of sunlight. While Philae hibernates and controllers hope it wakes up again in a few months, however, science results are already showing intriguing things. For example, water delivered to Earth likely came mostly from other sources than comets.

Orbital Sciences Selects ULA’s Atlas V to Launch Next Cygnus Cargo Ship to Station

A United Launch Alliance Altas V 401 rocket like that shown here will launch the next Orbital Sciences Cygnus cargo ship to the space station in place of the Antares rocket. NASA’s Mars-bound MAVEN spacecraft launches atop Atlas V booster at 1:28 p.m. EST from Space Launch Complex 41 at Cape Canaveral Air Force Station on Nov. 18, 2013. Image taken from the roof of the Vehicle Assembly Building (VAB) at NASA’s Kennedy Space Center. Credit: Ken Kremer/kenkremer.com
More photos added[/caption]

Following the catastrophic Oct. 28 failure of an Orbital Sciences Corporation Antares rocket on a critical resupply mission to the space station for NASA, the company is seeking to quickly make up the loss to NASA by announcing the selection of the venerable Atlas V rocket built by United Launch Alliance to launch Orbital’s next Cygnus cargo ship to the orbital science lab.

Orbital and ULA signed a contract to launch at least one, and up to two, Cygnus cargo missions to the International Space Station (ISS) under NASA’s Commercial Resupply Services (CRS) program.

The first Cygnus mission would liftoff sometime late in the fourth quarter of 2015 aboard an Atlas V 401 vehicle from Space Launch Complex 41 (SLC-41) at Cape Canaveral Air Force Station in Florida.

Given that ULA’s full launch manifest was fairly full for the next 18 months, Orbital is fortunate to have arranged one or two available launch slots so quickly in the wake of the Antares launch disaster.

“Orbital is pleased to partner with ULA for these important cargo missions to the International Space Station,” said Frank Culbertson, Orbital executive vice president and general manager of its Advanced Programs Group.

“ULA’s ability to integrate and launch missions on relatively short notice demonstrates ULA’s manifest flexibility and responsiveness to customer launch needs.”

Antares doomed descent to incendiary destruction after first stage propulsion system of Orbital Sciences’ rocket exploded moments after blastoff from NASA’s Wallops Flight Facility, VA, on Oct. 28, 2014. Credit: Ken Kremer – kenkremer.com
Antares’ doomed descent to incendiary destruction after the first stage propulsion system of Orbital Sciences’ rocket exploded moments after blastoff from NASA’s Wallops Flight Facility, VA, on Oct. 28, 2014. Credit: Ken Kremer – kenkremer.com

Orbital also stated that there will be “no cost increase to the space agency” by utilizing the Atlas V as an interim launcher.

If necessary, a second Cygnus would be launched by the Atlas V in 2016.

The 401 version of the Atlas uses a 4 meter diameter payload fairing, no solid rocket boosters strapped on to the first stage, and a single-engine Centaur upper stage.

This Cygnus launched atop Antares on Jan. 9 and docked on Jan. 12   Cygnus pressurized cargo module – side view – during exclusive visit by  Ken Kremer/Universe Today to observe prelaunch processing by Orbital Sciences at NASA Wallops, VA. ISS astronauts will open this hatch to unload 2780 pounds of cargo.  Docking mechanism hooks and latches to ISS at left. Credit: Ken Kremer – kenkremer.com
This Cygnus launched atop Antares on Jan. 9 and docked on Jan. 12 Cygnus pressurized cargo module – side view – during exclusive visit by Ken Kremer/Universe Today to observe prelaunch processing by Orbital Sciences at NASA Wallops, VA. ISS astronauts will open this hatch to unload 2780 pounds of cargo. Docking mechanism hooks and latches to ISS at left. Credit: Ken Kremer – kenkremer.com

Orbital had been evaluating at least three different potential launch providers.

Observers speculated that in addition to ULA, the other possibilities included a SpaceX Falcon 9 or a rocket from the European Space Agency at the Guiana Space Center.

“We could not be more honored that Orbital selected ULA to launch its Cygnus spacecraft,” said Jim Sponnick, vice president, Atlas and Delta Programs.

“This mission was awarded in a highly competitive environment, and we look forward to continuing ULA’s long history of providing reliable, cost-effective launch services for customers.”

The Orbital-3, or Orb-3, mission that ended in disaster on Oct. 28 was to be the third of eight cargo resupply missions to the ISS through 2016 under the NASA Commercial Resupply Services (CRS) contract award valued at $1.9 Billion.

The highly anticipated launch of the Antares rocket on Oct 28 suddenly went awry when one of the Soviet-era first stage engines unexpectedly exploded and cascaded into a spectacular aerial fireball just above the launch pad at NASA’s Wallops Flight Facility on the Orb-3 mission to the ISS.

Read my earlier eyewitness accounts at Universe Today.

First stage propulsion system at base of Orbital Sciences Antares rocket appears to explode moments after blastoff from NASA’s Wallops Flight Facility, VA, on Oct. 28, 2014, at 6:22 p.m. Credit: Ken Kremer – kenkremer.com
First stage propulsion system at base of Orbital Sciences Antares rocket appears to explode moments after blastoff from NASA’s Wallops Flight Facility, VA, on Oct. 28, 2014, at 6:22 p.m. Credit: Ken Kremer – kenkremer.com

Orbital was awarded a $1.9 Billion contract with NASA under the CRS program to deliver 20,000 kilograms of research experiments, crew provisions, spare parts, and hardware for the eight ISS flights.

In choosing the Atlas V with a greater lift capacity compared to Antares, Orbital will also be able to significantly increase the cargo mass loaded inside the Cygnus by about 35%.

This may allow Orbital to meet its overall space station payload obligation to NASA in 7 total flights vs. the originally planned 8.

The venerable Atlas V rocket is one of the most reliable and well built rockets in the world.

NASA’s Mars bound MAVEN spacecraft atop Atlas V booster rolls out to Launch Complex 41 at Cape Canaveral Air Force Station on Nov. 16, 2013. Credit: Ken Kremer/kenkremer.com
The next Orbital Sciences Cygnus cargo ship to the space station will launch inside a 4m diameter payload firing, as shown here, on a United Launch Alliance Altas V 401 rocket used for NASA’s MAVEN. NASA’s Mars-bound MAVEN spacecraft atop Atlas V booster rolls out to Launch Complex 41 at Cape Canaveral Air Force Station on Nov. 16, 2013. Credit: Ken Kremer/kenkremer.com

Indeed the Atlas V has been entrusted to launch many high value missions for NASA and the Defense Department – such as MAVEN, Curiosity, JUNO, TDRSS, and the X-37 B.

MAVEN launched on a similar 401 configuration being planned for Cygnus.

The two-stage Atlas rocket is also being man-rated right now to launch humans to low Earth orbit in the near future.

Orbital is still in the process of deciding on a new first stage propulsion system for Antares’ return to flight planned for perhaps sometime in 2016.

Watch here for Ken’s ongoing reporting about Antares and NASA Wallops.

Stay tuned here for Ken’s continuing Earth and Planetary science and human spaceflight news.

Ken Kremer

Orbital Sciences technicians at work on two AJ26 first stage engines at the base of an Antares rocket during exclusive visit by Ken Kremer/Universe Today at NASA Wallaps.  These engines powered the successful Antares  liftoff on Jan. 9, 2014 at NASA Wallops, Virginia bound for the ISS.  Credit: Ken Kremer - kenkremer.com
Soviet era NK-33 engines refurbished as the AJ26 exactly like pictured here probably caused Antares’ rocket failure on Oct. 28, 2014. Orbital Sciences technicians at work on two AJ26 first stage engines at the base of an Antares rocket during exclusive visit by Ken Kremer/Universe Today at NASA Wallaps. These engines powered the successful Antares liftoff on Jan. 9, 2014 at NASA Wallops, Virginia bound for the ISS. Credit: Ken Kremer – kenkremer.com

‘Meteoric Smoke’: Comet Siding Spring Could Alter Mars Chemistry Permanently

Feeling lucky? Events such as the Comet Siding Spring approach by Mars in October only happen about once every eight million years, according to NASA.

And after we were treated to spectacular views from the agency’s spacecraft (see Curiosity and Opportunity and MAVEN, for example), we now have fresh pictures this month from an Indian mission. Also, NASA has released science results suggesting that the chemistry of Mars’ atmosphere could be changed forever from the close encounter.

“The image in the center shows a streak … radiating out of the comet’s nucleus (out of frame), possibly indicating the jet from [the] comet’s nucleus,” the Indian Science Research Organisation wrote of the above image sequence on its Facebook mission page.

“Usually jets represent outgassing activity from [the] vents of the comet-nucleus, releasing dust and ice crystals. The outgassing activity gradually increases as the comet moves closer to the Sun.”

Artist view of the comet passing closest to Mars this Sunday. At the time, the Mars orbiters from the U.S., Europe and India will be huddled on the opposite side of the planet to avoid possible impacts from comet dust. Credit: NASA
Artist view of the comet passing closest to Mars this Sunday. At the time, the Mars orbiters from the U.S., Europe and India will be huddled on the opposite side of the planet to avoid possible impacts from comet dust. Credit: NASA

The comet’s dust likely produced a meteor shower or meteor storm when particles from it crashed into the upper atmosphere, which “literally changed the chemistry,” added Jim Green, director of NASA’s planetary science division, in a recent discussion highlighted on an agency blog.

The agency says the dust created vaporized metals, which will eventually transform to dust or “meteoric smoke.” MAVEN (which stands for Mars Atmosphere and Volatile EvolutioN) will be monitoring the long-term effects. Possible results include high-altitude clouds or at the most extreme, maybe permanently altering what the chemistry of the atmosphere is. Not a bad thing for a mission to study shortly after it arrived at Mars.

You can view more science results from NASA’s studies of Siding Spring in this recent Universe Today story from Bob King, which talks in more detail about the meteor shower, new layers in the Mars atmosphere and the omnipresent dust.