Artist’s impression depicting the separation of the ExoMars 2016 entry, descent and landing demonstrator module, named Schiaparelli, from the Trace Gas Orbiter, and heading for Mars. Credit: ESA/D. Ducros
In March of 2016, the European Space Agency (ESA) launched the ExoMars (Exobiology on Mars) mission into space. A joint project between the ESA and Roscosmos, this two-part mission consisted of the Trace Gas Orbiter (TGO) and the Schiaparelli lander, both of which arrived in orbit around Mars in October of 2016. While Schiaparelli crashed while attempting to land, the TGO has gone on to accomplish some impressive feats.
For example, in March of 2017, the orbiter commenced a series of aerobraking maneuvers, where it started to lower its orbit to enter Mars’ thin atmosphere and slow itself down. According to Armelle Hubault, the Spacecraft Operations Engineer on the TGO flight control team, the ExoMars mission has made tremendous progress and is well on its way to establishing its final orbit around the Red Planet.
TGO’s mission has been to study the surface of Mars, characterize the distribution of water and chemicals beneath the surface, study the planet’s geological evolution, identify future landing sites, and to search for possible biosignatures of past Martian life. Once it has established its final orbit around Mars – 400 km (248.5 mi) from the surface – the TGO will be ideally positioned to conduct these studies.
Visualization of the ExoMars mission’s Trace Gas Orbiter conducting aerobraking maneuvers to March of 2018. Credit: ESA
The ESA also released a graphic (shown above) demonstrating the successive orbits the TGO has made since it began aerobraking – and will continue to make until March of 2018. Whereas the red dot indicates the orbiter (and the blue line its current orbit), the grey lines show successive reductions in the TGO’s orbital period. The bold lines denote a reduction of 1 hour while the thin lines denote a reduction of 30 minutes.
Essentially, a single aerobraking maneuver consist of the orbiter passing into Mars’ upper atmosphere and relying on its solar arrays to generate tiny amounts of drag. Over time, this process slows the craft down and gradually lowers its orbit around Mars. As Armelle Hubault recently posted on the ESA’s rocket science blog:
“We started on the biggest orbit with an apocentre (the furthest distance from Mars during each orbit) of 33 200 km and an orbit of 24 hr in March 2017, but had to pause last summer due to Mars being in conjunction. We recommenced aerobraking in August 2017, and are on track to finish up in the final science orbit in mid-March 2018. As of today, 30 Jan 2018, we have slowed ExoMars TGO by 781.5 m/s. For comparison, this speed is more than twice as fast as the speed of a typical long-haul jet aircraft.”
Earlier this week, the orbiter passed through the point where it made its closest approach to the surface in its orbit (the pericenter passage, represented by the red line). During this approach, the craft dipped well into Mars’ uppermost atmosphere, which dragged the aircraft and slowed it down further. In its current elliptical orbit, it reaches a maximum distance of 2700 km (1677 mi) from Mars (it’s apocenter).
Visualization of the ExoMars Trace Gas Orbiter aerobraking at Mars. Credit: ESA/ATG medialab
Despite being a decades-old practice, aerobraking remains a significant technical challenge for mission teams. Every time a spacecraft passes through a planet’s atmosphere, its flight controllers need to make sure that its orientation is just right in order to slow down and ensure that the craft remains stable. If their calculations are off by even a little, the spacecraft could begin to spin out of control and veer off course. As Hubault explained:
“We have to adjust our pericentre height regularly, because on the one hand, the martian atmosphere varies in density (so sometimes we brake more and sometimes we brake less) and on the other hand, martian gravity is not the same everywhere (so sometimes the planet pulls us down and sometimes we drift out a bit). We try to stay at about 110 km altitude for optimum braking effect. To keep the spacecraft on track, we upload a new set of commands every day – so for us, for flight dynamics and for the ground station teams, it’s a very demanding time!”
The next step for the flight control team is to use the spacecraft’s thrusters to maneuver the spacecraft into its final orbit (represented by the green line on the diagram). At this point, the spacecraft will be in its final science and operation data relay orbit, where it will be in a roughly circular orbit about 400 km (248.5 mi) from the surface of Mars. As Hubault wrote, the process of bringing the TGO into its final orbit remains a challenging one.
“The main challenge at the moment is that, since we never know in advance how much the spacecraft is going to be slowed during each pericentre passage, we also never know exactly when it is going to reestablish contact with our ground stations after pointing back to Earth,” she said. “We are working with a 20-min ‘window’ for acquisition of signal (AOS), when the ground station first catches TGO’s signal during any given station visibility, whereas normally for interplanetary missions we have a firm AOS time programmed in advance.”
Artist’s impression of the ESA’s Exomars 2020 rover, which is expected to land on the surface of Mars by the Spring of 2o21. Credit:ESA
With the spacecraft’s orbital period now shortened to less than 3 hours, the flight control team has to go through this exercise 8 times a day now. Once the TGO has reached its final orbit (by March of 2018), the orbiter will remain there until 2022, serving as a telecommunications relay satellite for future missions. One of its tasks will be to relay data from the ESA’s ExoMars 2020 mission, which will consist of a European rover and a Russian surface platform being deployed the surface of Mars in the Spring of 2021.
Along with NASA’s Mars 2020 rover, this rover/lander pair will be the latest in a long line of robotic missions looking to unlock the secrets of Mars past. In addition, these missions will conduct crucial investigations that will pave the way for eventual sample return missions to Earth, not to mention crewed to the surface!
Mosaic image of the Curiosity rover on Mars, which recently turned up more evidence that supports the idea that the planet was once habitability. Credit: NASA/JPL-Caltech/MSSS.
On August 5th, 2012, after spending over 8 months in space, NASA’s Curiosity rover landed on Mars. As part of the NASA Mars Science Laboratory (MSL) mission, and the latest in a series of rovers deployed to the Martian surface, Curiosity had some rather ambitious research goals. In addition to investigating Mars’ climate and geology, the rover was also tasked with revealing more about Mars’ past and determining if it ever supported microbial life.
And recently, the Curiosity rover hit another major milestone in its exploration of the Red Planet. As of January 26th, 2018 the rover has spent a total of 2,000 days on Mars, which works out to 5 years, 5 months and 21 days – or 1947 Martian days (sols). That’s especially impressive when you consider that the mission was only meant to last 687 days (668 sols), or just little under 2 years.
In all that time, the Curiosity rover has accomplished some major feats and has the scars to prove it! Some of it’s wheels have become teared, holed and cracked and its drill has been pushed almost to the point of breaking. And yet, Curiosity is still hard at work pushing itself up a mountain – both literally and figuratively! The rover has also managed to exceed everyone’s expectations.
MRO image of Gale Crater illustrating the landing location and trek of the Rover Curiosity. Credits: NASA/JPL, illustration, T.Reyes
As Ashwin Vasavada, the MSL Project Scientist, told Universe Today via email:
“In terms of challenges, the first 2000 days of Curiosity’s mission went better than I could have hoped. For much of the time, the rover remained as capable as the day it landed. We had a scare in the first year when a memory fault triggered additional problems and nearly resulted in the loss of the mission. We famously wore down our wheels pretty early, as well, but since then we’ve kept that under control. In the last year, we’ve had a major problem with our drill. That’s the only major issue currently, but we believe we’ll be back to drilling in a month or so. If that works out, we’ll amazingly be back to having all systems ready for science!”
As of the penning of this article, the rover is climbing Mount Sharp in order to collect further samples from Mars’ past. Also known as Aeolis Mons, this mountain resides in the center of the Gale Crater where Curiosity landed in 2012 and has been central to Curiosity’s mission. Standing 5,500 meters (18,000 ft) above the valley floor, Mount Sharp is believed to have formed from sediment that was slowly deposited by flowing water over billions of years.
This is all in keeping with current theories about how Mars once had a denser atmosphere and was able to sustain liquid water on its surface. But between 4.2 and 3.7 billion years ago, this atmosphere was slowly stripped away by solar wind, thus turning Mars into the cold and desiccated place that we know today. As a result, the study of Mount Sharp was always expected to reveal a great deal about Mars’ geological evolution.
Image of Mount Sharp taken by the Curiosity rover on Aug. 23rd, 2012. The layers at the base of Mt. Sharp show the geological history of Mars. Credit: NASA/JPL-Caltech/MSSS.
In it’s first year, Curiosity achieved a major milestone when the rover obtained drill samples from low-lying areas that indicated that lakes and streams existed in the Gale Crater between 3.3 to 3.8 billion years ago. In addition, the rover has also obtained ample evidence that the crater once had all the chemical elements and even a chemical source of energy needed for microbial life to exist.
“NASA’s charge to our mission was to determine whether Mars ever had conditions suitable for life,” said Vasavada. “Success was not a foregone conclusion. Would we arrive safely? Would the scientific instruments work? Would the area we chose for the landing site hold the clues we were looking for? For me, meeting each of these objectives are the highlights of the mission. I’ll never forget witnessing the launch, or nervously waiting for a safe touchdown. Discovering an ancient, freshwater lake environment at Gale crater was profound scientifically, but also was the moment that I knew that our team had delivered what we promised to NASA.”
Basically, by scaling Mount Sharp and examining the layers that were deposited over the course of billions of years, Curiosity is able to examine a living geological record of how the planet has evolved since then. Essentially, the lower layers of the mountain are believed to have been deposited 3.5 billion years ago when the Gale Crater was still a lakebed, as evidenced by the fact that they are rich in clay minerals.
The upper layers, meanwhile, are believed to have been deposited over the ensuing millions of years, during which time the lake in the Gale Crater appears to have grown, shrunk, disappeared and then reappeared. Basically, by scaling the mountain and obtaining samples, Curiosity will be able to illustrate how Mars underwent the transition from being a warmer, wetter place to a frozen and dry one.
Image taken of drill sample obtained at the ‘Lubango’ outcrop target on Sol 1320, Apr. 23, 2016. Lubango is located in the Stimson unit on the lower slopes of Mount Sharp inside Gale Crater. Credit: NASA/JPL/MSSS/Ken Kremer/kenkremer.com/Marco Di Lorenzo
As Vasavada explained, this exploration is also key to answering a number of foundational questions about the search for life beyond Earth:
“Curiosity established that Mars was once a suitable home for life; it had liquid water, key chemical building blocks, and energy sources required by life in the lake and groundwater environment within Gale crater. Curiosity also has detected organic molecules in ancient rocks, in spite of all the degradation that could have occurred in three billion years. While Curiosity cannot detect life itself, knowing that Mars can preserve organic molecules bodes well for missions that will explore ancient rocks, looking for signs of past life.”
At this juncture, its not clear how much longer Curiosity will last. Considering that it has already lasted over twice as long as originally intended, it is possible the rover will remain in operation for years to come. However, unlike the Opportunity rover – who’s mission was intended to last for 90 days, but has remained in operation for 5121 days (4984 sols) – Curiosity has a shelf life.
Whereas Opportunity is powered by solar cells, Curiosity is dependent on its Multi-Mission Radioisotope Thermoelectric Generator (MMRTG). Eventually, this slow-fission reactor will exhaust its supply of nuclear fuel and the rover will be forced to come to a halt. And considering how the rover has been put through its paces in the past 5 years, there’s also the chance that it will suffer a mechanical failure.
But in the meantime, there’s plenty of work to be done and lots of opportunities for vital research. As Vasavada put it:
“Curiosity won’t last forever, but in the years we have left, I hope we can complete our traverse through the lowermost strata on Mount Sharp. We’re well over halfway through. There are changes in the composition of the rocks ahead that might tell us how the climate of Mars changed over time, perhaps ending the era of habitability. Every day on Mars still counts, perhaps even more than before. Now every new discovery adds a piece to a puzzle that’s more than halfway done; it reveals more given all the other pieces already around it.”
And be sure to check out this retrospective of the Curiosity rover’s mission, courtesy of NASA:
The Insight lander responds to commands to spread its solar arrays during a January 23, 2018 test at the Lockheed Martin clean room in Littleton, Colorado. Image: Lockheed Martin Space
May 2018 is the launch window for NASA’s next mission to Mars, the InSight Lander. InSight is the next member of what could be called a fleet of human vehicles destined for Mars. But rather than working on the question of Martian habitability or suitability for life, InSight will try to understand the deeper structure of Mars.
InSight stands for Interior Exploration using Seismic Investigations, Geodesy and Heat Transport. InSight will be the first robotic explorer to visit Mars and study the red planet’s deep interior. The work InSight does should answer questions about the formation of Mars, and those answers may apply to the history of the other rocky planets in the Solar System. The lander, (InSight is not a rover) will also measure meteorite impacts and tectonic activity happening on Mars currently.
This video helps explain why Mars is a good candidate to answer questions about how all our rocky planets formed, not just Mars itself.
InSight was conceived as part of NASA’s Discovery Program, which are missions focused on important questions all related to the “content, origin, and evolution of the solar system and the potential for life elsewhere”, according to NASA. Understanding how our Solar System and its planets formed is a key part of the Discovery Program, and is the question InSight was built to answer.
This artist’s illustration of InSight on a photo background of Mars shows the lander fully deployed. The solar arrays are open, and in the foreground two of its instruments are shown. On the left is the SEIS instrument, and on the right is the HP3 probe. Image: NASA/Lockheed Martin
To do its work, InSight will deploy three instruments: SEIS, HP³, and RISE.
SEIS
This is InSight’s seismic instrument, designed to take the Martian pulse. It stands for Seismic Experiment for Internal Structure.
In this image, InSight’s Instrument Deployment Arm is practicing placing SEIS on the surface. Image: NASA/Lockheed Martin
SEIS sits patiently under its dome, which protects it from Martian wind and thermal effects, and waits for something to happen. What’s it waiting for? For seismic waves caused by Marsquakes, meteorite impacts, or by the churning of magma deep in the Martian interior. These waves will help scientists understand the nature of the material that first formed Mars and the other rocky planets.
HP³
HP³ is InSight’s heat probe. It stands for Heat Flow and Physical Properties Probe. Upon deployment on the Martian surface, HP³ will burrow 5 meters (16 ft.) into Mars. No other instrument has ever pierced Mars this deeply. Once there, it will measure the heat flowing deeply within Mars.
In this image, the Heat Flow and Physical Properties Probe is shown inserted into Mars. Image: NASA
Scientists hope that the heat measured by HP³ will help them understand whether or not Mars formed from the same material that Earth and the Moon formed from. It should also help them understand how Mars evolved after it was formed.
RISE
RISE stands for Rotation and Interior Structure Experiment. RISE will measure the Martian wobble as it orbits the Sun, by precisely tracking InSight’s position on the surface. This will tell scientists a lot about the deep inner core of Mars. The idea is to determine the depth at which the Martian core is solid. It will also tell us which elements are present in the core. Basically, RISE will tell us how Mars responds to the Sun’s gravity as it orbits the Sun. RISE consists of two antennae on top of InSight.
The two RISE antennae are shown in this image. RISE will reveal information about the Martian core by tracking InSight’s position while Mars orbits the Sun. Image: NASA/Lockheed Martin
InSight will land at Elysium Planitia which is a flat and smooth plain just north of the Martian equator. This is considered a perfect location or InSight to study the Martian interior. The landing sight is not far from where Curiosity landed at Gale Crater in 2012.
InSight will land at Elysium Planitia, just north of the Martian equator. Image: NASA/JPL-CalTech
InSight will be launched to Mars from Vandenberg Air Force Base in California by an Atlas V-401 rocket. The trip to Mars will take about 6 months. Once on the Martian surface, InSight’s mission will have a duration of about 728 Earth days, or just over 1 Martian year.
InSight won’t be launching alone. The Atlas that launches the lander will also launch another NASA technology experiment. MarCO, or Mars Cube One, is two suitcase-size CubeSats that will travel to Mars behind InSight. Once in orbit around Mars, their job is to relay InSight data as the lander enters the Martian atmosphere and lands. This will be the first time that miniaturized CubeSat technology will be tested at another planet.
One of the MarCO Cubesats that will be launched with InSight. This will be the first time that CubeSat technology will be tested at another planet. Image: NASA/JPL-CalTech
If the MarCO experiment is successful, it could be a new way of relaying mission data to Earth. MarCO will relay news of a successful landing, or of any problems, much sooner. However, the success of the InSight lander is not dependent on a successful MarCO experiment.
Using the microlensing metthod, a team of astrophysicists have found the first extra-galactic planets! Credit: NASA/Tim Pyle
The study of exoplanets has advanced by leaps and bounds in the past few decades. Between ground-based observatories and spacecraft like the Kepler mission, a total of 3,726 exoplanets have been confirmed in 2,792 systems, with 622 systems having more than one planet (as of Jan. 1st, 2018). And in the coming years, scientists expect that many more discoveries will be possible thanks to the deployment of next-generation missions.
These include NASA’sJames Webb Space Telescope (JWST) and several next-generation ground based observatories. With their advanced instruments, these and other observatories are not only expected to find many more exoplanets, but to reveal new and fascinating things about them. For instance, a recent study from Columbia University indicated that it will be possible, using the Transit Method, to study surface elevations on exoplanets.
The study, which recently appeared online under the title “Finding Mountains with Molehills: The Detectability of Exotopography“, was conducted by Moiya McTier and David Kipping – and graduate student and an Assistant Professor of Astronomy at Columbia University, respectively. Based on models they created using bodies in our Solar System, the team considered whether transit surveys might be able to reveal topographical data on exoplanets.
Artist’s impression of an extra-solar planet transiting its star. Credit: QUB Astrophysics Research Center
To recap, the Transit Method (aka. Transit Photometry) is currently the most popular and reliable means for detecting exoplanets. It consists of astronomers measuring the light curve of distant stars over time and looking for periodic dips in brightness. These dips are the result of exoplanets passing in front of the star (i.e. transiting) relative to the observer.
By measuring the rate at which the star’s light dips, and the period with which the dimming occurs, astronomer are not only able to determine the presence of exoplanets, but also place accurate constraints on their size and orbital periods. According to McTier and Kipping, this same method could also reveal the presence of geographical features – for instance, mountain ranges, volcanoes, trenches, and craters.
As they indicate in their study, in lieu of direct imaging, indirect methods are the only means astronomers have for revealing data on an exoplanet’s surface. Unfortunately, there is no conceivable way that the radial velocity, microlensing, astrometry, and timing methods could reveal exotopography. This leaves the transit method, which has some potential in this respect. As they state:
“The transit method directly measures the sky-projected area of a planet’s silhouette relative to that of a star, under the assumption that the planet is not luminous itself… This fact implies that there is indeed some potential for transits to reveal surface features, since the planet’s silhouette is certainly distorted from a circular profile due to the presence of topography.”
Satellite image of the Himalayan mountain chain, as imaged by NASA’sLandsat-7 imagery of Himalayas. Credit: NASA
In other words, as a planet transits in front of its host star, the light passing around the planet itself could be measured for small variations. These could indicate the presence of mountain ranges and other large-scale features like massive chasms. To test this theory, they considered planets in the Solar System as templates for how the scattering of light during a transit could reveal large-scale features.
As an example, they consider what an Earth analog planet would reveal if the Himalayan mountain range ran from north to south and was wide enough to span 1° in longitude:
“Now assume that the planet completes half of one rotation as it transits its parent star from our point of view, which is all that is necessary to see all of the planet’s features appear on its silhouette without repeating. As our hypothetical planet rotates and the Himalayan block moves into and out of view, the change in silhouette will result in different transit depths…”
Ultimately, they consider that Mars would be the ideal test case due to its combination of small size, low surface gravity, and active internal volcanism, which has caused it become what they describe as the “bumpiest body in the Solar System”. When paired with a white dwarf star, this presents the optimal case for using light curves to determine exotopography.
Color mosaic of Mars’ greatest mountain, Olympus Mons, viewed from orbit. Credit NASA/JPL
At a distance of about 0.01 AU (which would be within a white dwarf’s habitable zone), they calculate that a Mars-sized planet would have an orbital period of 11.3 hours. This would allow for many transits to be observed in a relatively short viewing period, thus ensuring a greater degree of accuracy. At the same time, the team admits that their proposed methods suffers from drawbacks.
For instance, due to the presence of astrophysical and instrumental noise, they determined that their method would be unproductive when it comes to studying exoplanets around Sun-like stars and M-type (red dwarf) stars. But for Mars-like planets orbiting low mass, white dwarf stars, the method could produce some highly valuable scientific returns.
While this might sound rather limited, it would present some rather fascinating opportunities to learn more about planets beyond our Solar System. As they explain:
“Finding the first evidence of mountains on planets outside our solar system would be exciting in its own right, but we can also infer planet characteristics from the presence and distribution of surface features. For example, a detection of bumpiness could lead to constraints on a planet’s internal processes.”
In short, planets with a high degree of bumpiness would indicate tectonic activity or the buildup of lava caused by internal heating sources. Those with the highest bumpiness (i.e. like Mars) would indicate that they too experience a combination internal processes, low surface gravity, volcanism, and a lack of tectonic plate movement. Meanwhile, low-bumpiness planets are less likely to have any of these internal processes and their surfaces are more likely to be shaped by external factors – like asteroid bombardment.
Artist’s impression of the OWL Telescope being deployed at night from its enclosure, where it will operated during the daytime. Credit: ESO
Based on their estimates, they conclude that the various super telescopes that are scheduled to be commissioned in the coming years would be up to task. These include the ESO’s OverWhelmingly Large (OWL) Telescope, a 100-meter proposed optical and near-infrared telescope that would build on the success of the Very Large Telescope (VLT) and the upcoming Extremely Large Telescope (ELT).
Another example is the Colossus Telescope, a 74-meter optical and infrared telescope that is currently being commissioned by an international consortium. Once operational, it will be the largest telescope optimized for detecting extrasolar life and extraterrestrial civilizations.
In the past, the success of exoplanet hunters has come down to a combination of factors. In addition to greater levels of cooperation between institutions, amateur astronomers and citizen scientists, there has also been the way in which improved technology has coincided with new theoretical models. As more data become available, scientists are able to produce more educated estimates on what we might be able to learn once new instruments come online.
When the next-generation telescopes take to space or are finished construction here on Earth, we can anticipate that thousands more exoplanets will be found. At the same time, we can anticipate that important details will be also discovered about these planets that were not possible before. Do they have atmospheres? Do they have oceans? Do they have mountain ranges and chasms? We hope to find out!
Study co-author I. Altshuler sampling permafrost terrain near the McGill Arctic research station, Canadian high Arctic. Image: Dr. Jacqueline Goordial
Researchers at Canada’s McGill University have shown for the first time how existing technology could be used to directly detect life on Mars and other planets. The team conducted tests in Canada’s high arctic, which is a close analog to Martian conditions. They showed how low-weight, low-cost, low-energy instruments could detect and sequence alien micro-organisms. They presented their results in the journal Frontiers in Microbiology.
Getting samples back to a lab to test is a time consuming process here on Earth. Add in the difficulty of returning samples from Mars, or from Ganymede or other worlds in our Solar System, and the search for life looks like a daunting task. But the search for life elsewhere in our Solar System is a major goal of today’s space science. The team at McGill wanted to show that, conceptually at least, samples could be tested, sequenced, and grown in-situ at Mars or other locations. And it looks like they’ve succeeded.
Recent and current missions to Mars have studied the suitability of Mars for life. But they don’t have the ability to look for life itself. The last time a Mars mission was designed to directly search for life was in the 1970’s, when NASA’s Viking 1 and 2 missions landed on the surface. No life was detected, but decades later people still debate the results of those missions.
The Viking 2 lander captured this image of itself on the Martian surface. The Viking Landers were the last missions to directly look for life on Mars. By NASA – NASA website; description,[1] high resolution image.[2], Public Domain, https://commons.wikimedia.org/w/index.php?curid=17624
But Mars is heating up, figuratively speaking, and the sophistication of missions to Mars keeps growing. With crewed missions to Mars a likely reality in the not-too-distant future, the team at McGill is looking ahead to develop tools to search for life there. And they focused on miniature, economical, low-energy technology. Much of the current technology is too large or demanding to be useful on missions to Mars, or to places like Enceladus or Europa, both future destinations in the Search for Life.
“To date, these instruments remain high mass, large in size, and have high energy requirements. Such instruments are entirely unsuited for missions to locations such as Europa or Enceladus for which lander packages are likely to be tightly constrained.”
The team of researchers from McGill, which includes Professor Lyle Whyte and Dr. Jacqueline Goordial, have developed what they are calling the ‘Life Detection Platform (LDP).’ The platform is modular, so that different instruments can be swapped out depending on mission requirements, or as better instruments are developed. As it stands, the Life Detection Platform can culture microorganisms from soil samples, assess microbial activity, and sequence DNA and RNA.
There are already instruments available that can do what the LDP can do, but they’re bulky and require more energy to operate. They aren’t suitable for missions to far-flung destinations like Enceladus or Europa, where sub-surface oceans might harbour life. As the authors say in their study, “To date, these instruments remain high mass, large in size, and have high energy requirements. Such instruments are entirely unsuited for missions to locations such as Europa or Enceladus for which lander packages are likely to be tightly constrained.”
A key part of the system is a miniaturized, portable DNA sequencer called the Oxford Nanopore MiniON. The team of researchers behind this study were able to show for the first time that the MiniON can examine samples in extreme and remote environments. They also showed that when combined with other instruments it can detect active microbial life. The researches succeeded in isolatinh microbial extremophiles, detecting microbial activity, and sequencing the DNA. Very impressive indeed.
This image shows the instruments tested in the Life Detection Platform. Image: J. Goordial et. al.
These are early days for the Life Detection Platform. The system required hands-on operation in these tests. But it does show proof of concept, an important stage in any technological development. “Humans were required to carry out much of the experimentation in this study, while life detection missions on other planets will need to be robotic,” says Dr Goordial.
“Humans were required to carry out much of the experimentation in this study, while life detection missions on other planets will need to be robotic.” – Dr. J. Goordial
The system as it stands now is useful here on Earth. The same things that allow it to search for and sequence microorganisms on other worlds make it suitable for the same task here on Earth. “The types of analyses performed by our platform are typically carried out in the laboratory, after shipping samples back from the field,” says Dr. Goordial. This makes the system desirable for studying epidemics in remote areas, or in rapidly changing conditions where transporting samples to distant labs can be problematic.
These are very exciting times in the Search for Life in our Solar System. If, or when, we discover microbial life on Mars, Europa, Enceladus, or some other world, it will likely be done robotically, using equipment similar to the LDP.
A new study by an international team of scientists considers whether Mars and Earth formed farther away from the Sun than previously thought. Credit: NASA/JPL-Caltech/USGS
In recent years, astronomers have been looking to refine our understanding of how the Solar System formed. On the one hand, you have the traditional Nebular Hypothesis which argues that the Sun, the planets, and all other objects in the Solar System formed from nebulous material billions of years ago. However, astronomers traditionally assumed that the planets formed in their current orbits, which has since come to be questioned.
This has come to be challenged by theories like the Grand Tack model. This theory states that Jupiter migrated from its original orbit after it formed, which had a big impact on the inner Solar System. And in a more recent study, an international team of scientists have taken things a step further, proposing that Mars actually formed in what is today the Asteroid Belt and migrated closer to the Sun over time.
Composite image showing the size difference between Earth and Mars. Credit: NASA/Mars Exploration
For the sake of their study, the team addressed one of the most glaring issues with traditional models of Solar System formation. This is the assumption that Mars, Earth and Venus formed closely together and that Mars migrated outward to its current orbit. In addition, the theory holds that Mars – roughly 53% as large as Earths and only 15% as massive – is essentially a planetary embryo that never became a full, rocky planet.
However, this has contradicted by bulk elemental and isotopic studies performed on Martian meteorites, which have noted key differences in composition between Mars and Earth. As Brasser and his team indicated in their study:
“This suggests that Mars formed outside of the terrestrial feeding zone during primary accretion. It is therefore probable that Mars always remained significantly farther from the Sun than Earth; its growth was stunted early and its mass remained relatively low.”
To test this hypothesis, the team conducted dynamical simulations that were consistent with the Grand Tack model. In these simulations, Jupiter moved a large concentration of mass towards the Sun at it migrated towards the inner Solar System, which had a profound influence on the formation and orbital characteristics of the terrestrial planets (Mercury, Venus, Earth and Mars).
The theory also holds that this migration pulled material away from Mars, thus accounting for the compositional differences and the planet’s smaller size and mass relative to Venus and Earth. What they found was that in a small percentage of their simulations, Mars formed farther from the Sun and that Jupiter’s gravitational pull pushed Mars into its current orbit.
The Grand Tack model (top) compared to the traditional theories about how the Inner Solar System formed. Credit: Sean Raymond/planetplanet.net
From this, the team concluded that either scientists lack the necessary mechanisms to explain Mars’ formation, or that of all the possibilities, this statistically rare scenario is indeed the correct one. As Stephen Mojzsis – a geological sciences professor at the University of Colorado and a co-author on the study – indicated in a recent interview with Astrobiology Magazine, the fact that the scenario is rare does not make it any less plausible:
“Given enough time, we can expect these events. For example, you’ll eventually get double sixes if you roll the dice enough times. The probability is 1/36 or roughly the same as we get for our simulations of Mars’ formation.”
In truth, a 2% probability (which is what they obtained from the simulations) is hardly poor odds when considered in cosmological terms. And when one considers that such a possibility would allow for the key differences between Mars and its terrestrial cousins (i.e. Earth and Venus), this slim probability appears rather possible. However, the idea that Mars migrated inward during the course of its history also carries with it some serious implications.
For starters, the researchers were pressed to explain how Mars could have possessed a thicker, warmer atmosphere that would have allowed for liquid water to exist on the surface. If Mars actually formed in the modern-day Asteroid Belt, it would have been subject to far less solar flux, and surface temperatures would have been significantly lower than if it had formed in its present-day location.
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
However, as they go to indicate, if Mars had enough carbon-dioxide in its early atmosphere, then it is possible that impacts during the Late Heavy Bombardment could have allowed for intermittent periods where liquid water could exist on the surface. Or as they explain it:
“Unless, as our model shows, an intrinsically volatile-rich Mars possessed a strong and sustainable greenhouse atmosphere, its average surface temperature was unremittingly below 0 °C. Such a cold surface environment would have been regularly affected by early impact bombardments that both restarted a moribund hydrological cycle, and provided a haven for possible early life in the martian crust.”
Basically, while Mars would have been subject to less in the way of solar energy during its early lifespan, its possible it could have still been warm enough to support liquid water on its surface. And as Mojzsis stated in a paper he co-authored last year, the many bombardments it received (as attested to by its many craters) would have been enough to melt surface ice, thicken the atmosphere, and trigger a periodic hydrological cycle.
Another interesting thing about this study is how it predicts that Venus likely has a bulk composition (including its oxygen isotopes) that is similar to that of the Earth-Moon system. According to their simulations, this is due to the fact that Venus and Earth always shared the same building blocks, whereas Earth and Mars did not. These findings were consistent with recent ground-based infrared observations of Venus and its atmosphere.
Artist’s impression of the joint NASA-Roscosmos Venera-D mission concept, which wold include a Venus orbiter and a lander designed to survive on Venus’ surface for a few hours. Credit: NASA/JPL-Caltech
But of course, no definitive conclusions can be drawn about that until samples of Venus’ crust can be obtained. This could be accomplished if and when the proposed Venera-Dolgozhivuschaya (Venera-D) mission – a joint NASA/Roscomos plan to send a orbiter and lander to Venus – is launched in the coming decade. In the meantime, there are other outstanding issues in the Grand Tack model and Nebular Hypothesis that need to be addressed.
According to Mojzsis, these include how the gas/ice giants of the Solar System could have formed in their current locations. The idea that they formed in their current orbits beyond the Asteroid Belt seems inconsistent with models of the early Solar System, which show that there was not enough of the necessary material that far from the Sun. An alternative is that they formed closer to the Sun and also migrated outward.
As Mojzsis explained, this possibility is bolstered by recent studies of extra-solar planetary systems, where gas giants have been found to orbit very close to their stars (i.e. “Hot Jupiters”) and farther away:
“We understand from direct observations via the Kepler Space Telescope and earlier studies that giant planet migration is a normal feature of planetary systems. Giant planet formation induces migration, and migration is all about gravity, and these worlds affected each other’s orbits early on.”
If there’s one benefit to being able to look farther out into the Universe, its the way it has allowed astronomers to come up with better and more complete theories of how the Solar System came to be. And as our exploration of the Solar System continues to grow, we are sure to learn many things that will help advance our understanding of other star systems as well.
Artist’s impression of Proxima b, which was discovered using the Radial Velocity method. Credit: ESO/M. Kornmesser
Red dwarf stars have become a major focal point for exoplanet studies lately, and for good reason. For starters, M-type (red dwarf) stars are the most common type in our Universe, accounting for 75% of stars in the Milky Way alone. In addition, in the past decade, numerous terrestrial (i.e rocky) exoplanets have been discovered orbiting red dwarf stars, and within their circumstellar habitable zones (“Goldilocks Zones”) to boot.
This has naturally prompted several studies to determine whether or not rocky planets can retain their atmospheres. The latest study comes from NASA, using data obtained by the Mars Atmosphere and Volatile Evolution (MAVEN) orbiter. Having studied Mars’ atmosphere for years to determine how and when it was stripped away, the MAVEN mission is well-suited when it comes to measuring the potential habitability of other planets.
The study was shared on Dec. 13th, 2017, at the Fall Meeting of the American Geophysical Union in New Orleans, Louisiana. In a presentation titled “Spanning Disciplines to Search for Life Beyond Earth“, a team of NASA scientists and researchers from the University of California-Riverside and the University of Colorado-Boulder explained how insights from the MAVEN mission could be applied to the habitability of rocky planets orbiting other stars.
Artist’s rendering of a solar storm hitting Mars and stripping ions from the planet’s upper atmosphere. Credits: NASA/GSFC
Launched in November 18th, 2013, the MAVEN mission established orbit around Mars on September 22nd, 2014. The purpose of this mission has been to explore the Red Planet’s upper atmosphere, ionosphere and its interactions with the Sun and solar wind for the sake of determining how and when Mars’ atmosphere went from being thicker and warmer in the past (and thus able to support liquid water on the surface) to thin and tenuous today.
Since November of 2014, MAVEN has been measuring Mars’ atmospheric loss using its suite of scientific instruments. From the data it has obtained, scientists have surmised that the majority of the planet’s atmosphere was lost to space over time due to a combination of chemical and physical processes. And in the past three years, the Sun’s activity has increased and decreased, giving MAVEN the opportunity to observe how Mars’ atmospheric loss has risen and fallen accordingly.
Because of this, David Brain – a professor at the Laboratory for Atmospheric and Space Physics (LASP) at the CU Boulder is also a MAVEN co-investigator – and his colleagues began to think about how these insights could be applied to a hypothetical Mars-like planet orbiting around an red dwarf star. These planets include Proxima b (the closest exoplanet to our Solar System) and the seven planet system of TRAPPIST-1.
As Brain he explained in a recent NASA press release:
“The MAVEN mission tells us that Mars lost substantial amounts of its atmosphere over time, changing the planet’s habitability. We can use Mars, a planet that we know a lot about, as a laboratory for studying rocky planets outside our solar system, which we don’t know much about yet.”
At one time, Mars had a magnetic field similar to Earth, which prevented its atmosphere from being stripped away. Credit: NASA
To determine if this hypothetical planet could retain its atmosphere over time, the researchers performed some preliminary calculations that assumed that this planet would be positioned near the outer edge of the star’s habitable zone (as Mars is). Since red dwarf’s are dimmer than our Sun, the planet would have to orbit much closer to the star – even closer than Mercury does to our Sun – to be within this zone.
They also considered how a higher proportion of the light emanating from red dwarf stars is in the ultraviolet wavelength. Combined with a close orbit, this means that the hypothetical planet would be bombarded with about 5 times more UV radiation the real Mars gets. This would also mean that the processes responsible for atmospheric loss would be increased for this planet.
Based on data obtained by MAVEN, Brain and colleagues were able to estimate how this increase in radiation would affect Mars’ own atmospheric loss. Based on their calculations, they found that the planet’s atmosphere would lose 3 to 5 times as many charged particles through ion escape, while about 5 to 10 times more neutral particles would be lost through photochemical escape (where UV radiaion breaks apart molecules in the upper atmosphere).
Another form of atmospheric loss would also result, due to the fact that more UV radiation means that more charged particles would be created. This would result in a process called “sputtering”, where energetic particles are accelerated into the atmosphere and collide with other molecules, kicking some out into space and sending others crashing into neighboring particles.
To receive the same amount of starlight as Mars receives from our Sun, a planet orbiting an M-type red dwarf would have to be positioned much closer to its star than Mercury is to the Sun. Credit: NASA’s Goddard Space Flight Center
Lastly, they considered how the hypothetical planet might experience about the same amount of thermal escape (aka. Jeans escape) as the real Mars. This process occurs only for lighter molecules such as hydrogen, which Mars loses at the top of its atmosphere through thermal escape. On the “exo-Mars”, however, thermal escape would increase only if the increase in UV radiation were to push more hydrogen into the upper atmosphere.
In conclusion, the researchers determined that orbiting at the edge of the habitable zone of a quiet M-type star (instead of our Sun) could shorten the habitable period for a Mars-like planet by a factor of about 5 to 20. For a more active M-type star, the habitable period could be cut by as much as 1,000 times. In addition, solar storm activity around a red dwarf, which is thousands of times more intense than with our Sun, would also be very limiting.
However, the study is based on how an exo-Mars would fair around and M-type star, which kind of stacks the odds against habitability in advance. When different planets are considered, which possess mitigating factors Mars does not, things become a bit more promising. For instance, a planet that is more geologically active than Mars would be able to replenish its atmosphere at a greater rate.
Other factors include increase mass, which would allow for the planet to hold onto more of its atmosphere, and the presence of a magnetic field to shield it from stellar wind. As Bruce Jakosky, MAVEN’s principal investigator at the University of Colorado (who was not associated with this study), remarked:
“Habitability is one of the biggest topics in astronomy, and these estimates demonstrate one way to leverage what we know about Mars and the Sun to help determine the factors that control whether planets in other systems might be suitable for life.”
Multiple survey have revealed evidence of rocky planets orbiting a red dwarf stars, raising questions about their habitability. Credit: ESO/M. Kornmesser/N. Risinger (skysurvey.org).
In the coming years, astronomers and exoplanet researchers hope to learn more about the planets orbiting nearby red dwarf stars. These efforts are expected to be helped immensely thanks to the deployment of the James Webb Space Telescope, which will be able to conduct more detailed surveys of these star systems using its advanced infrared imaging capabilities.
These studies will allow scientists to place more accurate constraints on exoplanets that orbit red dwarf stars, which will allow for better estimates about their size, mass, and compositions – all of which are crucial to determining potential habitability.
Other panelists that took part in the presentations included Giada Arney and Katherine Garcia-Sage of NASA Goddard Space Flight Center and Stephen Kane of the University of California-Riverside. You can access the press conference materials by going to NASA Goddard Media Studios.
Scientists from the OU have discovered a new phenomenon that could explain the long-debated mystery of how recent land features on Mars are formed in the absence of significant amounts of water. Credit: OUNews
Mars modern landscape is something of a paradox. It’s many surface features are very similar to those on Earth that are caused by water-borne erosion. But for the life of them, scientists cannot imagine how water could have flown on Mars’ cold and desiccated surface for most of Mars’ history. Whereas Mars was once a warmer, wetter place, it has had a very thin atmosphere for billions of years now, which makes water flow and erosion highly unlikely.
In fact, while the surface of Mars periodically becomes warm enough to allow for ice to thaw, liquid water would boil once exposed to the thin atmosphere. However, in a new study led by an international team of researchers from the UK, France and Switzerland, it has been determined that a different kind of transport process involving the sublimation of water ice could have led to the Martian landscape becoming what it is today.
The study, which was led Dr. Jan Raack – a Marie Sklodowska-Curie Research Fellow at The Open University – was recently published in the scientific journal Nature Communications. Titled “Water Induced Sediment Levitation Enhances Downslope Transport on Mars”, this research study consisted of experiments that tested how processes on Mars’ surface could allow water transport without it being in liquid form.
Reull Vallis, the river-like structure captured by the ESA’s Mars Express probe, is believed to have formed when running water flowed in the distant martian past. Credit and copyright: ESA/DLR/FU Berlin (G. Neukum)
To conduct their experiments, the team used the Mars Simulation Chamber, an instrument at The Open University that is capable of simulating the atmospheric conditions on Mars. This involved lowering the atmospheric pressure inside the chamber to what is normal for Mars – about 7 mbar, compared to 1000 mbar (1 bar or 100 kilopascals) here on Earth – while also adjusting temperatures.
On Mars, temperatures range from a low of -143 °C (-255 °F) during winter at the poles to a high of 35 °C (95 °F) at the equator during midday in the summer. Having recreated these conditions, the team found that when water ice exposed to the simulated Martian atmosphere, it would not simply melt. Instead, it would become unstable and begin violently boiling off.
However, the team also found that this process would be capable of moving large amounts of sand and sediment, which would effectively “levitate” on the boiling water. This means that, compared to Earth, relatively small amounts of liquid water are capable of moving sediment across the surface of Mars. These levitating pockets of sand and debris would be capable of forming tje large dunes, gullies, recurring slope lineae, and other features observed on Mars.
In the past, scientists have indicated how these features were the result of sediment transportation down slopes, but were unclear as to the mechanisms behind them. As Dr. Jan Raack explained in a OUNews press release:
“Our research has discovered that this levitation effect caused by boiling water under low pressure enables the rapid transport of sand and sediment across the surface. This is a new geological phenomenon, which doesn’t happen on Earth, and could be vital to understanding similar processes on other planetary surfaces.”
Illustration of the ESA Exomars 2020 Rover, which will explore the Red Planet in search for signs of ancient life. Credit:ESA
Through these experiments, Dr. Raack and his colleagues were able to shed light on how conditions on Mars could allow for features that we tend to associate with flowing water here on Earth. In addition to helping to resolve a somewhat contentious debate concerning Mars’ geological history and evolution, this study is also significant when it comes to future exploration missions.
Dr. Raack acknowledges the need for more research to confirm their study’s conclusions, and indicated that the ESA’s ExoMars 2020 Rover will be well-situated to conduct it once it is deployed :
“This is a controlled laboratory experiment, however, the research shows that the effects of relatively small amounts of water on Mars in forming features on the surface may have been widely underestimated. We need to carry out more research into how water levitates on Mars, and missions such as the ESA ExoMars 2020 Rover will provide vital insight to help us better understand our closest neighbour.”
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NASA’s Curiosity rover raised robotic arm with drill pointed skyward while exploring Vera Rubin Ridge at the base of Mount Sharp inside Gale Crater - backdropped by distant crater rim. This navcam camera mosaic was stitched from raw images taken on Sol 1833, Oct. 2, 2017 and colorized. Credit: NASA/JPL/Ken Kremer/kenkremer.com/Marco Di Lorenzo
NASA’s Curiosity rover raised robotic arm with drill pointed skyward while exploring Vera Rubin Ridge at the base of Mount Sharp inside Gale Crater – backdropped by distant crater rim. This navcam camera mosaic was stitched from raw images taken on Sol 1833, Oct. 2, 2017 and colorized. Credit: NASA/JPL/Ken Kremer/kenkremer.com/Marco Di Lorenzo
5 years after a heart throbbing Martian touchdown, Curiosity is climbing Vera Rubin Ridge in search of “aqueous minerals” and “clays” for clues to possible past life while capturing “truly breathtaking” vistas of humongous Mount Sharp – her primary destination – and the stark eroded rim of the Gale Crater landing zone from ever higher elevations, NASA scientists tell Universe Today in a new mission update.
“Curiosity is doing well, over five years into the mission,” Michael Meyer, NASA Lead Scientist, Mars Exploration Program, NASA Headquarters told Universe Today in an interview.
“A key finding is the discovery of an extended period of habitability on ancient Mars.”
The car-sized rover soft landed on Mars inside Gale Crater on August 6, 2012 using the ingenious and never before tried “sky crane” system.
A rare glimpse of Curiosity’s arm and turret mounted skyward pointing drill is illustrated with our lead mosaic from Sol 1833 of the robot’s life on Mars – showing a panoramic view around the alien terrain from her current location in October 2017 while actively at work analyzing soil samples.
“Your mosaic is absolutely gorgeous!’ Jim Green, NASA Director Planetary Science Division, NASA Headquarters, Washington D.C., told Universe Today
“We are at such a height on Mt Sharp to see the rim of Gale Crater and the top of the mountain. Truly breathtaking.”
The rover has ascended more than 300 meters in elevation over the past 5 years of exploration and discovery from the crater floor to the mountain ridge. She is driving to the top of Vera Rubin Ridge at this moment and always on the lookout for research worthy targets of opportunity.
Additionally, the Sol 1833 Vera Rubin Ridge mosaic, stitched by the imaging team of Ken Kremer and Marco Di Lorenzo, shows portions of the trek ahead to the priceless scientific bounty of aqueous mineral signatures detected by spectrometers years earlier from orbit by NASA’s fleet of Red Planet orbiters.
NASA’s Curiosity rover as seen simultaneously on Mars surface and from orbit on Sol 1717, June 5, 2017. The robot snapped this self portrait mosaic view while approaching Vera Rubin Ridge at the base of Mount Sharp inside Gale Crater – backdropped by distant crater rim. This navcam camera mosaic was stitched from raw images and colorized. Inset shows overhead orbital view of Curiosity (blue feature) amid rocky mountainside terrain taken the same day by NASA’s Mars Reconnaissance Orbiter. Credit: NASA/JPL/Ken Kremer/kenkremer.com/Marco Di Lorenzo
“Curiosity is on Vera Rubin Ridge (aka Hematite Ridge) – it is the first aqueous mineral signature that we have seen from space, a driver for selecting Gale Crater,” NASA HQ Mars Lead Scientist Meyer elaborated.
“And now we have access to it.”
The Sol 1833 photomosaic illustrates Curiosity maneuvering her 7 foot long (2 meter) robotic arm during a period when she was processing and delivering a sample of the “Ogunquit Beach” for drop off to the inlet of the CheMin instrument earlier in October. The “Ogunquit Beach” sample is dune material that was collected at Bagnold Dune II this past spring.
The sample drop is significant because the drill has not been operational for some time.
“Ogunquit Beach” sediment materials were successfully delivered to the CheMin and SAM instruments over the following sols and multiple analyses are in progress.
To date three CheMin integrations of “Ogunquit Beach” have been completed. Each one brings the mineralogy into sharper focus.
Researchers used the Mastcam on NASA’s Curiosity Mars rover to gain this detailed view of layers in “Vera Rubin Ridge” from just below the ridge. The scene combines 70 images taken with the Mastcam’s right-eye, telephoto-lens camera, on Aug. 13, 2017. Credit: NASA/JPL-Caltech/MSSS
What’s the status of the rover health at 5 years, the wheels and the drill?
“All the instruments are doing great and the wheels are holding up,” Meyer explained.
“When 3 grousers break, 60% life has been used – this has not happened yet and they are being periodically monitored. The one exception is the drill feed (see detailed update below).”
NASA’s Curiosity rover explores sand dunes inside Gale Crater with Mount Sharp in view on Mars on Sol 1611, Feb. 16, 2017, in this navcam camera mosaic, stitched from raw images and colorized. Credit: NASA/JPL/Ken Kremer/kenkremer.com/Marco Di Lorenzo
NASA’s 1 ton Curiosity Mars Science Laboratory (MSL) rover is now closer than ever to the mineral signatures that were the key reason why Mount Sharp was chosen as the robots landing site years ago by the scientists leading the unprecedented mission.
Along the way from the ‘Bradbury Landing’ zone to Mount Sharp, six wheeled Curiosity has often been climbing. To date she has gained over 313 meters (1027 feet) in elevation – from minus 4490 meters to minus 4177 meters today, Oct. 19, 2017, said Meyer.
The low point was inside Yellowknife Bay at approx. minus 4521 meters.
VRR alone stands about 20 stories tall and gains Curiosity approx. 65 meters (213 feet) of elevation to the top of the ridge. Overall the VRR traverse is estimated by NASA to take drives totaling more than a third of a mile (570 m).
Curiosity images Vera Rubin Ridge during approach backdropped by Mount Sharp. This navcam camera mosaic was stitched from raw images taken on Sol 1726, June 14, 2017 and colorized. Credit: NASA/JPL/Marco Di Lorenzo/Ken Kremer/kenkremer.com
“Vera Rubin Ridge” or VRR is also called “Hematite Ridge.” It’s a narrow and winding ridge located on the northwestern flank of Mount Sharp. It was informally named earlier this year in honor of pioneering astrophysicist Vera Rubin.
The intrepid robot reached the base of the ridge in early September.
The ridge possesses steep cliffs exposing stratifications of large vertical sedimentary rock layers and fracture filling mineral deposits, including the iron-oxide mineral hematite, with extensive bright veins.
VRR resists erosion better than the less-steep portions of the mountain below and above it, say mission scientists.
Curiosity rover raises robotic arm high while scouting the Bagnold Dune Field and observing dust devils inside Gale Crater on Mars on Sol 1625, Mar. 2, 2017, in this navcam camera mosaic stitched from raw images and colorized. Note: Wheel tracks at right, distant crater rim in background. Credit: NASA/JPL/Ken Kremer/kenkremer.com/Marco Di Lorenzo
What’s ahead for Curiosity in the coming weeks and months exploring VRR before moving onward and upwards to higher elevation?
“Over the next several months, Curiosity will explore Vera Rubin Ridge,” Meyer replied.
“This will be a big opportunity to ground-truth orbital observations. Of interest, so far, the hematite of VRR does not look that different from what we have been seeing all along the Murray formation. So, big question is why?”
“The view from VRR also provides better access to what’s ahead in exploring the next aqueous mineral feature – the clay, or phyllosilicates, which can be indicators of specific environments, putting constraints on variables such as pH and temperature,” Meyer explained.
The clay minerals or phyllosilicates form in more neutral water, and are thus extremely scientifically interesting since pH neutral water is more conducive to the origin and evolution of Martian microbial life forms, if they ever existed.
How far away are the clays ahead and when might Curiosity reach them?
“As the crow flies, the clays are about 0.5 km,” Meyer replied. “However, the actual odometer distance and whether the clays are where we think they are – area vs. a particular location – can add a fair degree of variability.”
The clay rich area is located beyond the ridge.
Over the past few months Curiosity make rapid progress towards the hematite-bearing location of Vera Rubin Ridge after conducting in-depth exploration of the Bagnold Dunes earlier this year.
“Vera Rubin Ridge is a high-standing unit that runs parallel to and along the eastern side of the Bagnold Dunes,” said Mark Salvatore, an MSL Participating Scientist and a faculty member at Northern Arizona University, in a mission update.
“From orbit, Vera Rubin Ridge has been shown to exhibit signatures of hematite, an oxidized iron phase whose presence can help us to better understand the environmental conditions present when this mineral assemblage formed.”
Curiosity is using the science instruments on the mast, deck and robotic arm turret to gather detailed research measurements with the cameras and spectrometers. The pair of miniaturized chemistry lab instruments inside the belly – CheMin and SAM – are used to analyze the chemical and elemental composition of pulverized rock and soil gathered by drilling and scooping selected targets during the traverse.
A key instrument is the drill which has not been operational. I asked Meyer for a drill update.
“The drill feed developed problems retracting (two stabilizer prongs on either side of the drill retract, controlling the rate of drill penetration),” Meyer replied.
“Because the root cause has not been found (think FOD) and the concern about the situation getting worse, the drill feed has been retracted and the engineers are working on drilling without the stabilizing prongs.”
“Note, a consequence is that you can still drill and collect sample but a) there is added concern about getting the drill stuck and b) a new method of delivering sample needs to be developed and tested (the drill feed normally needs to be moved to move the sample into the chimera). One option that looks viable is reversing the drill – it does work and they are working on the scripts and how to control sample size.”
Ascending and diligently exploring the sedimentary lower layers of Mount Sharp, which towers 3.4 miles (5.5 kilometers) into the Martian sky, is the primary destination and goal of the rover’s long term scientific expedition on the Red Planet.
“Lower Mount Sharp was chosen as a destination for the Curiosity mission because the layers of the mountain offer exposures of rocks that record environmental conditions from different times in the early history of the Red Planet. Curiosity has found evidence for ancient wet environments that offered conditions favorable for microbial life, if Mars has ever hosted life,” says NASA.
Stay tuned. In part 2 we’ll discuss the key findings from Curiosity’s first 5 years exploring the Red Planet.
As of today, Sol 1850, Oct. 19, 2017, Curiosity has driven over 10.89 miles (17.53 kilometers) since its August 2012 landing inside Gale Crater from the landing site to the ridge, and taken over 445,000 amazing images.
Stay tuned here for Ken’s continuing Earth and planetary science and human spaceflight news.
Map shows route driven by NASA’s Mars rover Curiosity through Sol 1827 of the rover’s mission on Mars (September 27, 2017). Numbering of the dots along the line indicate the sol number of each drive. North is up. Since touching down in Bradbury Landing in August 2012, Curiosity has driven 10.84 miles (17.45 kilometers). The base image from the map is from the High Resolution Imaging Science Experiment Camera (HiRISE) in NASA’s Mars Reconnaissance Orbiter. Credit: NASA/JPL/UACuriosity’s Traverse Map Through Sol 1717. This map shows the route driven by NASA’s Mars rover Curiosity through the 1717 Martian day, or sol, of the rover’s mission on Mars (June 05, 2017). The base image from the map is from the High Resolution Imaging Science Experiment Camera (HiRISE) in NASA’s Mars Reconnaissance Orbiter. Credit: NASA/JPL-Caltech/Univ. of Arizona
![The Viking 2 lander captured this image of itself on the Martian surface. The Viking Landers were the last missions to directly look for life on Mars. By NASA - NASA website; description,[1] high resolution image.[2], Public Domain, https://commons.wikimedia.org/w/index.php?curid=17624](https://www.universetoday.com/wp-content/uploads/2016/10/608px-Viking2lander1-580x458.jpg)
