Europe’s Mars rover takes shape

So, here it is. Europe’s Mars rover. Or rather, a copy of it.

This is what they call the Structural Thermal Model, or STM. It is one of three rovers that will be built as part of the European Space Agency’s ExoMars 2020 mission to search for life on the Red Planet. And, no, we’re not sending all three to the Red Planet.

The STM is used to prove the design. It will go through a tough testing regime to check the rover that does launch to Mars – the “flight model” – will be able to cope with whatever is thrown at it.

What’s the third robot for? It stays on Earth and is used to troubleshoot any problems. If mission control needs to re-write a piece of software to overcome some glitch on the flight rover, the patch will be trialled first on the “engineering model” before being sent up to the Red Planet.

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  • Mars probe despatched on methane quest
  • ExoMars rover gets second site option
  • Sky At Night: Mars – Red and Dead?

    It’s getting real, then. After all the delays and arguments, the ExoMars hardware is at last taking shape.

    The STM, which has been assembled at the Airbus factory in Stevenage in the UK, is about to be boxed up and sent to a facility in Toulouse for environmental testing.

    “We’re going to ‘shake and bake’ it to demonstrate that the rover can survive all of the vibrations and acoustic loading during the rocket launch, all of the shocks of deployment, and then all of the thermal stresses it will experience – all the highs and lows – both when it’s in deep space and on the surface,” explained engineer Abbie Hutty.

    “This is where we qualify our design, proving that it meets the requirements.”

    Esa member states will meet on 8 May for the Critical Design Review. This will consider every aspect of the venture and is really the last chance to change some aspect of the mission. There may be some tinkering at the edges, but the broad scope will not alter.

    There have been recent difficulties related to the “Analytical Drawer”, which will hold ExoMars’ life-seeking instruments. A leak was found in the test model for this box and a membrane also failed. “But, OK, this is why you do testing,” said ExoMars project scientist Jorge Vago.

    “Overall, I think we’re on a good track to complete everything we need to do. We have margin. It could be better, but we’re not working double shifts and on weekends, which is what you see on most projects towards the end.”

    ExoMars is a joint venture with the Russians. They’re building the descent module – the mechanism that gets the rover down to the surface once it enters the planet’s atmosphere.

    A structural model of this system is also in production, and when the rover STM completes its Toulouse exams, the two will have a fit check in Moscow and undergo another round of testing as a combined unit.

    A couple of developments in the rover’s capabilities are worth reporting. It’s now been confirmed the robot will be able to wheel-walk.

    This is a driving mode that sees the vehicle lift up its wheels and take steps – as opposed to just rolling forward. It would allow ExoMars to tip-toe out of a sand trap, if it gets caught in one. Nasa’s Spirit rover was snared in this way and the mission lost as a consequence.

    Wheel-walking was in the initial spec for ExoMars and then withdrawn for cost reasons. I’m pleased to report that member states have found the money to put it back on the rover.

    The other key capability that needs a similar response is autonomous navigation. This self-driving system would permit the robot to plot its own path across the surface of Mars, independently avoiding hazards such as large rocks and trenches.

    Without it, controllers back on Earth have to direct every move, and that’s a very slow process.

    “Clearly we need it, otherwise we will pay a high price in terms of the science you can do,” Dr Vago said.

    “To give you an example – if we need to move 500m, with autonomous navigation we can do that in five days. Without it, the drive might take 15 days.”

    Whether the rover gets this smart upgrade is probably going to depend on the UK and French space agencies.

    They’re the parties most interested in the technology and will have to fund it.

    Fortunately, autonomous navigation is a software complement, so even though hardware choices have to be locked down now there is still some extra time to resolve this particular issue.

    If you’re wondering where ExoMars will be sent, the decision will be made in November. Scientists will meet at Leicester University to choose between two equatorial locations, known as Oxia Planum and Mawrth Vallis.

    They’re both areas rich in clay minerals – the kinds of sediments that must have formed during prolonged rock interactions with water.

    Jonathan.Amos-INTERNET@bbc.co.uk and follow me on Twitter: @BBCAmos

Space agencies aim to deliver rocks from Mars to Earth

The US and European space agencies are edging towards a joint mission to bring back rock and soil samples from Mars.

Nasa and Esa have signed a letter of intent that could lead to the first “round trip” to another planet.

The move was announced as a meeting in Berlin, Germany, discussed the science goals and feasibility of a Mars Sample Return (MSR) mission.

The venture would allow scientists to answer key questions about Martian history.

Those questions include whether the Red Planet once hosted life.

Scientists at the Mars meeting said that there was only so much they could learn from Martian meteorites and from the various rovers and static landers sent to the Red Planet.

The next step had to be a mission that would retrieve samples from the Martian surface, blast them into space in a capsule and land them safely on Earth.

  • Europe’s Mars rover takes shape
  • Probe despatched on methane quest

    They could then be subjected to detailed analysis in laboratories, using instruments that are too big and power-hungry to carry as part of a robotic rover’s payload and techniques that are difficult to perform from 55 million kilometres away.

    Making the announcement at the ILA Berlin Air and Space Show, which is taking place at the same time as the Mars science meeting, Dr Thomas Zurbuchen, Nasa’s associate administrator for science, said: “We want to partner with the European Space Agency, but also with other partners.”

    He said this included potential link-ups with the commercial space sector, adding: “We will at every point look at what is available in the commercial market. Nasa has no interest whatsoever in developing things that we can buy.”

    Dave Parker, director of human and robotic exploration at Esa, commented: “It’s very important that every mission we send to Mars discovers something slightly unusual. It’s on the basis of that that we tend to plan the next mission or next missions.”

    Nasa’s 2020 rover mission is expected to help pave the way for Mars Sample Return, by drilling into the surface and caching the cores in containers. But this is intended as a demonstration.

    A mission design would need to be drawn up in coming years. Previous sample return concepts envisaged a rover storing geological samples from scientifically desirable locations on Mars.

    The cached samples would then be loaded on to an ascent vehicle which would lift off from the Martian surface. After the cruise back to Earth, a descent module would parachute down through Earth’s atmosphere, delivering the first retrieved Martian samples directly into the hands of experts waiting on the ground.

    Dr Caroline Smith, head of Earth sciences collections at London’s Natural History Museum, is attending the Berlin meeting. “I would say it’s a reinvigoration of the process,” she told BBC News.

    “Numerous studies have said the only way it’s going to be achieved is through international co-operation. So I think this is a really good message from Nasa and Esa, that we are really going to work together to achieve this – the next frontier of exploration of the Solar System.”

    She added: “There’s a real buzz in the room. I’ve spoken to my colleagues and they’ve said: ‘Wow, we’re really going to do this’!”

    Protecting the planet

    If life existed in the past on the Red Planet, it would likely have been microbial in nature. Scientists want to first know whether conditions were right for life to get started in the past and, if so, whether evidence of fossil microbes remains. They also want to resolve whether there’s life on the Red Planet now. “We’ll only be able to conclusively answer those questions by bringing samples back,” she explained.

    The current high levels of cosmic radiation on Mars’ surface – a consequence of its thin atmosphere – would create a hostile environment for any organisms. But there are ways life might be able to cling on. The possibility that organisms live in the Martian subsurface today means the mission would be subject to strict quarantine, or “planetary protection”, measures.

    “We have to be careful we’re not contaminating Mars with material from our planet, and we want to make sure we’re not accidentally contaminating the samples in a way that would interfere with experiments we want to do on Earth,” explained Dr Smith. She added: “If there’s something hazardous on Mars, we don’t want to accidentally release that into Earth’s biosphere.

    “We are used to handling hazardous materials, whether they be biological or nuclear. There are technologies that exist to be able to handle these in a safe way.”

    Dr Zurbuchen said the sample return mission could also be crucial for later planned human exploration of Mars, which he said Nasa should start thinking about in the 2030s.

    “I can imagine a lot of scenarios where the samples are actually critical for how we explore as humans,” he said.

    For example, scientists want to sample dust from both the atmosphere and soil, because it could have an important impact. If future human “bases” were to rely on solar cells, atmospheric dust might block out sunlight – hampering electricity generation.

    It might also cause problems inside the crew habitats. Dr Smith commented: “If that dust is ubiquitous, and gets everywhere and you’ve got people living there who are breathing in the dust, is it going to be a potential hazard to astronauts?”

    While rocks relevant to the life question are an obvious target for sample return, igneous rocks formed by magma from Mars’ interior are also on the wish-list. “By collecting igneous rocks, we get to understand the geochemical evolution of the planet Mars, we get to know when lavas were being erupted,” said Caroline Smith.

    Analysis of these rocks could help provide a much more accurate chronology for the Red Planet, which currently relies in part on values worked out from studies of the Moon.

    In 2009, Nasa and Esa agreed to collaborate on the Mars Joint Exploration Initiative, which would have culminated in the recovery of samples in the 2020s. But in 2011, Nasa cancelled its participation amid a budgetary squeeze.

    The 2nd International Mars Sample Return Conference is taking place from 25-27 April 2018 in Berlin.

    Follow Paul on Twitter.

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Curiosity rover: 2,000 days on Mars

Nasa’s Curiosity rover, also known as the Mars Science Laboratory (MSL), is celebrating 2,000 martian days (sols) investigating Gale Crater on the Red Planet. In that time, the robot has made some remarkable observations. Here are just a few of them, chosen by the Curiosity science team.

Looking back: In the history of the space age, some of the most dramatic planetary images ever taken have been of Earth, but photographed looking back from deep space. This image by Mastcam on the Curiosity Rover shows our planet as a faint pinpoint of light in the martian night sky. Every day scientists from across the world drive the Curiosity rover and study the Red Planet about 100 million miles from Earth.

The beginning: The first image that Curiosity took came back just 15 minutes after landing on 5 August 2012. Getting our imagery and other data relies on the timing of Mars Reconnaissance Orbiter (MRO) overpasses, a pattern which determines the structure of the martian working day, or sol. It shows a grainy Front Hazard Camera image – the team normally use these to help avoid obstacles – of our ultimate goal Mount Sharp. When this image came back we knew it was going to be a successful mission.

River pebbles: Once we had started driving (16 sols after landing), we soon came across these pebble beds. The rounded shape of the clasts shows that they formed in an ancient, shallow river, flowing from the surrounding four-billion-year-old highlands into Gale Crater. The inset Mastcam image shows one of the pebbles in close-up. Contrary to our expectations before MSL, the crust being eroded by the rivers was not all dark, primitive basalt but a more evolved composition and mineralogy. Pebbles caught up in this ancient martian river are causing us to rethink our view of how the underlying igneous crust and mantle of Mars formed.

Ancient lake: Before landing and in the early part of the mission, the team wasn’t sure what all of the terrains identified from MRO HiRISE orbital imagery were. They might have been lava flows or lake sediments, without close-up “ground truth” it was impossible to be certain. This image settled the debate and was a seminal stage in Martian exploration. Yellowknife Bay is made of layers of fine grained sand and muds, which were deposited as rivers flowed into an ancient Gale Crater lake. We made our first of 16 drill holes on sol 182 – we do this to get rock in to the spectrometers housed in the body of our rover – here at the John Klein site. The results – including identifying clays, organics and nitrogen-bearing compounds – showed us that this had been a habitable environment for microbial life. The next discovery step – Was There Life? – remains to be determined.

Deep water: The Pahrump Hills section Curiosity encountered around sol 753 was key for developing our understanding of Gale’s past environment. Here the rover observed thinly layered mudstones, which represented mud particles settling out from suspension within the deeper lake. The Gale Lake has been a long-standing, deep body of water.

An unconformity: At Mount Stimson, the rover identified from sol 980 a thick sandstone unit overlying the lake deposits, separated by a geological feature called an unconformity. This unconformity represents a time where erosive processes took over after millions of years when the lake had finally dried up – to form a new land surface. This shows evidence of events happening over “deep time”, similar to those that the pioneering geologist James Hutton described in his field work in the late 18th Century at Siccar Point on the Scottish Coast.

Desert sands: The Namib dunes encountered close up by Curiosity at sol 1192 is a small part of the great Bagnold dune field. Its the first active dunefield explored on the surface of another planet and Curiosity had to pick its way carefully along and through the field as moving sands are an obstacle for rovers. Although the Martian atmosphere is a fraction of the density of that of Earth’s, it is still capable of transporting sediment and is capable of creating such beautiful structures akin to those we see in the deserts of Earth.

Wind sculptures: The Murray Buttes, photographed by Mastcam on sol 1448, formed of the same sandstones observed at Mount Stimson and represent a lithified dune field created by dunes similar to those in the present day Bagnold dune field. These desert-formed sandstones sit above an unconformity, and this suggests that after a long period with a humid climate, the climate became drier and wind became the dominant agent shaping the environment at Gale Crater.

Dried muds: Curiosity is able to perform detailed analyses of the Gale rocks with the ChemCam laser and telescope mounted on its mast. Here on sol 1555 at Schooner Head we came across a set of ancient mudcracks and sulphate veins. On Earth, lakes typically dry up in places around their margins and here on Mars the Gale lake was no different. You can see the red crosses where we fired the laser at the rock, creating a small plasma spark, with the wavelength of light in the spark telling us the composition of the mudstone and veins.

Cloudy skies: This sequence of images was taken with Curiosity’s Navigational Cameras (NavCam) on sol 1971 as we pointed them towards the sky. Occasionally on the cloudiest of Martian days we are able to make out faint clouds in the sky. These images are processed to highlight differences, allowing us to see the clouds move across the sky. This sequence shows previously unseen cloud features with prominent zig-zag patterns visible. The three images, from start to finish, cover approximately 12 minutes on Mars.

Obligatory ‘selfie’: The Curiosity rover has gained a reputation over the years that rivals those of Instagram users for its many “selfies” taken along its traverse. These selfies are not all for show though as they help the team track the state of the rover throughout the course of the mission for changes such as wheel wear and dust accumulation. Curiosity’s self-portraits are taken using the rover’s Mars Hand Lens Imager (MAHLI) situated on its robotic arm and are generated by merging a series of high-resolution images into a mosaic. This one taken on sol 1065 at the Buckskin locality shows the main mast of Curiosity with its ChemCam telescope used to determine rock compositions, and the Mastcam cameras. In the foreground you can see that Curiosity has just been drilling, leaving a small grey pile of tailings.

Long drive: This panorama taken with the rover’s Mastcam shows Curiosity’s 18.4km drive over the last 5 years from the Bradbury landing site to its current location on the Vera Rubin Ridge (VRR). VRR was formerly known as Hematite Ridge due to the high concentrations of the iron oxide mineral hematite detected here from orbit. As hematite largely forms in the presence of water, this location was a high-priority target for the Curiosity rover science team to investigate in order to assess how the conditions in Gale Crater changed over its geological history. This key location is the perfect spot for Curiosity to spend its 2000th sol, and for all of us to look back on the many discoveries made so far in the mission.

By John Bridges, Ashwin Vasavada, Susanne Schwenzer, Sanjeev Gupta, Steve Banham, Candice Bedford, Christina Smith, Brittney Cooper & the MSL Team

Curiosity rover: 2,000 days on Mars

Nasa’s Curiosity rover, also known as the Mars Science Laboratory (MSL), is celebrating 2,000 martian days (sols) investigating Gale Crater on the Red Planet. In that time, the robot has made some remarkable observations. Here are just a few of them, chosen by the Curiosity science team.

Looking back: In the history of the space age, some of the most dramatic planetary images ever taken have been of Earth, but photographed looking back from deep space. This image by Mastcam on the Curiosity Rover shows our planet as a faint pinpoint of light in the martian night sky. Every day scientists from across the world drive the Curiosity rover and study the Red Planet about 100 million miles from Earth.

The beginning: The first image that Curiosity took came back just 15 minutes after landing on 5 August 2012. Getting our imagery and other data relies on the timing of Mars Reconnaissance Orbiter (MRO) overpasses, a pattern which determines the structure of the martian working day, or sol. It shows a grainy Front Hazard Camera image – the team normally use these to help avoid obstacles – of our ultimate goal Mount Sharp. When this image came back we knew it was going to be a successful mission.

River pebbles: Once we had started driving (16 sols after landing), we soon came across these pebble beds. The rounded shape of the clasts shows that they formed in an ancient, shallow river, flowing from the surrounding four-billion-year-old highlands into Gale Crater. The inset Mastcam image shows one of the pebbles in close-up. Contrary to our expectations before MSL, the crust being eroded by the rivers was not all dark, primitive basalt but a more evolved composition and mineralogy. Pebbles caught up in this ancient martian river are causing us to rethink our view of how the underlying igneous crust and mantle of Mars formed.

Ancient lake: Before landing and in the early part of the mission, the team wasn’t sure what all of the terrains identified from MRO HiRISE orbital imagery were. They might have been lava flows or lake sediments, without close-up “ground truth” it was impossible to be certain. This image settled the debate and was a seminal stage in Martian exploration. Yellowknife Bay is made of layers of fine grained sand and muds, which were deposited as rivers flowed into an ancient Gale Crater lake. We made our first of 16 drill holes on sol 182 – we do this to get rock in to the spectrometers housed in the body of our rover – here at the John Klein site. The results – including identifying clays, organics and nitrogen-bearing compounds – showed us that this had been a habitable environment for microbial life. The next discovery step – Was There Life? – remains to be determined.

Deep water: The Pahrump Hills section Curiosity encountered around sol 753 was key for developing our understanding of Gale’s past environment. Here the rover observed thinly layered mudstones, which represented mud particles settling out from suspension within the deeper lake. The Gale Lake has been a long-standing, deep body of water.

An unconformity: At Mount Stimson, the rover identified from sol 980 a thick sandstone unit overlying the lake deposits, separated by a geological feature called an unconformity. This unconformity represents a time where erosive processes took over after millions of years when the lake had finally dried up – to form a new land surface. This shows evidence of events happening over “deep time”, similar to those that the pioneering geologist James Hutton described in his field work in the late 18th Century at Siccar Point on the Scottish Coast.

Desert sands: The Namib dunes encountered close up by Curiosity at sol 1192 is a small part of the great Bagnold dune field. Its the first active dunefield explored on the surface of another planet and Curiosity had to pick its way carefully along and through the field as moving sands are an obstacle for rovers. Although the Martian atmosphere is a fraction of the density of that of Earth’s, it is still capable of transporting sediment and is capable of creating such beautiful structures akin to those we see in the deserts of Earth.

Wind sculptures: The Murray Buttes, photographed by Mastcam on sol 1448, formed of the same sandstones observed at Mount Stimson and represent a lithified dune field created by dunes similar to those in the present day Bagnold dune field. These desert-formed sandstones sit above an unconformity, and this suggests that after a long period with a humid climate, the climate became drier and wind became the dominant agent shaping the environment at Gale Crater.

Dried muds: Curiosity is able to perform detailed analyses of the Gale rocks with the ChemCam laser and telescope mounted on its mast. Here on sol 1555 at Schooner Head we came across a set of ancient mudcracks and sulphate veins. On Earth, lakes typically dry up in places around their margins and here on Mars the Gale lake was no different. You can see the red crosses where we fired the laser at the rock, creating a small plasma spark, with the wavelength of light in the spark telling us the composition of the mudstone and veins.

Cloudy skies: This sequence of images was taken with Curiosity’s Navigational Cameras (NavCam) on sol 1971 as we pointed them towards the sky. Occasionally on the cloudiest of Martian days we are able to make out faint clouds in the sky. These images are processed to highlight differences, allowing us to see the clouds move across the sky. This sequence shows previously unseen cloud features with prominent zig-zag patterns visible. The three images, from start to finish, cover approximately 12 minutes on Mars.

Obligatory ‘selfie’: The Curiosity rover has gained a reputation over the years that rivals those of Instagram users for its many “selfies” taken along its traverse. These selfies are not all for show though as they help the team track the state of the rover throughout the course of the mission for changes such as wheel wear and dust accumulation. Curiosity’s self-portraits are taken using the rover’s Mars Hand Lens Imager (MAHLI) situated on its robotic arm and are generated by merging a series of high-resolution images into a mosaic. This one taken on sol 1065 at the Buckskin locality shows the main mast of Curiosity with its ChemCam telescope used to determine rock compositions, and the Mastcam cameras. In the foreground you can see that Curiosity has just been drilling, leaving a small grey pile of tailings.

Long drive: This panorama taken with the rover’s Mastcam shows Curiosity’s 18.4km drive over the last 5 years from the Bradbury landing site to its current location on the Vera Rubin Ridge (VRR). VRR was formerly known as Hematite Ridge due to the high concentrations of the iron oxide mineral hematite detected here from orbit. As hematite largely forms in the presence of water, this location was a high-priority target for the Curiosity rover science team to investigate in order to assess how the conditions in Gale Crater changed over its geological history. This key location is the perfect spot for Curiosity to spend its 2000th sol, and for all of us to look back on the many discoveries made so far in the mission.

By John Bridges, Ashwin Vasavada, Susanne Schwenzer, Sanjeev Gupta, Steve Banham, Candice Bedford, Christina Smith, Brittney Cooper & the MSL Team

Curiosity rover: 2,000 days on Mars

Nasa’s Curiosity rover, also known as the Mars Science Laboratory (MSL), is celebrating 2,000 martian days (sols) investigating Gale Crater on the Red Planet. In that time, the robot has made some remarkable observations. Here are just a few of them, chosen by the Curiosity science team.

Looking back: In the history of the space age, some of the most dramatic planetary images ever taken have been of Earth, but photographed looking back from deep space. This image by Mastcam on the Curiosity Rover shows our planet as a faint pinpoint of light in the martian night sky. Every day scientists from across the world drive the Curiosity rover and study the Red Planet about 100 million miles from Earth.

The beginning: The first image that Curiosity took came back just 15 minutes after landing on 5 August 2012. Getting our imagery and other data relies on the timing of Mars Reconnaissance Orbiter (MRO) overpasses, a pattern which determines the structure of the martian working day, or sol. It shows a grainy Front Hazard Camera image – the team normally use these to help avoid obstacles – of our ultimate goal Mount Sharp. When this image came back we knew it was going to be a successful mission.

River pebbles: Once we had started driving (16 sols after landing), we soon came across these pebble beds. The rounded shape of the clasts shows that they formed in an ancient, shallow river, flowing from the surrounding four-billion-year-old highlands into Gale Crater. The inset Mastcam image shows one of the pebbles in close-up. Contrary to our expectations before MSL, the crust being eroded by the rivers was not all dark, primitive basalt but a more evolved composition and mineralogy. Pebbles caught up in this ancient martian river are causing us to rethink our view of how the underlying igneous crust and mantle of Mars formed.

Ancient lake: Before landing and in the early part of the mission, the team wasn’t sure what all of the terrains identified from MRO HiRISE orbital imagery were. They might have been lava flows or lake sediments, without close-up “ground truth” it was impossible to be certain. This image settled the debate and was a seminal stage in Martian exploration. Yellowknife Bay is made of layers of fine grained sand and muds, which were deposited as rivers flowed into an ancient Gale Crater lake. We made our first of 16 drill holes on sol 182 – we do this to get rock in to the spectrometers housed in the body of our rover – here at the John Klein site. The results – including identifying clays, organics and nitrogen-bearing compounds – showed us that this had been a habitable environment for microbial life. The next discovery step – Was There Life? – remains to be determined.

Deep water: The Pahrump Hills section Curiosity encountered around sol 753 was key for developing our understanding of Gale’s past environment. Here the rover observed thinly layered mudstones, which represented mud particles settling out from suspension within the deeper lake. The Gale Lake has been a long-standing, deep body of water.

An unconformity: At Mount Stimson, the rover identified from sol 980 a thick sandstone unit overlying the lake deposits, separated by a geological feature called an unconformity. This unconformity represents a time where erosive processes took over after millions of years when the lake had finally dried up – to form a new land surface. This shows evidence of events happening over “deep time”, similar to those that the pioneering geologist James Hutton described in his field work in the late 18th Century at Siccar Point on the Scottish Coast.

Desert sands: The Namib dunes encountered close up by Curiosity at sol 1192 is a small part of the great Bagnold dune field. Its the first active dunefield explored on the surface of another planet and Curiosity had to pick its way carefully along and through the field as moving sands are an obstacle for rovers. Although the Martian atmosphere is a fraction of the density of that of Earth’s, it is still capable of transporting sediment and is capable of creating such beautiful structures akin to those we see in the deserts of Earth.

Wind sculptures: The Murray Buttes, photographed by Mastcam on sol 1448, formed of the same sandstones observed at Mount Stimson and represent a lithified dune field created by dunes similar to those in the present day Bagnold dune field. These desert-formed sandstones sit above an unconformity, and this suggests that after a long period with a humid climate, the climate became drier and wind became the dominant agent shaping the environment at Gale Crater.

Dried muds: Curiosity is able to perform detailed analyses of the Gale rocks with the ChemCam laser and telescope mounted on its mast. Here on sol 1555 at Schooner Head we came across a set of ancient mudcracks and sulphate veins. On Earth, lakes typically dry up in places around their margins and here on Mars the Gale lake was no different. You can see the red crosses where we fired the laser at the rock, creating a small plasma spark, with the wavelength of light in the spark telling us the composition of the mudstone and veins.

Cloudy skies: This sequence of images was taken with Curiosity’s Navigational Cameras (NavCam) on sol 1971 as we pointed them towards the sky. Occasionally on the cloudiest of Martian days we are able to make out faint clouds in the sky. These images are processed to highlight differences, allowing us to see the clouds move across the sky. This sequence shows previously unseen cloud features with prominent zig-zag patterns visible. The three images, from start to finish, cover approximately 12 minutes on Mars.

Obligatory ‘selfie’: The Curiosity rover has gained a reputation over the years that rivals those of Instagram users for its many “selfies” taken along its traverse. These selfies are not all for show though as they help the team track the state of the rover throughout the course of the mission for changes such as wheel wear and dust accumulation. Curiosity’s self-portraits are taken using the rover’s Mars Hand Lens Imager (MAHLI) situated on its robotic arm and are generated by merging a series of high-resolution images into a mosaic. This one taken on sol 1065 at the Buckskin locality shows the main mast of Curiosity with its ChemCam telescope used to determine rock compositions, and the Mastcam cameras. In the foreground you can see that Curiosity has just been drilling, leaving a small grey pile of tailings.

Long drive: This panorama taken with the rover’s Mastcam shows Curiosity’s 18.4km drive over the last 5 years from the Bradbury landing site to its current location on the Vera Rubin Ridge (VRR). VRR was formerly known as Hematite Ridge due to the high concentrations of the iron oxide mineral hematite detected here from orbit. As hematite largely forms in the presence of water, this location was a high-priority target for the Curiosity rover science team to investigate in order to assess how the conditions in Gale Crater changed over its geological history. This key location is the perfect spot for Curiosity to spend its 2000th sol, and for all of us to look back on the many discoveries made so far in the mission.

By John Bridges, Ashwin Vasavada, Susanne Schwenzer, Sanjeev Gupta, Steve Banham, Candice Bedford, Christina Smith, Brittney Cooper & the MSL Team

Curiosity rover: 2,000 days on Mars

Nasa’s Curiosity rover, also known as the Mars Science Laboratory (MSL), is celebrating 2,000 martian days (sols) investigating Gale Crater on the Red Planet. In that time, the robot has made some remarkable observations. Here are just a few of them, chosen by the Curiosity science team.

Looking back: In the history of the space age, some of the most dramatic planetary images ever taken have been of Earth, but photographed looking back from deep space. This image by Mastcam on the Curiosity Rover shows our planet as a faint pinpoint of light in the martian night sky. Every day scientists from across the world drive the Curiosity rover and study the Red Planet about 100 million miles from Earth.

The beginning: The first image that Curiosity took came back just 15 minutes after landing on 5 August 2012. Getting our imagery and other data relies on the timing of Mars Reconnaissance Orbiter (MRO) overpasses, a pattern which determines the structure of the martian working day, or sol. It shows a grainy Front Hazard Camera image – the team normally use these to help avoid obstacles – of our ultimate goal Mount Sharp. When this image came back we knew it was going to be a successful mission.

River pebbles: Once we had started driving (16 sols after landing), we soon came across these pebble beds. The rounded shape of the clasts shows that they formed in an ancient, shallow river, flowing from the surrounding four-billion-year-old highlands into Gale Crater. The inset Mastcam image shows one of the pebbles in close-up. Contrary to our expectations before MSL, the crust being eroded by the rivers was not all dark, primitive basalt but a more evolved composition and mineralogy. Pebbles caught up in this ancient martian river are causing us to rethink our view of how the underlying igneous crust and mantle of Mars formed.

Ancient lake: Before landing and in the early part of the mission, the team wasn’t sure what all of the terrains identified from MRO HiRISE orbital imagery were. They might have been lava flows or lake sediments, without close-up “ground truth” it was impossible to be certain. This image settled the debate and was a seminal stage in Martian exploration. Yellowknife Bay is made of layers of fine grained sand and muds, which were deposited as rivers flowed into an ancient Gale Crater lake. We made our first of 16 drill holes on sol 182 – we do this to get rock in to the spectrometers housed in the body of our rover – here at the John Klein site. The results – including identifying clays, organics and nitrogen-bearing compounds – showed us that this had been a habitable environment for microbial life. The next discovery step – Was There Life? – remains to be determined.

Deep water: The Pahrump Hills section Curiosity encountered around sol 753 was key for developing our understanding of Gale’s past environment. Here the rover observed thinly layered mudstones, which represented mud particles settling out from suspension within the deeper lake. The Gale Lake has been a long-standing, deep body of water.

An unconformity: At Mount Stimson, the rover identified from sol 980 a thick sandstone unit overlying the lake deposits, separated by a geological feature called an unconformity. This unconformity represents a time where erosive processes took over after millions of years when the lake had finally dried up – to form a new land surface. This shows evidence of events happening over “deep time”, similar to those that the pioneering geologist James Hutton described in his field work in the late 18th Century at Siccar Point on the Scottish Coast.

Desert sands: The Namib dunes encountered close up by Curiosity at sol 1192 is a small part of the great Bagnold dune field. Its the first active dunefield explored on the surface of another planet and Curiosity had to pick its way carefully along and through the field as moving sands are an obstacle for rovers. Although the Martian atmosphere is a fraction of the density of that of Earth’s, it is still capable of transporting sediment and is capable of creating such beautiful structures akin to those we see in the deserts of Earth.

Wind sculptures: The Murray Buttes, photographed by Mastcam on sol 1448, formed of the same sandstones observed at Mount Stimson and represent a lithified dune field created by dunes similar to those in the present day Bagnold dune field. These desert-formed sandstones sit above an unconformity, and this suggests that after a long period with a humid climate, the climate became drier and wind became the dominant agent shaping the environment at Gale Crater.

Dried muds: Curiosity is able to perform detailed analyses of the Gale rocks with the ChemCam laser and telescope mounted on its mast. Here on sol 1555 at Schooner Head we came across a set of ancient mudcracks and sulphate veins. On Earth, lakes typically dry up in places around their margins and here on Mars the Gale lake was no different. You can see the red crosses where we fired the laser at the rock, creating a small plasma spark, with the wavelength of light in the spark telling us the composition of the mudstone and veins.

Cloudy skies: This sequence of images was taken with Curiosity’s Navigational Cameras (NavCam) on sol 1971 as we pointed them towards the sky. Occasionally on the cloudiest of Martian days we are able to make out faint clouds in the sky. These images are processed to highlight differences, allowing us to see the clouds move across the sky. This sequence shows previously unseen cloud features with prominent zig-zag patterns visible. The three images, from start to finish, cover approximately 12 minutes on Mars.

Obligatory ‘selfie’: The Curiosity rover has gained a reputation over the years that rivals those of Instagram users for its many “selfies” taken along its traverse. These selfies are not all for show though as they help the team track the state of the rover throughout the course of the mission for changes such as wheel wear and dust accumulation. Curiosity’s self-portraits are taken using the rover’s Mars Hand Lens Imager (MAHLI) situated on its robotic arm and are generated by merging a series of high-resolution images into a mosaic. This one taken on sol 1065 at the Buckskin locality shows the main mast of Curiosity with its ChemCam telescope used to determine rock compositions, and the Mastcam cameras. In the foreground you can see that Curiosity has just been drilling, leaving a small grey pile of tailings.

Long drive: This panorama taken with the rover’s Mastcam shows Curiosity’s 18.4km drive over the last 5 years from the Bradbury landing site to its current location on the Vera Rubin Ridge (VRR). VRR was formerly known as Hematite Ridge due to the high concentrations of the iron oxide mineral hematite detected here from orbit. As hematite largely forms in the presence of water, this location was a high-priority target for the Curiosity rover science team to investigate in order to assess how the conditions in Gale Crater changed over its geological history. This key location is the perfect spot for Curiosity to spend its 2000th sol, and for all of us to look back on the many discoveries made so far in the mission.

By John Bridges, Ashwin Vasavada, Susanne Schwenzer, Sanjeev Gupta, Steve Banham, Candice Bedford, Christina Smith, Brittney Cooper & the MSL Team