The HI-SEAS habitat, located on Mauna Loa, Hawaii, where volunteers train to live on Mars. Credit: NASA/Hi-SEAS
When it comes time to send astronauts to Mars, those who make the journey will need to be ready for a number of challenges. In addition to enduring about six-months in space both ways, the first astronauts to explore Mars will also need to be prepared to spend months living on the surface. This will consist of long periods spent in a pressurized habitat and regular forays to the surface wearing pressure suits. Continue reading “This is the Habitat in Hawaii Helping Astronauts Preparing to Explore Mars”
Artist's impression of the Opportunity Rover, part of NASA's Mars Exploration Program. NASA/JPL-Caltech
Martian dust storms are a pretty common occurrence, and generally happen whenever the southern hemisphere is experiencing summer. Though they can begin quite suddenly, these storms typically stay contained to a local area and last only about a few weeks. However, on occasion, Martian dust storms can grow to become global phenomena, covering the entire planet.
One such storm began back in May, starting in the Arabia Terra region and then spreading to become a planet-wide dust storm within a matter of weeks. This storm caused the skies over the Perseverance Valley, where the Opportunity rover is stationed, to become darkened, forcing the rover into hibernation mode. And while no word has been heard from the rover, NASA recently indicated that the dust storm will dissipate in a matter of weeks.
The update was posted by NASA’s Mars Exploration Program, which oversees operations for the Opportunity and Curiosity rovers, as well as NASA’s three Mars orbiters (Mars Odyssey, MRO, and MAVEN) and the Insight lander (which will land on Mars in 109 days). According to NASA, the storm is beginning to end, though it may be weeks or months before the skies are clear enough for Opportunity to exit its hibernation mode.
This global map of Mars shows a growing dust storm as of June 6, 2018. The map was produced by the Mars Color Imager (MARCI) camera on NASA’s Mars Reconnaissance Orbiter spacecraft. The blue dot indicates the approximate location of Opportunity. Image Credit: NASA/JPL-Caltech/MSSS
As noted, dust storms occur on Mars when the southern hemisphere experiences summer, which coincides with the planet being closer to the Sun in its elliptical orbit. Due to increased temperatures, dust particles are lifted higher into the atmosphere, creating more wind. The resulting wind kicks up yet more dust, creating a feedback loop that NASA scientists are still trying to understand.
Since the southern polar region is pointed towards the Sun in the summer, carbon dioxide frozen in the polar cap evaporates. This has the effect of thickening the atmosphere and increasing the surface pressure, which enhances the process by helping suspend dust particles in the air. In some cases, the dust clouds can reach up to 60 km (40 mi) or more in elevation.
Planet-wide dust storms are a relatively rare occurrence on Mars, taking place every three to four Martian years (the equivalent of approximately 6 to 8 Earth years). Such storms have been viewed many times in the past by missions like Mariner 9 (1971), Viking I (1971) and the Mars Global Surveyor (2001). In 2007, a similar storm took place that darkened the skies over where Opportunity was stationed – which led to two weeks of minimal operations and no communications.
While smaller and less intense the storm that took place back in 2007, the current storm intensified to the point where it led to a level of atmospheric opacity that is much worse than the 2007 storm. In effect, the amount of dust in the atmosphere created a state of perpetual night over the rover’s location in Perseverance Valley, which forced the rover’s science team to suspend operations.
Simulated views of a darkening Martian sky blotting out the Sun from NASA’s Opportunity rover’s point of view, with the right side simulating Opportunity’s view in the global dust storm as of June 2018. Credit: NASA/JPL-Caltech/TAMU
This is due to the fact that Opportunity – unlike the Curiosity rover, which runs on nuclear-powered battery – relies on solar panels to keep its batteries charged. But beyond suspending operations, the prolonged dust storm also means that the rover might not be to keep its energy-intensive survival heaters running – which protect its batteries from the extreme cold of Mars’ atmosphere.
Luckily, NASA scientists who have been observing the global event indicated that, as of last Monday (July 23rd), more dust was falling out of the planet’s thin air than was being raised into it. This means that the global weather event has reached its decay phase, where dust-raising events either become confined to smaller areas or stop altogether.
Using its Mars Color Imager (MARCI) and Mars Climate Sounder (MCS), NASA’s Mars Reconnaissance Orbiter (MRO) also noted surface features were beginning to reappear and that temperatures in the middle atmosphere were no longer rising – which indicates less solar heating by dust. The Curiosity rover also noted a decline in dust above its position in the Gale Crater on the other side of the planet.
This is certainly good new for the Opportunity rover, though scientists expect that it will still be a few weeks or months before its solar panels can draw power again and communications can be reestablished. The last time communications took place with the rover was on June 10th, but if there’s one thing the Opportunity rover is known for, it’s endurance!
When the rover first landed on Mars on January 25th, 2004, its mission was only expected to last ninety Martian days (sols), which is the equivalent of about 92.5 Earth days. However, as of the writing of this article, the rover has endured for 14 years and 195 days, effectively exceeding its operational lifespan 55 times over. So if any rover can survive this enduring dust storm, its Opportunity!
In the meantime, multiple NASA missions are actively monitoring the storm in support of Opportunity and to learn more about the mechanics of Martian storms. By learning more about what causes these storms, and how smaller ones can merge to form global events, future robotic missions, crewed missions and (quite possibly) Martian colonists will be better prepared to deal with them.
Team Zopherus of Rogers, Arkansas, is the first-place winner in NASA’s 3D-Printed Habitat Challenge, Phase 3: Level 1 competition. Credit: NASA
If and when we decide to go to Mars (and stay there), the Martian settlers will face some serious challenges. For one, the planet is extremely cold compared to Earth, averaging at about -63 °C (-82°F), which is comparable to cold night in Antarctica. On top of that, there’s the incredibly thin atmosphere that is unbreathable to humans and terrestrial creatures. Add to that the radiation, and you begin to see why settling Mars will be difficult.
But as the saying goes, necessity is the mother of invention. And to stimulate the invention process, NASA has partnered with Bradley University of Peoria to launch the 3D-Printed Habitat Centennial Challenge competition. As part of NASA’s Centennial Challenges, which are sponsored by the Space Technology Mission Directorate, this competition recently awarded $100,000 in prize money to five teams for their design concepts.
The NASA Centennial Challenges were initiated in 2005 to directly engage the public, and produce revolutionary applications for space exploration challenges. The program offers incentive prizes to stimulate innovation in basic and applied research, technology development, and prototype demonstration. To administer the competition, Bradley University also partnered with sponsors Caterpillar, Bechtel and Brick & Mortar Ventures.
For the competition, participants were tasked with creating digital representations of the physical and functional characteristics of a Martian habitat using specialized software tools. A panel of NASA, academic and industry experts awarded the team points based on various criteria, which determined how much prize money each winning team got. Out of 18 submissions from all over the world, 5 teams were selected.
In order of how much prize money they were awarded, the winning teams were:
Team Zopherus of Rogers, Arkansas – $20,957.95
AI. SpaceFactory of New York – $20,957.24
Kahn-Yates of Jackson, Mississippi – $20,622.74
SEArch+/Apis Cor of New York – $19,580.97
Northwestern University of Evanston, Illinois – $17,881.10
The design competition emphasizes all the challenges that building a life-supporting habitat on Mars would entail, which includes the sheer distances involved and the differences in atmosphere and landscapes. In short, the teams needed to create habitats that would be insulated and air-tight and could also be built using local materials (aka. in-situ resource utilization).
The competition began in 2014 and has been structured in three phases. For Phase 1, the Design Competition (which was completed in 2015 with $50,000 prize purse), the teams were required to submit a rendering of their proposed habitat. Phase 2, the Structural Member Competition, focused on material technologies and required teams to create structural components. This phase was completed in 2017 with a $1.1 million prize purse.
For Phase 3, the On-Site Habitat Competition – which is the current phase of the competition – competitors were tasked with fabricated sub-scale versions of their habitats. This phase has five levels of competition, which consist of two virtual levels and three construction levels. For the former, the teams were tasked with using Building Information Modeling (BIM) software to design a habitat that combines all the structural requirements and systems it must contain.
For the construction levels, the teams will be required to autonomously fabricate 3D-printed elements of the habitat, culminating with a one-third-scale printed habitat for the final level. By the end of this phase, teams will be awarded prize money from a $2 million purse. As Monsi Roman, the program manager for NASA’s Centennial Challenges, said in a recent NASA press statement:
“We are thrilled to see the success of this diverse group of teams that have approached this competition in their own unique styles. They are not just designing structures, they are designing habitats that will allow our space explorers to live and work on other planets. We are excited to see their designs come to life as the competition moves forward.”
The winning entries included team Zorphues’ concept for a modular habitat that was inspired by biological structures here on Earth. The building-process begins with a lander (which is also a mobile print factory) reaching the surface and scanning the environment to find a good “print area”. It then walks over this area and deploys rovers to gather materials, then seals to the ground to provide a pressurized print environment.
The main module is then assembled using pre-fabricated components (like airlocks, windows, atmospheric control, toilets, sinks, etc), and the structure is printed around it. The printer then walks itself to an adjacent location, and prints another module using the same method. In time, a number of habitats are connected to the main module that provide spaces for living, recreation, food production, scientific studies, and other activities.
For their concept, the second place team (Team AI. SpaceFactory) selected a vertically-oriented cylinder as the most efficient shape for their Marsha habitat. According to the team, this design is not only the ideal pressure environment, but also maximizes the amount of usable space, allows for the structure to be vertically-divided based on activities, is well-suited to 3-D printing and takes up less surface space.
The team’s also designed their habitat to deal with temperature changes on Mars, which are significant. Their solution was to design the entire structure as a flanged shell that moves on sliding bearings at its foundation in response to temperature changes. The structure is also a double shell, with the outer (pressure) shell separate from the inner habitat entirely. This optimizes air flow and allows for light to filters in to the entire habitat.
Next up is the Khan-Yates habitat, which the team designed to be specifically-suited to withstand dust storms and harsh climates on the Red Planet. This coral-like dome consists of a lander that would set down in the equatorial region, then print a foundation and footing layer using local materials. The print arm would then transition vertically to begin printing the shell and the floors.
The outer shell is studded with windows that allow for a well-lit environment, the outer shell is separate from the core, and the shape of the structure is designed to ensure that dust storms flow around the structure. In fourth place was SEArch+/Apis Cor’s Mars X house, a habitat designed to provide maximum radiation protection while also ensuring natural light and connections to the Martian landscape.
The habitat is constructed by mobile robotic printers, which are deployed from a Hercules Single-Stage Reusable Lander. The design is inspired by Nordic architecture, and uses “light scoops” and floor-level viewing apertures to ensure that sunlight in the northern latitudes makes it into the interior. The two outer (and overlapping) shells house the living areas, which consist of two inflatable spaces with transparent CO2 inflated window pockets.
Fifth place went to the team from Northwestern University for their Martian 3Design habitat, which consists of an inner sphere closed-shell and an outer parabolic dome. According to the team, this habitat provides protection from the Martian elements through three design features. The first is the internal shape of the structure, which consists of a circular foundation, an inflatable pressure vessel that serves as the main living area, and the outer shell.
The second feature is the entryway system, which extend from opposite ends of the structure and serves as entrances and exits and could provide junctions with future pods. The third feature is the cross-beams that are the structural backbone of the dome and are optimized for pressure-loading under Martian gravity and atmospheric conditions, and provide continuous protection from radiation and the elements.
The interior layout is based on the NASA Hawai’i Space Exploration Analog and Simulation (HI-SEAS) habitat, and is divided between “wet areas” and “dry areas”. These areas are placed on opposite sides of the habitat to optimize the use of resources by concentrated in them on one side (rather than have them running throughout that habitat), and space is also divided by a central, retractable wall that separates the interior into public and private areas.
Together, these concepts embody the aims of the 3D-Printed Habitat Centennial Challenge, which is to harness the talents of citizen inventors to develop the technologies necessary to build sustainable shelters that will one-day allow humans to live on the Moon, Mars and beyond. As Lex Akers, dean of the Caterpillar College of Engineering and Technology at Bradley University, said of the competition:
“We are encouraging a wide range of people to come up with innovative designs for how they envision a habitat on Mars. The virtual levels allow teams from high schools, universities and businesses that might not have access to large 3D printers to still be a part of the competition because they can team up with those who do have access to such machinery for the final level of the competition.”
Carrying on in the tradition of the Centennial Prizes, NASA is seeking public engagement with this competition to promote interest in space exploration and address future challenges. It also seeks to leverage new technologies in order to solve the many engineering, technical and logistical problems presented by space travel. Someday, if and when human beings are living on the Moon, Mars, and other locations in the Solar System, the habitats they call home could very well be the work of students, citizen inventors and space enthusiasts.
For more information on the 3-D Pinrted Habitat Challenge, check out the competition web page.
Artist's conception of a terraformed Mars. Credit: Ittiz/Wikimedia Commons
For almost a century now, the concept of terraforming has been explored at length by both science fiction writers and scientists alike. Much like setting foot on another planet or traveling to the nearest star, the idea of altering an uninhabitable planet to make it suitable for humans is a dream many hope to see accomplished someday. At present, much of that hope and speculation is aimed at our neighboring planet, Mars.
But is it actually possible to terraform Mars using our current technology? According to a new NASA-sponsored study by a pair of scientists who have worked on many NASA missions, the answer is no. Put simply, they argue that there is not enough carbon dioxide gas (CO2) that could practically be put back into Mars’ atmosphere in order to warm Mars, a crucial step in any proposed terraforming process.
The study, titled “Inventory of CO2 available for terraforming Mars“, recently appeared in the journal Nature Astronomy. The study was conducted by Bruce Jakosky – a professor of geological sciences and the associate director of the Laboratory for Atmospheric and Space Physics (LASP) at the University of Colorado, Boulder – and Christopher S. Edwards, an assistant professor of planetary science at Northern Arizona University and the leader of the Edwards Research Group.
The study was supported in part by NASA through the Mars Atmospheric and Volatile EvolutioN (MAVEN) and Mars Odyssey THEMIS (Thermal Emission Imaging System) projects. Whereas Professor Jakosky was the Principal Investigator on the MAVEN mission, Professor Edwards is a participating scientist on the Mars Science Laboratory Curiosity Rover (MSL), and worked on the Mars Odyssey THEMIS mission (among other Mars missions).
As we explored in a previous article, “How Do We Terraform Mars?“, many methods have been suggested for turning the Red Planet green. Many of these methods call for warming the surface in order to melt the polar ice caps, which would release an abundant amount of CO2 to thicken the atmosphere and trigger a greenhouse effect. This would in turn cause additional CO2 to be released from the soil and minerals, reinforcing the cycle further.
According to many proposals, this would be followed by the introduction of photosynthetic organisms such as cyanobacteria, which would slowly convert the atmospheric CO2 into oxygen gas and elemental carbon. This very method was suggested in a 1976 NASA study, titled “On the Habitability of Mars: An Approach to Planetary Ecosynthesis“. Since that time, multiple studies and even student teams have proposed using cyanobacteria to terraform Mars.
However, after conducting their analysis, Professors Jakosky and Edwards concluded that triggering a greenhouse effect on Mars would not be as simple as all that. For the sake of their study, Jakosky and Edwards relied on about 20 years of data accumulated by multiple spacecraft observations of Mars. As Edwards indicated in a recent NASA press release:
“These data have provided substantial new information on the history of easily vaporized (volatile) materials like CO2 and H2O on the planet, the abundance of volatiles locked up on and below the surface, and the loss of gas from the atmosphere to space.”
Scientists were able to gauge the rate of water loss on Mars by measuring the ratio of water and HDO from today and 4.3 billion years ago. Credit: Kevin Gill
To determine if Mars had enough gases for a greenhouse effect, Jakosky and Edwards analyzed data from NASA’s Mars Reconnaissance Orbiter (MRO) and Mars Odyssey spacecraft to determine the abundance of carbon-bearing minerals in Martian soil and CO2 in polar ice caps. They they used data from NASA’s MAVEN mission to determine the loss of the Martian atmosphere to space. As Prof. Jakosky explained:
“Carbon dioxide (CO2) and water vapor (H2O) are the only greenhouse gases that are likely to be present on Mars in sufficient abundance to provide any significant greenhouse warming… Our results suggest that there is not enough CO2 remaining on Mars to provide significant greenhouse warming were the gas to be put into the atmosphere; in addition, most of the CO2 gas is not accessible and could not be readily mobilized. As a result, terraforming Mars is not possible using present-day technology.”
Although Mars has significant quantities of water ice, previous analyses have shown that water vapor would not be able to sustain a greenhouse effect by itself. In essence, the planet is too cold and the atmosphere too thin for the water to remain in a vaporous or liquid state for very long. According to the team, this means that significant warming would need to take place involving CO2 first.
However, Mars atmospheric pressure averages at about 0.636 kPA, which is the equivalent of about 0.6% of Earth’s air pressure at sea level. Since Mars is also roughly 52% further away from the Sun than Earth (1.523 AUs compared to 1 AU), researchers estimate that a CO2 pressure similar to Earth’s total atmospheric pressure would be needed to raise temperatures enough to allow for water to exist in a liquid state.
Artist’s rendering of a solar storm hitting Mars and stripping ions from the planet’s upper atmosphere. Credits: NASA/GSFC
According to the team’s analysis, melting the polar ice caps (which is the most accessible source of carbon dioxide) would only contribute enough CO2 to double the Martian atmospheric pressure to 1.2% that of Earth’s. Another source is the dust particles in Martian soil, which the researchers estimate would provide up to 4% of the needed pressure. Other possible sources of carbon dioxide are those that are locked in mineral deposits and water-ice molecule structures known as “clathrates”.
However, using the recent NASA spacecraft observations of mineral deposits, Jakosky and Edwards estimate that these would likely yield less than 5% of the require pressure each. What’s more, accessing even the closest minerals to the surface would require significant strip mining, and accessing all the CO2 attached to dust particles would require strip mining the entire planet to a depth of around 90 meters (100 yards).
Accessing carbon-bearing minerals deep in the Martian crust could be a possible solution, but the depth of these deposits is currently unknown. In addition, recovering them with current technology would be incredibly expensive and energy-intensive, making extraction highly impractical. Other methods have been suggested, however, which include importing flourine-based compounds and volatiles like ammonia.
The former was proposed in 1984 by James Lovelock and Michael Allaby in their book, The Greening of Mars. In it, Lovelock and Allaby described how Mars could be warmed by importing chlorofluorocarbons (CFCs) to trigger global warming. While very effective at triggering a greenhouse effect, these compounds are short-lived and would need to be introduced in significant amounts (hence why the team did not consider them).
NASA’s MAVEN spacecraft is depicted in orbit around an artistic rendition of planet Mars, which is shown in transition from its ancient, water-covered past, to the cold, dry, dusty world that it has become today. Credit: NASA
The idea of importing volatiles like ammonia is an even more time-honored concept, and was proposed by Dandridge M. Cole and Donald Cox in their 1964 book, “Islands in Space: The Challenge of the Planetoids, the Pioneering Work“. Here, Cole and Cox indicated how ammonia ices could be transported from the outer Solar System (in the form of iceteroids and comets) and then impacted on the surface.
However, Jakosky and Edwards’ calculations reveal that many thousands of these icy objects would be required, and the sheer distance involved in transporting them make this an impractical solution using today’s technology. Last, but not least, the team considered how atmospheric loss could be prevented (which could be done using a magnetic shield). This would allow for the atmosphere to build up naturally due to outgassing and geologic activity.
Unfortunately, the team estimates that at the current rate at which outgassing occurs, it would take about 10 million years just to double Mars’ current atmosphere. In the end, it appears that any effort to terraform Mars will have to wait for the development of future technologies and more practical methods.
These technologies would most likely involve more cost-effective means for conducting deep-space missions, like nuclear-thermal or nuclear-electric propulsion. The establishment of permanent outposts on Mars would also be an important first step, which could be dedicated to thickening the atmosphere by producing greenhouse gases – something humans have already proven to be very good at here on Earth!
Project Nomad, a concept for terraforming Mars using mobile, factory-skyscrapers from the 2013 Skyscraper Competition. Credit: evolo.com/Antonio Ares Sainz, Joaquin Rodriguez Nuñez, Konstantino Tousidonis Rial
There’s also the possibility of importing methane gas from the outer Solar System, another super-greenhouse gas, which is also indigenous to Mars. While it constitutes only a tiny percentage of the atmosphere, significant plumes have been detected in the past during the summer months. This includes the “tenfold spike” detected by the Curiosity rover in 2014, which pointed to a subterranean source. If these sources could be mined, methane gas might not even need to be imported.
For some time, scientists have known that Mars was not always the cold, dry, and inhospitable place that it is today. As evidenced by the presence of dry riverbeds and mineral deposits that only form in the presence of liquid water, scientists have concluded that billions of years ago, Mars was a warmer, wetter place. However, between 4.2 and 3.7 billion years ago, Mars’ atmosphere was slowly stripped away by solar wind.
This discovery has led to renewed interest in the colonizing and terraforming of Mars. And while transforming the Red Planet to make it suitable for human needs may not be doable in the near-future, it may be possible to get the process started in just a few decades’ time. It may not happen in our lifetime, but that does not mean that the dream of one-day making “Earth’s Twin” truly live up to its name won’t come true.
Mosaic image of "Wdowiak Ridge", taken by NASA's Mars Exploration Rover Opportunity on Sept. 17th, 2014. Credit: NASA/JPL
For generations, many have dreamed about the day when it would be possible to set foot on Mars – aka. “Earth’s Twin” planet. And in the past few years, multiple orbiters, landers and rovers have revealed evidence of past water on Mars, not to mention the possibility that water still exists underground. These findings have fueled the desire to send crewed missions to Mars, not to mention proposals to establish a colony there.
However, this enthusiasm may seem a little misguided when you consider all the challenges the Martian environment presents. In addition to it being very cold and subject to a lot of radiation, the surface of Mars today is also extremely dry. According to a new study led by researchers from NASA’s Ames Research Center, Martian soil is roughly 1000 times drier than some of the driest regions on Earth.
The Atacama Desert in northern Chile. Credit: NASA/Frank Tavares
For the sake of their study, the research team sought to determine if microorganisms can survive under the types of conditions present on Mars. To answer this question, the team traveled to the the Atacama Desert in Chile, a 1000 km (620 mi) strip of land on South America’s west coast. With an average rainfall of just 1 to 3 mm (0.04 to 0.12 in) a year, the Atacama desert is known as the driest nonpolar place in the world.
However, the Atacama desert is not uniformly dry, and experiences different levels of precipitation depending on the latitude. From the southern end to the northern end, annual precipitation shifts from a few millimeters of rain per year to only a few millimeters of rain per decade. This environment provides an opportunity to search for life at decreasing levels of precipitation, thus allowing researchers to place constraints on microorganism survivability.
It is at the northern end of the desert (in what is known as the Antofagasta region) where conditions become most Mars-like. Here, the average annual rainfall is just 1 mm a year, which has made it a popular destination for scientists looking to simulate a Martian environment. In addition to seeing if microbes could survive in these dry conditions, the team also sought to determine if they were capable of growth and reproduction.
As Mary Beth Wilhelm – an astrobiologist at the Georgia Institute of Technology, NASA’s Ames Research Center, and lead author of the new study – explained in a recent NASA press release:
“On Earth, we find evidence of microbial life everywhere. However, in extreme environments, it’s important to know whether a microbe is dormant and just barely surviving, or really alive and well… By learning if and how microbes stay alive in extremely dry regions on Earth, we hope to better understand if Mars once had microbial life and whether it could have survived until today.”
Researchers collect samples from the surface of the Atacama Desert in Chile, going a few centimeters into the ground. Credits: NASA Ames Research Center
After collecting soil samples from across the Atacama Desert and brought them back to their lab at Ames, the research team began performing tests to see if their microorganism samples showed any indication of stress markers. These are a key way in which life can be shown to be growing, since organisms in a dormant state (i.e. that are just surviving) show no signs of stress markers.
Specifically, they looked for changes in the lipid structure of the cells outer membranes, which typically become more rigid in response to stress. What they found was that in the less dry parts of the Atacama Desert, this stress marker was present; but strangely, these same markers were missing in the driest regions of the desert where microbes would be more stressed.
Based on these and other results, the team concluded that there is a transition line for microorganisms in environments like the Atacama Desert. On one side of this line, the presence of minute amounts of water is enough for organisms to still be able to grow. On the other side, the environment is so dry that organisms can survive but will not grow and reproduce.
The team was also able to find evidence of microbes that had been dead in the Atacama soil samples for at least 10,000 years. They were able to determine this by examining the amino acids of the microbes, which are the building blocks of proteins, and examining the rate at which their structure changed. This find was rather surprising, seeing as how it is extremely rare that the remnant of ancient life be found on the surface of Earth.
This artist’s concept depicts NASA’s Mars 2020 rover exploring Mars. Credit: NASA
Given that Mars is 1,000 times drier than even the driest parts of Atacama, these results were not encouraging news for those hoping that microbial life will still be found there. However, the fact that the remnants of past microbial life were found in the driest areas of Chile’s desert – which would have existed when conditions were wetter and were well-preserved – is very good news when it comes to the search for past life on Mars.
Essentially, if microbial life did exist on Mars back when it was a warmer, wetter environment, traces of that ancient life might still exist. As Wilhelm explained:
“Before we go to Mars, we can use the Atacama like a natural laboratory and, based on our results, adjust our expectations for what we might find when we get there. Knowing the surface of Mars today might be too dry for life to grow, but that traces of microbes can last for thousands of years helps us design better instruments to not only search for life on and under the planet’s surface, but to try and unlock the secrets of its distant past.”
In the future, missions like NASA’s Mars 2020 rover will be seeking to procure samples of Martian soil. If NASA’s proposed “Journey to Mars” takes place by the 2030s as planned, these samples could then be returned to Earth for analysis. With luck, these soil samples will reveal evidence of past life and prove that Mars was once a habitable planet!
Mars’ south polar ice cap. Credit: ESA / DLR / FU Berlin /
According to evidence gathered by multiple robotic orbiters, rovers, and landers over the course of several decades, scientists understand that Mars was once a warmer, watery place. But between 4.2 and 3.7 billion years ago, this began to change. As Mars magnetic field disappeared, the atmosphere slowly began to be stripped away by solar wind, leaving the surface the cold and dry and making it impossible for water to exist in liquid form.
While much of the planet’s water is now concentrated in the polar ice caps, scientists have speculated some of Mars’ past water could still be located underground. Thanks to a new study by a team of Italian scientists, it has now been confirmed that liquid water still exists beneath Mars’ southern polar region. This discovery has put an end to a fifteen-year mystery and bolstered the potential for future missions to Mars.
Radar detection of water under the south pole of Mars. Credit: ESA/NASA/JPL/ASI/Univ. Rome
So far, robotic missions have revealed considerable evidence of past water on Mars. These include dried-out river valleys and gigantic outflow channels discovered by orbiters, and evidence of mineral-rich soils that can only form in the presence of liquid water by rovers and landers. Early evidence from the ESA’s Mars Express probe has also showed that water-ice exists at the planet’s poles and is buried in the layers interspersed with dust.
However, scientists have long suspected that liquid water could exist beneath the polar ice caps, much in the same way that liquid water is believed to underlie glaciers here on Earth. In addition, the presence of salts on Mars could further reduce the melting point of subsurface water and keep it in a liquid state, despite the sub-zero temperatures present on both the surface and underground.
For many years, data from the Mars Express’Mars Advanced Radar for Subsurface and Ionosphere Sounding (MARSIS) instrument – which has been used to study the southern polar region – has remained inconclusive. Like all ground-penetrating radar, this instrument relies on radar pulses to map surface topography and determine the properties of the materials that lie beneath the surface.
Luckily, after considerable analysis, the study team was able to develop new techniques that allowed them to collect enough high-resolution data to confirm the presence of liquid water beneath the southern ice cap. As Andrea Cicchetti, the MARSIS operations manager and a co-author on the new paper, indicated:
“We’d seen hints of interesting subsurface features for years but we couldn’t reproduce the result from orbit to orbit, because the sampling rates and resolution of our data was previously too low. We had to come up with a new operating mode to bypass some onboard processing and trigger a higher sampling rate and thus improve the resolution of the footprint of our dataset: now we see things that simply were not possible before.”
Water detection under the south pole of Mars. Credit: Context map: NASA/Viking; THEMIS background: NASA/JPL-Caltech/Arizona State University; MARSIS data: ESA/NASA/JPL/ASI/Univ. Rome; R. Orosei et al 2018
What they found was that the southern polar region is made of many layers of ice and dust down to a depth of about 1.5 km over a 200 km-wide area, and featured an anomalous area measuring 20-km wide. As Roberto Orosei, the principal investigator of the MARSIS experiment and lead author of the paper, explained in a recent ESA press release:
“This subsurface anomaly on Mars has radar properties matching water or water-rich sediments. This is just one small study area; it is an exciting prospect to think there could be more of these underground pockets of water elsewhere, yet to be discovered.”
After analyzing the properties of the reflected radar signals and taking into account the composition of the layered deposits and expected temperature profiles below the surface, the scientists concluded that the 20-km wide feature is an interface between the ice and a stable body of liquid water. For MARSIS to be able to detect such a patch of water, it would need to be at least several tens of centimeters thick.
These findings also raise the possibility of there being life on Mars, both now and in the past. This is based on research that found microbial life in Lake Vostok, which is located some 4 km (2.5 mi) below the ice in Antarctica. If life can thrive in salty, subglacial environments on Earth, then it is possible that they could survive on Mars as well. Determining if this is the case will be the purpose of existing and future missions to Mars.
The MARSIS instrument on the Mars Express is a ground penetrating radar sounder used to look for subsurface water and ice. Credit: ESA
As Dmitri Titov, one of the Mars Express project scientist, explained:
“The long duration of Mars Express, and the exhausting effort made by the radar team to overcome many analytical challenges, enabled this much-awaited result, demonstrating that the mission and its payload still have a great science potential. This thrilling discovery is a highlight for planetary science and will contribute to our understanding of the evolution of Mars, the history of water on our neighbour planet and its habitability.”
The Mars Express launched on June 2nd, 2003, and will celebrate 15 years in orbit of Mars by December 25th this year. In the coming years, it will be joined by the ESA’s ExoMars 2020 mission, NASA’s Mars 2020 Rover, and a number of other scientific experiments. These missions will pave the way for a potential crewed mission, which NASA is planning to mount by the 2030s.
If there is indeed liquid water to be found on Mars, it will go a long way towards facilitating future research and even an ongoing human presence on the surface. And if there is still life on Mars, the careful research of its ecosystems will help address the all-important question of how and when life emerged in the Solar System.
A blood red moon captured during the total lunar eclipse of January 31st, 2018. Image credit and copyright: Eliot Herman
A blood red moon captured during the total lunar eclipse of January 31st, 2018. Image credit and copyright: Eliot Herman
The Blood Moon cometh.
One of the top astronomy events of 2018 occurs on the evening of Friday, July 27th, when the Moon enters the shadow of the Earth for a total lunar eclipse. In the vernacular that is the modern internet, this is what’s becoming popularly known as a “Blood Moon,” a time when the Moon reddens due to the refracted sunlight from a thousand sunsets falling upon it. Standing on the surface of the Moon during a total lunar eclipse (which no human has yet to do) you would see a red “ring of fire” ’round the limb of the eclipsed Earth.
This is the second total lunar eclipse for 2018, and the middle of a unique eclipse season bracketed by two partial solar eclipses, one on July 13th, and another crossing the Arctic and Scandinavia on August 11th.
The path of the Moon through the Earth’s shadow Friday, along with visibility prospects worldwide. Credit: NASA/GSFC
The July 27th total lunar eclipse technically begins around 17:15 Universal Time (UT), when the Moon enters the bright penumbral edge of the Earth’s shadow. Expect the see a slight shading on the southwest edge of the Moon’s limb about 30 minutes later. The real action begins around 18:24 UT, when the Moon starts to enter the dark inner umbra and the partial phases of the eclipse begin. Totality runs from 19:30 UT to 21:13 UT, and the cycle reverses through partial and penumbral phases, until the eclipse ends at 23:29 UT.
Centered over the Indian Ocean region, Africa, Europe and western Asia get a good front row seat to the entire total lunar eclipse. Australia and eastern Asia see the eclipse in progress at moonset, and South America sees the eclipse in progress at moonrise just after sunset. Only North America sits this one out.
Now, this total lunar eclipse is special for a few reasons.
First off, we’ll have the planet Mars at opposition less than 15 hours prior to the eclipse. This means the Red Planet will shine at a brilliant magnitude -2.8, just eight degrees from the crimson Moon during the eclipse, a true treat and an easy crop to get both in frame. We fully expect to see some great images of Mars at opposition along with the eclipsed Moon.
Mars versus the eclipsed Moon on Friday. Credit: Stellarium
How close can the two get? Well, stick around until April 27th, 2078 and you can see the Moon occult (pass in front of) Mars during a penumbral lunar eclipse as seen from South America.
And speaking of occultations, the Moon occults some interesting stars during totality Friday, the brightest of which is the +5.9 magnitude double star Omicron Capricorni (SAO 163626) as seen from Madagascar and the southern tip of Africa. Omicron Capricorni has a wide separation of 22″.
The occultation path of Omicron Capricorni during Friday’s eclipse. Credit: Occult 4.2.
The second unique fact surrounding this eclipse is one you’ve most likely already heard: it is indeed the longest one for this century… barely. This occurs because the Moon reaches its descending node along the ecliptic on July 27th at 22:40 UT, just 21 minutes after leaving the umbral shadow of the Earth. This makes for a very central eclipse, nearly piercing the umbral shadow of the Earth right through its center.
Totality on Friday lasts for 1 hour, 42 minutes and 57 seconds. This was last beat on July 16th, 2000 with a duration of 1 hour, 46 minutes and 24 seconds (2001 is technically the first year of the 21st century). The duration for Friday’s eclipse won’t be topped until June 9th 2123 (1 hour 46 minutes six seconds), making it the longest for a 123 year span.
The longest total lunar eclipse over the span of 5,000 years from 2000 BC to 3000 AD was on May 31st, 318 AD at 106.6 minutes in duration.
A Minimoon Eclipse
Finally, a third factor is assisting this eclipse in its longevity is the onset of the MiniMoon: The Moon reaches apogee at July 27th, 5:22 UT, 14 hours and 37 minutes prior to Full and the central time of the eclipse. This is the most distant Full Moon of the year for 2018 (406,222 km at apogee) the 2nd most distant apogee for 2018. Apogee on January 15th, beats it out by only 237 kilometers. This not only gives the Moon a slightly smaller size visually at 29.3′, versus 34.1′ near perigee, less than half of the 76′ arcminute diameter of the Earth’s shadow. This also means that the Moon is moving slightly slower in its orbit, making a more stately pass through the Earth’s shadow.
Going, going… the stages of a lunar eclipse. Credit: Dave Dickinson.
What will the Moon look like during the eclipse? Not all total lunar eclipses are the same, but I’d expect a dark, brick red hue from such a deep eclipse. The color of the Moon during a eclipse is described as its Danjon number, ranging from a bright (4) to dark murky copper color (0) during totality.
Tales of the Saros
This particular eclipse is member 38 of the 71 lunar eclipses in saros series 129, running from June 10th, 1351 all the way out to the final eclipse in the series on July 24th, 2613 AD. If you caught the super-long July 16th, 2000 eclipse (the longest for the 20th century) then you saw the last one in the series, and the next one for the series occurs on August 7th, 2036. Collect all three, and you’ve completed a triple exeligmos series, a fine word in Scrabble to land on a triple word score.
Photographing the Moon
If you can shoot the Moon, you can shoot a total lunar eclipse, though a minimum focal length lens of around 200mm is needed to produce a Moon much larger that a dot. The key moment is the onset of totality, when you need to be ready to rapidly dial the exposure settings down from the 1/100th of a second range down to 1 second or longer. Be careful not to lose sight of the Moon in the viewfinder all together!
Are you watching the eclipse during moonrise or moonset? This is a great time to shoot the eclipsed Moon along with foreground objects… you can also make an interesting observation around this time, and nab the eclipsed Moon and the Sun above the local horizon at the same time in what’s termed a selenelion. This works mainly because the Earth’s shadow is larger than the apparent diameter of the Moon, allowing it to be cast slightly off to true center after sunrise or just before sunset. Gaining a bit of altitude and having a low, flat horizon helps, as the slight curve of the Earth also gives the Sun and Moon a tiny boost. For this eclipse, the U2-U3 umbral contact zone for a selenelion favors eastern Brazil, the UK and Scandinavia at moonrise, and eastern Australia, Japan and northeastern China at moonset.
Incidentally, a selenelion is the second visual proof you see during a lunar eclipse that the Earth is indeed round, the first being the curve of the planet’s shadow seen at all angles as it falls across the Moon.
Another interesting challenge would be to capture a transit of the International Space Station during the eclipse, either during the partial or total phases… to our knowledge, this has never been done during a lunar eclipse. This Friday, South America gets the best shots at a lunar eclipse transit of the ISS:
ISS transit paths (revised) during Friday’s eclipse, including times in UT and Moon phases. The northern and southern limits of the paths mark the point where the Moon is no longer visible. Created by the author using CalSky. (Thanks to PAHLES in comments below for pointing out the errors in the first map!)
Watch Friday’s eclipse live online. Credit: Gianluca Masi/Virtual Telescope Project.
Live on the wrong continent, or simply have cloudy skies? Gianluca Masi and the Virtual Telescope Project 2.0 have you covered, with a live webcast of the eclipse from the heart of Rome, Italy on July 27th starting at 18:30 UT.
Be sure to catch Friday’s total lunar eclipse, either in person or online… we won’t have another one until January 21st, 2019.
Learn about eclipses, occultations, the motion of the Moon and more in our new book: Universe Today’s Guide to the Cosmos: Everything You Need to Know to Become an Amateur Astronomer now available for pre-order.
This low-angle self-portrait of NASA's Curiosity Mars rover shows the vehicle at the site from which it reached down to drill into a rock target called "Buckskin" on lower Mount Sharp. Credits: NASA/JPL-Caltech/MSSS
Martian dust storms, which occur during the summer season in the planet’s southern hemisphere, can get pretty intense. Over the course of the past few weeks, a global dust storm has engulfed Mars and forced the Opportunity rover to suspend operations. Given that this storm is much like the one that took place back in 2007, which also raged for weeks, there have been concerns over how this development could affect rover operations.
Meanwhile the Curiosity rover managed to snap pictures of the thickening haze caused by the storm. Though Curiosity is on the other side of the planet from where Opportunity is currently located, atmospheric dust has been gradually increasing over it. But unlike Opportunity, which runs on solar power, Curiosity will remain unaffected by the global storm thanks to its nuclear-powered battery, and is therefore in a good position to study it.
As already noted, Martian storms occur during summer in the southern hemisphere, when sunlight warms dust particles and lifts them higher into the atmosphere, creating more wind. The resulting wind kicks up yet more dust, creating a feedback loop that NASA scientists are still trying to understand. Since the southern polar region is pointed towards the Sun in the summer, carbon dioxide frozen in the polar cap evaporates.
Global map of Mars produced by the Mars Color Imager (MARCI) camera on NASA’s Mars Reconnaissance Orbiter (MRO), which shows a growing dust storm as of June 6th, 2018. The blue dot indicates the approximate location of Opportunity. Credit: NASA/JPL-Caltech/MSSS
This has the effect of thickening the atmosphere and increasing the surface pressure, which enhances the process by helping suspend dust particles in the air. In some cases, the dust clouds can reach up to 60 km (40 mi) or more in elevation. Though they are common and can begin suddenly, Martian dust storms typically stay contained to a local area and last only about a weeks.
By contrast, the current storm has lasted for several weeks and is currently covering an area that would span North America and Russia combined. While smaller than the storm that took place back in 2007, this storm has intensified to the point where it created a perpetual state of night over the rover’s location in Perseverance Valley and led to a level of atmospheric opacity that is much worse than the 2007 storm.
When dust storms occur, scientists measure them based on their opacity level (tau) to determine how much sunlight they will prevent from reaching the surface. Whereas the 2007 storm had a tau level of about 5.5, this most recent storm reached an estimated tau of 10.8 earlier this month over the Perseverance Valley – where Opportunity is located.
The intensity of the storm also led Bruce Canton, deputy principal investigator of the Mars Color Imager (MARCI) camera onboard NASA’s Mars Reconnaissance Orbiter (MRO), to declare that the storm has officially become a “planet-encircling” (or “global”) dust event. Above the Gale Crater, where Curiosity is located, the tau reading is now above 8.0 – the highest ever recorded by the mission.
In June 2018 NASA’s Curiosity Rover used its Mast Camera, or Mastcam, to snap photos of the intensifying haziness the surface of Mars, caused by a massive dust storm. The photos span about a couple of weeks, starting with a shot of the area before the storm appeared. Credits: NASA
While the storm has some worried about the fate of Opportunity, which is Mars’ oldest active rover (having remained in operation for over 14 years), it is also an chance to address one of the greatest questions scientists have about Mars. For example, why do some storms span the entire planet and last for months while others are confined to small areas and and last only a week?
The animation (shown above) consists of a series of daily photos captures by Curiosity’s Mast Camera (Mastcam), which show the sky getting hazier over time. While taking these pictures, Curiosity was facing the crater rim, about 30 km (18.6) away from where it stands inside the crater. This sun-obstructing wall of haze is about six to eight times thicker than normal for this time of season.
Nevertheless, Curiosity’s engineers – which are based at NASA’s Jet Propulsion Laboratory in Pasadena, California – have studied how the growing dust storm could affect the rover’s instruments and concluded that it poses little risk. Ironically enough, the largest impact will be on the rover’s cameras, which require extra exposure time due to the low lighting conditions.
Two images from the Mast Camera (Mastcam) on NASA’s Curiosity rover depicting the change in the color of light illuminating the Martian surface since a dust storm engulfed Gale Crater. Credits: NASA/JPL-Caltech/MSSS
As Jim Watzin, the director of NASA’s Mars Exploration Program at the agency’s headquarters in Washington, explained in a NASA press release earlier this month:
“This is the ideal storm for Mars science. We have a historic number of spacecraft operating at the Red Planet. Each offers a unique look at how dust storms form and behave – knowledge that will be essential for future robotic and human missions.”
However, all dust events, regardless of size, help to shape the Martian surface. As such, studying their physics is critical to understanding the Martian climate, both past and present. As Rich Zurek, the chief scientist for the Mars Program Office at NASA’s Jet Propulsion Laboratory, indicated:
“Each observation of these large storms brings us closer to being able to model these events – and maybe, someday, being able to forecast them. That would be like forecasting El Niño events on Earth, or the severity of upcoming hurricane seasons.”
The ability to understand the causes and dynamics of Martian dust storms would not only lead to a better understand of how weather works on other planets, it would also be of immense importance if and and when humans begin traveling to the Red Planet on a regular basis. For instance, if SpaceX really does intend to bring tourists to Mars in the future, said tourists will want to avoid booking during “storm season”.
And if humans should choose to someday make Mars their home, they will need to know when planet-spanning dust storms are coming, especially since their habitats will likely be relying on wind and solar power. In the meantime, NASA and other space agencies will continue to monitor this storm and the Opportunity rover is expected to come through (fingers crossed!) unscathed!
A 13-kilometer (8-mile) diameter crater being infilled by the Medusae Fossae Formation. Credit: High Resolution Stereo Camera/European Space Agency.
Scientists first observed the Medusae Fossae Formation (MFF) in the 1960s, thanks to the efforts of the Mariner spacecraft. This massive deposit of soft, sedimentary rock extends for roughly 1,000 km (621 mi) along the equator and consists of undulating hills, abrupt mesas, and curious ridges (aka. yardangs) that appear to be the result of wind erosion. What’s more, an unusual bump on top of this formation also gave rise to a UFO conspiracy theory.
Needless to say, the formation has been a source of scientific curiosity, with many geologists attempting to explain how it could have formed. According to a new study from Johns Hopkins University, the region was the result of volcanic activity that took place on the Red Planet more than 3 billion years ago. These findings could have drastic implications for scientists’ understanding of Mars’ interior and even its past potential for habitability.
Perspective view of Medusa Fossae looking south-east. Copyright: ESA/DLR/FU Berlin (G. Neukum)
Ojha’s past work includes finding evidence that water on Mars occurs in seasonal brine flows on the surface, which he discovered in 2010 as an undergraduate student. Lewis, meanwhile, has dedicated much of his academic carreer to the in-depth study of the nature of sedimentary rock on Mars for the sake of determining what this geological record can tell us about that planet’s past climate and habitability.
As Ojha explained, the study of the Medusa Fossae Formation is central to understanding Mars geological history. Much like the Tharsus Montes region, this formation was formed at a time when the planet was still geologically active. “This is a massive deposit, not only on a Martian scale, but also in terms of the solar system, because we do not know of any other deposit that is like this,” he said.
Basically, sedimentary rock is the result of rock dust and debris accumulating on a planet’s surface and becoming hardened and layered over time. These layers serve as a geological record, indicating what types of processes where taking place on the surface at the time that the layers were deposited. When it comes to the Medusae Fossae Formation, scientists were unsure whether wind, water, ice or volcanic eruptions were responsible for the deposits.
In the past, radar measurements were made of the formation that suggested that Medusae Fosssae had an unusual composition. However, scientists were unsure whether the formation was made of highly porous rock or a mixture of rock and ice. For the sake of their study, Ojha and Lewis used gravity data from various Mars orbiters to measure the formation’s density for the first time.
An isolated hill in the Medusae Fossae Formation. The effect of wind erosion on this hill is evident by its streamlined shape. Credit: High Resolution Stereo Camera/European Space Agency
What they found was that the rock is unusually porous and about two-thirds as dense as the rest of the Martian crust. They also used radar and gravity data to show that the Formation’s density was too great to be explained by the presence of ice. From this, they concluded that the heavily-porous rock had to have been deposited by volcanic eruptions when Mars was still geologically active – ca. 3 billion years ago.
As these volcanoes exploded, casting ash and rock into the atmosphere, the material would have then fallen back to the surface, building up layers and streaming down hills. After enough time, the ash would have cemented into rock, which was slowly eroded over time by Martian winds and dust storms, leaving the Formation scientists see there today. According to Ojha, these new findings suggest that Mars’ interior is more complex than previously thought.
While scientists have known for some time that Mars has some volatiles – i.e. water, carbon dioxide and other elements that become gas with slight increases in temperature – in its crust that allow for periodic explosive eruptions to occur on the surface, the kind of eruption needed to create the Medusa Fossae region would have been immense. This indicates that the planet may have massive amounts of volatiles in its interior. As Ojha explained:
“If you were to distribute the Medusae Fossae globally, it would make a 9.7-meter (32-foot) thick layer. Given the sheer magnitude of this deposit, it really is incredible because it implies that the magma was not only rich in volatiles and also that it had to be volatile-rich for long periods of time.”
According to Ojha and Lewis’ study, the eruption that created the Medusa Fossae Formation would have covered Mars in a global ocean. Image: ESO/M. Kornmesser, via N. Risinger
In addition, this activity would have had a drastic impact on Mars’ past habitability. Basically, the formation of the Medusae Fossae Formation would have occurred during a pivotal point in Mars’ history. After the eruption occurred, massive amounts of carbon dioxide and (most likely) methane would have been ejected into the atmosphere, causing a significant greenhouse effect.
In addition, the authors indicated that the eruption would have ejected enough water to cover Mars in a global ocean more than 9 cm (4 inches) in thickness. This resulting greenhouse effect would have been enough to keep Mars’ surface warm to the point that the water would remain in a liquid state. At the same time, the expulsion of volcanic gases like hydrogen sulfide and sulfur dioxide would have altered the chemistry of Mars’ surface and atmosphere.
All of this would have had a drastic impact on the planet’s potential habitability. What’s more, as Kevin Lewis indicated, the new study shows that gravity surveys have the potential to interpret Mars’ geological record. “Future gravity surveys could help distinguish between ice, sediments and igneous rocks in the upper crust of the planet,” he said.
Studying Mars surface features and geological history is a lot like peeling an onion. With every layer we peel back, we get another piece of the puzzle, which together adds up to a rich and varied history. In the coming years and decades, more robotic missions will be studying the Red Planet’s surface and atmosphere in preparation for an eventual crewed mission by the 2030s.
All of these missions will allow us to learn more about Mars warmer, wetter past and whether or not may have existed there at some time (or perhaps, still does!)
Artist's conception of a terraformed Mars. Credit: Ittiz/Wikimedia Commons
Billions of years ago, Earth’s atmosphere was much different than it is today. Whereas our current atmosphere is a delicate balance of nitrogen gas, oxygen and trace gases, the primordial atmosphere was the result of volcanic outgassing – composed primarily of carbon dioxide, methane, ammonia, and other harsh chemicals. In this respect, our planet’s ancient atmosphere has something in common with Mars’ current atmosphere.
For this reason, some researchers think that introducing photosynthetic bacteria, which helped covert Earth’s atmosphere to what it is today, could be used to terraform Mars someday. According to a new study by an international team of scientists, it appears that cyanobacteria can conduct photosynthesis in low-light conditions. The results of this study could have drastic implications for Mars, where low-light conditions are common.
Cyanobacteria are some of the most ancient organisms on Earth, with fossil evidence indicating that they existed as early as the Archean Era (c.a 3.5 billion years ago). During this time, they played a vital role in converting the abundant CO² in the atmosphere into oxygen gas, which eventually gave rise to ozone (O³) that helped protect the planet from harmful solar radiation.
The photochemistry used by these microbes is similar to what plants and trees – which subsequently evolved – rely on today. The process comes down to red light, which plants absorb, while reflecting green lights thanks to their chlorophyll content. The darker the environment, the less energy plants are able to adsorb, and thus convert into chemical energy.
For the sake of their study, the team led by Nürnberg sought to investigate just how dark an environment can become before photosynthesis becomes impossible. Using a species of bacteria known as Chroococcidiopsis thermalis (C. thermalis), they exposed samples of cyanobacteria to low light to find out what the lowest wavelengths that they could absorb were.
Previous research has suggested that the lower limit for photochemistry to occur was a light wavelength of 700 nanometers – known as the “red limit”. However, the team found that C. thermalis continued to conduct photosynthesis at wavelengths of up to 750 nanometers. The key, according to the team, lies in the presence of previously undetected long-wavelength chlorophylls, which the researchers traced back to the C. thermalis genome.
The researchers traced the origin of these chlorophylls to the C. thermalis genome, which they located in a specific gene cluster that is common in many species of cyanobacteria. This suggests that the ability to surpass the red limit is actually quite common, which has numerous implications. For one, the findings indicate that the limits of photosynthesis are greater than previously thought.
On the other hand, these findings indicate that certain organisms can function using less fuel, which the researchers refer to as an “unprecedented low-energy photosystem”. To Krausz and his colleagues, this photosystem could be the first wave in an effort to terraform Mars. Along with efforts to thicken the atmosphere and warm the environment, the introduction of C. thermalis and terrestrial plants could slowly make Mars suitable for human habitation.
“This might sound like science fiction, but space agencies and private companies around the world are actively trying to turn this aspiration into reality in the not-too-distant future. Photosynthesis could theoretically be harnessed with these types of organisms to create air for humans to breathe on Mars. Low-light adapted organisms, such as the cyanobacteria we’ve been studying, can grow under rocks and potentially survive the harsh conditions on the red planet.”
Artist’s concept of a Martian astronaut standing outside the Mars One habitat. Credit: Bryan Versteeg/Mars One
In this respect, Krausz and his colleagues are joined by groups like the CyanoKnights – a team of students and volunteer scientists from the University of Applied Science and the Technical University in Darmstadt, Germany. Much like Krausz’s team, the CyanoKnights that want to seed Mars with cyanobacteria in order to trigger an ecological transformation, thus paving the way for colonization.
This idea was submitted as part of the Mars One University Competition, which took place in the summer of 2014. What’s more, there have been recent research findings that indicate that organisms similar to cyanobacteria may already exist on other planets. If this most recent study is correct, it means that such organisms could survive in low-light conditions, which means astronomers could expand their search for potential life to other locations in the Universe.
From offering humans the means to conduct terraforming under more restrictive conditions to assisting in the search for extra-terrestrial life, this research could have some drastic implications for our understanding of life in the Universe, and how to expand our place in it.
