Artist's conception of a Mars Exploration Rover, which included Opportunity and Spirit. Credit: NASA
The Opportunity Mars rover is busy on its wheels as it moves towards “Marathon Valley”, a location that could include clay minerals — a sign of past water in the region. After successfully passing 41 kilometers (25.47 miles) in total driving a few weeks ago, the rover is closing out its 11th year on Mars with guided and unguided drives towards that destination.
As of late November, the latest status update available from NASA, the rover is just about a half-mile (1 kilometer) from Marathon Valley and busy collecting measurements on an interesting geologic feature en route. This followed several hundred feet of driving that took place just before.
The rover is now racing to finish its work as the Martian winter approaches. Its science activities are still being disrupted by rover difficulties, according to the Planetary Society, which follows weeks of memory problems that have plagued Opportunity through the fall. But Opportunity is still trekking despite these aging issues and transmitting raw imagery from the surface of Mars, which you can see below.
A rough panorama of the Opportunity rover’s surroundings on Mars based on three images taken on Sol 3,861 in December 2014. Credit: NASA/JPL-Caltech/Cornell Univ./Arizona State Univ. Panorama: Elizabeth HowellA shot across the Martian vista taken by the Opportunity rover on Sol 3,862 in December 2014. Credit: NASA/JPL-Caltech/Cornell Univ./Arizona State Univ.Tracks from the Opportunity Mars rover on Sol 3,861 in December 2014. Credit: NASA/JPL-Caltech/Cornell Univ./Arizona State Univ.Many of Opportunity’s photos from Mars in early December 2014, such as this one on Sol 3,860, focused on details of the terrain beneath. Credit: NASA/JPL-Caltech/Cornell Univ./Arizona State Univ.
Orion’s inaugural launch on Dec. 5, 2014 atop United Launch Alliance Delta 4 Heavy rocket at Space Launch Complex 37 (SLC-37) at Cape Canaveral Air Force Station, Florida at 7:05 a.m. Credit: Alex Polimeni/Zero-G News/AmericaSpace
Orion’s inaugural launch on Dec. 5, 2014 atop United Launch Alliance Delta 4 Heavy rocket at Space Launch Complex 37 (SLC-37) at Cape Canaveral Air Force Station, Florida at 7:05 a.m. Credit: Alex Polimeni/Zero-G News/AmericaSpace
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KENNEDY SPACE CENTER, FL – After four decades of waiting, the dawn of a new era in space exploration finally began with the dawn liftoff of NASA’s first Orion spacecraft on Friday, Dec. 5, 2014.
The picture perfect liftoff of Orion on its inaugural unmanned test flight relit the path to send humans beyond low Earth orbit for the first time since the launch of Apollo 17 on NASA’s final moon landing mission on Dec. 7, 1972.
NASA’s first Orion spacecraft blasts off at 7:05 a.m. atop United Launch Alliance Delta 4 Heavy Booster at Space Launch Complex 37 (SLC-37) at Cape Canaveral Air Force Station in Florida on Dec. 5, 2014. Launch pad remote camera view. Credit: Ken Kremer – kenkremer.com
Orion soared to space atop a United Launch Alliance Delta IV Heavy rocket at 7:05 a.m. EST from Space Launch Complex 37 (SLC-37) at Cape Canaveral Air Force Station in Florida.
Enjoy the spectacular launch photo gallery from my fellow space journalists and photographers captured from various up close locations ringing the Delta launch complex.
Tens of thousands of spectators descended upon the Kennedy Space Center to be an eyewitness to history and the new space era – and they were universally thrilled.
Orion is the first human rated spacecraft to fly beyond low Earth orbit since Apollo 17 and was built by prime contractor Lockheed Martin.
The EFT-1 mission was a complete success.
The Orion program began about a decade ago.
America’s astronauts flying aboard Orion will venture farther into deep space than ever before – beyond the Moon to Asteroids, Mars and other destinations in our Solar System starting around 2020 or 2021 on Orion’s first crewed flight atop NASA’s new monster rocket – the SLS – concurrently under development.
Watch for Ken’s ongoing Orion coverage from onsite at the Kennedy Space Center about the historic launch on Dec. 5.
Stay tuned here for Ken’s continuing Orion and Earth and planetary science and human spaceflight news.
Apollo 17 launch on Dec. 7, 1972. Credit: Julian Leek
NASA’s first Orion spacecraft blasts off at 7:05 a.m. atop United Launch Alliance Delta 4 Heavy Booster at Space Launch Complex 37 (SLC-37) at Cape Canaveral Air Force Station in Florida on Dec. 5, 2014. Credit: Ken Kremer – kenkremer.com Orion at dawn moments before liftoff on Dec. 5, 2014. Credit: Ken Kremer – kenkremer.com
The idea that Mars could have supported life at one time is the subject of ongoing debate. Image credit: NASA
Mars is currently home to a small army robotic rovers, satellites and orbiters, all of which are busy at work trying to unravel the deeper mysteries of Earth’s neighbor. These include whether or not the planet ever had liquid water on its surface, what the atmosphere once looked like, and – most importantly of all – if it ever supported life.
And while much has been learned about Martian water and its atmosphere, the all-important question of life remains unanswered. Until such time as organic molecules – considered to be the holy grail for missions like Curiosity – are found, scientists must look elsewhere to find evidence of Martian life.
According to a recent paper submitted by an international team of scientists, that evidence may have arrived on Earth three and a half years ago aboard a meteorite that fell in the Moroccan desert. Believed to have broken away from Mars 700,000 years ago, so-called Tissint meteorite has internal features that researchers say appear to be organic materials.
The paper appeared in the scientific journal Meteoritics and Planetary Sciences. In it, the research team – which includes scientists from the Swiss Federal Institute of Technology in Lausanne (EPFL) – indicate organic carbon is located inside fissures in the rock. All indications are the meteorite is Martian in origin.
“So far, there is no other theory that we find more compelling,” says Philippe Gillet, director of EPFL’s Earth and Planetary Sciences Laboratory. He and his colleagues from China, Japan and Germany performed a detailed analysis of organic carbon traces from a Martian meteorite, and have concluded that they have a very probable biological origin.
Artist’s conception of an fragment as it blasts off from Mars as a result of a meteor impact. Credit: The Planetary Society
The scientists argue that carbon could have been deposited into the fissures of the rock when it was still on Mars by the infiltration of fluid that was rich in organic matter.
If this sounds familiar, you may recall a previous Martian meteorite named ALH84001, found in the Allen Hills region in Antarctica. In 1996 NASA researchers announced they had found evidence within ALH84001 that strongly suggested primitive life may have existed on Mars more than 3.6 billion years ago. While subsequent studies of the now famous Allen Hills Meteorite shot down theories that the Mars rock held fossilized alien life, both sides continue to debate the issue.
This new research on the Tissint meteorite will likely be reviewed and rebutted, as well.
The researchers say the meteorite was likely ejected from Mars after an asteroid crashed on its surface, and fell to Earth on July 18, 2011, and fell in Morocco in view of several eyewitnesses.
Upon examination, the alien rock was found to have small fissures that were filled with carbon-containing matter. Several research teams have already shown that this component is organic in nature, but they are still debating where the carbon came from.
Chemical, microscopic and isotope analysis of the carbon material led the researchers to several possible explanations of its origin. They established characteristics that unequivocally excluded a terrestrial origin, and showed that the carbon content were deposited in the Tissint’s fissures before it left Mars.
This research challenges research proposed in 2012 that asserted that the carbon traces originated through the high-temperature crystallization of magma. According to the new study, a more likely explanation is that liquids containing organic compounds of biological origin infiltrated Tissint’s “mother” rock at low temperatures, near the Martian surface.
A piece of the Tissint meteorite that landed on Earth on July 18th, 2011. Credit: EPFL/Alain Herzog
These conclusions are supported by several intrinsic properties of the meteorite’s carbon, e.g. its ratio of carbon-13 to carbon-12. This was found to be significantly lower than the ratio of carbon-13 in the CO2 of Mars’s atmosphere, previously measured by the Phoenix and Curiosity rovers.
Moreover, the difference between these ratios corresponds perfectly with what is observed on Earth between a piece of coal – which is biological in origin – and the carbon in the atmosphere.
The researchers note that this organic matter could also have been brought to Mars when very primitive meteorites – carbonated chondrites – fell on it. However, they consider this scenario unlikely because such meteorites contain very low concentrations of organic matter.
“Insisting on certainty is unwise, particularly on such a sensitive topic,” warns Gillet. “I’m completely open to the possibility that other studies might contradict our findings. However, our conclusions are such that they will rekindle the debate as to the possible existence of biological activity on Mars – at least in the past.”
Be sure to check out these videos from EPFL News, which include an interview with Philippe Gillet, EPFL and co-author of the study:
And this video explaining the history of the Tissint meteor:
Carbon dioxide ice begins to feel the heat in the south pole region every spring. In this image of 'Inca City' taken in August 2014, you can see a few fans coming out from channels (araneiforms) that are created when pressurized gas escapes from the melting ice. Picture taken by the Mars Reconnaissance Orbiter's HiRISE camera. Credit: NASA/JPL/University of Arizona
We’ve been watching Mars with spacecraft for about 50 years, but there’s still so little we know about the Red Planet. Take this sequence of images in this post recently taken by a powerful camera on NASA’s Mars Reconnaissance Orbiter. Spring arrives in the southern hemisphere and produces a bunch of mysteries, such as gray-blue streaks you can see in a picture below.
That’s where citizen scientists can come in, according to a recent post for the University of Arizona’s High Resolution Imaging Science Experiment (HiRISE) camera that took these pictures. They’re asking people with a little spare time to sign up for Planet Four (a Zooniverse project) to look at mysterious Mars features. With amateurs and professionals working together, maybe we’ll learn more about these strange changes you see below.
On Aug. 20, 2014, Martian dust mounds are on top of the araneiforms in ‘Inca City’, as well as dark areas on the terrain showing where the ice cap in the southern hemisphere burst and sent gas and dust into the surroundings. Fans in the area are pointing in multiple directions, showing how the wind has changed. Image taken by the Mars Reconnaissance Orbiter’s HiRISE camera. Credit: NASA/JPL/University of ArizonaOn Aug. 25, 2014, more fans and blotches appear on the Martian landscape around “Inca City”, a location in the southern polar region, as the ice bursts in the springtime sun. Image obtained by the Mars Reconnaissance Orbiter’s HiRISE camera. Credit: NASA/JPL/University of ArizonaAs of Sept. 6, 2014, fans in “Inca City” in the Martian southern hemisphere are now blue-gray. Why this color appears in the spring is unknown. It could be because of particles falling into ice underneath, or gas bursting from the ice condensing and falling as frost. It could even be a combination of the two. Image taken by the Mars Reconnaissance Orbiter’s HiRISE orbiter. Credit: NASA/JPL/University of ArizonaAs spring takes hold in the southern polar region of Mars on Sept. 27, 2014, cracks are now developing in the ice at “Inca City” with multiple new dust fans appearing. Cracks develop when the ice does not have a path to easily rupture and release gas. Picture taken by the Mars Reconnaissance Orbiter’s HiRISE camera. Credit: NASA/JPL/University of Arizona
The moon appears above NASA's Orion EFT-1 spacecraft in the Kennedy Space Center area as its set to soar to space atop a Delta 4 Heavy Booster at Space Launch Complex 37 (SLC-37) at Cape Canaveral Air Force Station in Florida ahead of launch set for Dec. 4, 2014. Credit: Ken Kremer - kenkremer.com
KENNEDY SPACE CENTER, FL – This week’s appearance of the Moon over the Kennedy Space Center marks the perfect backdrop heralding the start of NASA’s determined push to send Humans to Mars by the 2030s via the agency’s new Orion crew capsule set to soar to space on its maiden test flight in less than two days.
Orion is the first human rated vehicle that can carry astronauts beyond low Earth orbit on voyages to deep space in more than 40 years.
Top managers from NASA, United Launch Alliance (ULA), and Lockheed Martin met on Tuesday, Dec. 2, and gave the “GO” to proceed toward launch after a thorough review of all systems related to the Orion capsule, rocket, and ground operation systems at the launch pad at the Launch Readiness Review (LRR), said Mark Geyer at a NASA media briefing on Dec. 2.
A new countdown display has been constructed in the place of the former analog countdown clock at the Press Site at NASA’s Kennedy Space Center in Florida for Orion’s first launch slated for Dec. 4, 2014. The display is a modern, digital LED display akin to stadium monitors. It allows television images to be shown along with numbers. Note former shuttle launch pad 39A in the background above clock. Credit: Ken Kremer – kenkremer.com
Orion is slated to lift off on a United Launch Alliance Delta IV Heavy rocket on its inaugural test flight to space on the uncrewed Exploration Flight Test-1 (EFT-1) mission at 7:05 a.m. EST on December 4, 2014, from Space Launch Complex 37 (SLC-37) at Cape Canaveral Air Force Station in Florida.
America’s astronauts flying aboard Orion will venture farther into deep space than ever before – beyond the Moon to Asteroids, Mars, and other destinations in our Solar System starting around 2020 or 2021 on Orion’s first crewed flight atop NASA’s new monster rocket – the SLS – concurrently under development.
NASA Administrator Charles Bolden officially unveils world’s largest welder to start construction of core stage of NASA’s Space Launch System (SLS) rocket at NASA Michoud Assembly Facility, New Orleans, on Sept. 12, 2014. SLS will be the world’s most powerful rocket ever built. Credit: Ken Kremer – kenkremer.com
The current weather forecast states the launch is 60 percent “GO” for favorable weather condition at the scheduled liftoff time of at 7:05 a.m. on Dec. 4, 2014.
The launch window extends for 2 hours and 39 minutes.
The two-orbit, four and a half hour Orion EFT-1 flight around Earth will lift the Orion spacecraft and its attached second stage to an orbital altitude of 3,600 miles, about 15 times higher than the International Space Station (ISS) – and farther than any human spacecraft has journeyed in 40 years.
EFT-1 will test the rocket, second stage, and jettison mechanisms, as well as avionics, attitude control, computers, and electronic systems inside the Orion spacecraft.
Orion atop Delta 4 Heavy Booster. Credit: NASA/Kim Shiflett
Then the spacecraft will carry out a high speed re-entry through the atmosphere at speeds approaching 20,000 mph and scorching temperatures near 4,000 degrees Fahrenheit to test the heat shield, before splashing down for a parachute assisted landing in the Pacific Ocean.
NASA TV will provide several hours of live Orion EFT-1 launch coverage with the new countdown clock – starting at 4:30 a.m. on Dec. 4.
Orion’s move to Launch Complex-37. Credit: Mike Killian
Watch for Ken’s ongoing Orion coverage and he’ll be onsite at KSC in the days leading up to the historic launch on Dec. 4.
Stay tuned here for Ken’s continuing Orion and Earth and planetary science and human spaceflight news.
Ken Kremer
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Learn more about Orion, SpaceX, Antares, NASA missions, and more at Ken’s upcoming outreach events:
Dec 1-5: “Orion EFT-1, SpaceX CRS-5, Antares Orb-3 launch, Curiosity Explores Mars,” Kennedy Space Center Quality Inn, Titusville, FL, evenings
Side view shows trio of Common Booster Cores (CBCs) with RS-68 engines powering the Delta IV Heavy rocket resting horizontally in ULA’s HIF processing facility at Cape Canaveral that will launch NASA’s maiden Orion on the EFT-1 mission in December 2014 from Launch Complex 37. Credit: Ken Kremer/kenkremer.com
Early Spring Dust Storms at the North Pole of Mars. Early spring typically brings dust storms to northern polar Mars. As the north polar cap begins to thaw, the temperature difference between the cold frost region and recently thawed surface results in swirling winds. The choppy dust clouds of several dust storms are visible in this mosaic of images taken by the Mars Global Surveyor spacecraft in 2002. The white polar cap is frozen carbon dioxide. (NASA/JPL/Malin Space Science Systems)
Maybe you can’t climb on a rocketship to Mars, at least yet, but at the least you can get your desire for exploration out through other means. Today, take comfort that humanity is sending 90,000 messages in the Red Planet’s direction. That’s right, the non-profit Uwingu plans to transmit these missives today around 3 p.m. EST (8 p.m. UTC).
Among the thousands of ordinary folks are a collection of celebrities: Bill Nye, the Science Guy; George Takei (“Sulu” on Star Trek) and commercial astronaut Richard Garriott, among many others.
“This is the first time messages from people on Earth have been transmitted to Mars by radio,” Uwingu stated. “The transmission, part of Uwingu’s ‘Beam Me to Mars’ project, celebrates the 50th anniversary of the 28 November 1964 launch of NASA’s Mariner 4 mission—the first successful mission to explore Mars.”
The project was initially released in the summer with the idea that it could help support struggling organizations, researchers and students who require funding for their research. The messages cost between $5 and $100, with half the money going to the Uwingu Fund for space research and education grants, and the other half for transmission costs to Mars and other needed things.
While only robots can receive those messages for now, it’s another example of transmission between the planets that we take for granted. For example, check out this stunning picture below from Mars Express, a European Space Agency mission, that was just released yesterday (Nov. 27). Every day we receive raw images back from the Red Planet that anyone can browse on the Internet. That was unimaginable in Mariner 4’s days. What will we see next?
Close-up of a trough in the huge Hellas Basin on Mars, taken by the European Space Agency’s Mars Express spacecraft and released Nov. 27, 2014. Credit: ESA/DLR/FU Berlin
Observations of Comet Siding Spring Oct. 19 by the Mars Orbiter Mission. Credit: Indian Space Research Organisation
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
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.
The Opportunity rover's view on Sol 3,839 on Nov. 11, 2014, shortly after it pushed past 41 kilometers (nearly 28.5 miles) of driving on the Red Planet. Credit: NASA/JPL-Caltech/Cornell Univ./Arizona State Univ. (panorama: Elizabeth Howell)
And even as the rover works through aging problems, the science team is still able to push it further — it just crested 41 kilometers (25.48 miles) on Sol Sol 3,836 (around Nov. 9)! Check out some recent pictures from the rover below.
The NASA machine is roaming the west edge of Endeavour Crater on its way to an area nicknamed “Marathon Valley”, which could contain clay minerals. Clays are considered a sign of water being in a region in the ancient past, which feeds into NASA’s ongoing search for habitable environments on Mars.
By the way, Opportunity is now just shy of a marathon’s worth of driving on Mars (which would be 26 miles, or 41.8 kilometers). In the meantime, we’ve collected some raw images from Opportunity to share. What new horizons will the plucky rover find next, as it draws close to its 11th anniversary on Mars in January?
The Opportunity rover continues to make tracks after passing 41 kilometers (28.5 miles) on Mars. View from Sol 3,846 in November 2014. Credit: NASA/JPL-Caltech/Cornell Univ./Arizona State Univ.Solar panels from the Opportunity Mars rover shine against the mottled ground on Sol 3,846 in November 2014. Credit: NASA/JPL-Caltech/Cornell Univ./Arizona State Univ.The wind-swept plains of Mars as seen by the Opportunity rover on Sol 3,846 in November 2014. Credit: NASA/JPL-Caltech/Cornell Univ./Arizona State Univ.A close-up of the cracked Martian ground taken by the Opportunity rover on Sol 3,846 in November 2014. Credit: NASA/JPL-Caltech/Cornell Univ./Arizona State Univ.The shadow of the Opportunity rover (bottom) lies dark against Mars ground on Sol 3,841 in November 2014. Credit: NASA/JPL-Caltech/Cornell Univ./Arizona State Univ.
The Mars Society prototype habitat in Utah conducts studies on what it would be like to live on Mars.
Credit: Mars Society MRDS
If you wanna get humans to Mars, there are so many technical hurdles in the way that it will take a lot of hard work. How to help people survive for months on a hostile surface, especially one that is bathed on radiation? And how will we keep those people safe on the long journey there and back?
NASA is greatly concerned about the radiation risk, and is asking the public for help in a new challenge as the agency measures radiation with the forthcoming uncrewed Orion test flight in December. There’s $12,000 up for grabs across at least a few awards, providing you get your ideas into the agency by Dec. 12.
“One of the major human health issues facing future space travelers venturing beyond low-Earth orbit is the hazardous effects of galactic cosmic rays (GCRs),” NASA wrote in a press release.
“Exposure to GCRs, immensely high-energy radiation that mainly originates outside the solar system, now limits mission duration to about 150 days while a mission to Mars would take approximately 500 days. These charged particles permeate the universe, and exposure to them is inevitable during space exploration.”
Orion in orbit in this artists concept. Credit: NASA
Here’s an interesting twist, too — more data will come through the Orion test flight as the next-generation spacecraft aims for a flight 3,600 miles (5,800 kilometers) above Earth’s surface. That’s so high that the vehicle will go inside a high-radiation environment called the Van Allen Belts, which only the Apollo astronauts passed through in the 1960s and 1970s en route to the Moon.
While a flight to Mars will also just graze this area briefly, scientists say the high-radiation environment will give them a sense of how Orion (and future spacecraft) perform in this kind of a zone. So the spacecraft will carry sensors on board to measure overall radiation levels as well as “hot spots” within the vehicle.
You can find out more information about the challenge, and participation details, at this link.
Credit: NASA/MRO/Rendering: James Dickson, Brown University
Though the surface of Mars is a dry, dessicated and bitterly cold place today, it is strongly believed that the planet once had rivers, streams, lakes, and flowing water on its surface. Thanks to a combination of spacecraft imagery, remote sensing techniques and surface investigations from landers and rovers, ample evidence has been assembled to support this theory.
However, it is hard to reconcile this view with the latest climate models of Mars which suggest that it should have been a perennially cold and icy place. But according to a new study, the presence of warm, flowing water may have been an episodic occurrence, something that happened for decades or centuries when the planet was warmed sufficiently by volcanic eruptions and greenhouse gases.
The study, which was conducted by scientists from Brown University and Israel’s Weizmann Institute of Science, suggests that warmth and water flow on ancient Mars were probably episodic, related to brief periods of volcanic activity that spewed tons of greenhouse-inducing sulfur dioxide gas into the atmosphere.
The work combines the effect of volcanism with the latest climate models of early Mars and suggests that periods of temperatures warm enough for water to flow likely lasted for only tens or hundreds of years at a time.
The notion that Mars had surface water predates the space age by centuries. Long before Percival Lowell observed what he thought were “canals” on the Martian surface in 1877, the polar ice caps and dark spots on the surface were being observed by astronomers who thought that they were indications of liquid water.
Curiosity found evidence of an ancient, flowing stream on Mars at a few sites, including the “Hottah” rock outcrop pictured here. Credit: NASA/JPL
But with all that’s been learned about Mars in recent years, the mystery of the planet’s ancient water has only deepened. The latest generation of climate models for early Mars suggests that the atmosphere was too thin to heat the planet enough for water to flow. Billions of years ago, the sun was also much dimmer than it is today, which further complicates this picture of a warmer early Mars.
“These new climate models that predict a cold and ice-covered world have been difficult to reconcile with the abundant evidence that water flowed across the surface to form streams and lakes,” said James W. Head, professor of earth, environmental and planetary sciences at Brown University and co-author of the new paper with Weizmann’s Itay Halevy. “This new analysis provides a mechanism for episodic periods of heating and melting of snow and ice that could have each lasted decades to centuries.”
Halevy and Head explored the idea that heating may have been linked to periodic volcanism. Many of the geological features that suggest water was flowing on the Martian surface have been dated to 3.7 billion years ago, a time when massive volcanoes are thought to have been active.
And whereas on Earth, widespread volcanism has often led to global dimming rather than warming – on account of sulfuric acid particles reflecting the sun’s rays – Head and Halevy think the effects may have been different in Mars’ dusty atmosphere.
To test this theory, they created a model of how sulfuric acid might react with the widespread dust in the Martian atmosphere. The work suggests that those sulfuric acid particles would have glommed onto dust particles and reduced their ability to reflect the sun’s rays. Meanwhile, sulfur dioxide gas would have produced enough greenhouse effect to warm the Martian equatorial region so that water could flow.
Image of the McMurdo Dry Valleys, Antarctica, acquired by Landsat 7’s Enhanced Thematic Mapper plus (ETM+) instrument. Credit: NASA/EO
Head has been doing fieldwork for years in Antarctica and thinks the climate on early Mars may have been very similar to what he has observed in the cold, desert-like.
“The average yearly temperature in the Antarctic Dry Valleys is way below freezing, but peak summer daytime temperatures can exceed the melting point of water, forming transient streams, which then refreeze,” Head said. “In a similar manner, we find that volcanism can bring the temperature on early Mars above the melting point for decades to centuries, causing episodic periods of stream and lake formation.”
As that early active volcanism on Mars ceased, so did the possibility of warmer temperatures and flowing water.
According to Head, this theory might also help in the ongoing search for signs that Mars once hosted life. If it ever did exist, this new research may offer clues as to where the fossilized remnants ended up.
“Life in Antarctica, in the form of algal mats, is very resistant to extremely cold and dry conditions and simply waits for the episodic infusion of water to ‘bloom’ and develop,” he said. “Thus, the ancient and currently dry and barren river and lake floors on Mars may harbor the remnants of similar primitive life, if it ever occurred on Mars.”
