Evidence of water and a warmer, wetter climate abound on Mars, but did life ever put its stamp on the Red Planet? Rocks may hold the secret. Knobby protuberances of rock discovered by the Spirit Rover in 2008 near the rock outcrop Home Plate in Gusev Crater caught the attention of scientists back on Earth. They look like cauliflower or coral, but were these strange Martian rocks sculpted by microbes, wind or some other process?
When analyzed by Spirit’s mini-TES (Mini-Thermal Emission Spectrometer), they proved to be made of nearly pure silica (SiO2), a mineral that forms in hot, volcanic environments. Rainwater and snow seep into cracks in the ground and come in contact with rocks heated by magma from below. Heated to hundreds of degrees, the water becomes buoyant and rises back toward the surface, dissolving silica and other minerals along the way before depositing them around a vent or fumarole. Here on Earth, silica precipitated from water leaves a pale border around many Yellowstone National Park’s hot springs.
Both at Yellowstone, the Taupo Volcanic Zonein New Zealand and in Iceland, heat-loving bacteria are intimately involved in creating curious bulbous and branching shapes in silica formations that strongly resemble the Martian cauliflower rocks. New research presented at the American Geophysical Union meeting last month by planetary geologist Steven Ruff and geology professor Jack Farmer, both of Arizona State University, explores the possibility that microbes might have been involved in fashioning the Martian rocks, too.
A sizzling visit to El Tatio’s geysers
The researchers ventured to the remote geyser fields of El Tatio in the Chilean Atacama Desert to study an environment that may have mimicked Gusev Crater billions of years ago when it bubbled with hydrothermal activity. One of the driest places on Earth, the Atacama’s average elevation is 13,000 feet (4 km), exposing it to considerably more UV light from the sun and extreme temperatures ranging from -13°F to 113°F (-10° to 45°C). Outside of parts of Antarctica, it’s about as close to Mars as you’ll find on Earth.
Ruff and Farmer studied silica deposits around hot springs and geysers in El Tatio and discovered forms they call “micro-digitate silica structures” similar in appearance and composition to those on Mars (Here’s a photo). The infrared spectra of the two were also a good match. They’re still analyzing the samples to determine if heat-loving microbes may have played a role in their formation, but hypothesize that the features are “micro-stromatolites” much like those found at Yellowstone and Taupo.
Stromatolites form when a sticky film of bacteria traps and cements mineral grains to create a thin layer. Other layers form atop that one until a laminar mound or column results. The most ancient stromatolites on Earth may be about 3.5 billion years old. If Ruff finds evidence of biology in the El Tatio formations in the punishing Atacama Desert environment, it puts us one step closer to considering the possibility that ancient bacteria may have been at work on Mars.
Silica forms may originate with biology or from non-biological processes like wind, water and other environmental factors. Short of going there and collecting samples, there’s no way to be certain if the cauliflower rocks are imprinted with the signature of past Martian life. But at least we know of a promising place to look during a future sample return mission to the Red Planet. Indeed, according to Ruff, the Columbia Hills inside Gusev Crater he short list of potential sites for the 2020 Mars rover.
Steve Ruff paper comparing El Tatio with an early hot springs environment in Gusev Crater
Exactly 12 Years ago this week, NASA’s now famous Spirit rover touched down on the Red Planet, starting a spectacular years long campaign of then unimaginable science adventures that ended up revolutionizing our understanding of Mars due to her totally unexpected longevity.
Science is an iterative process, with each discovery building on those made before. This means that as new evidence comes into play, you need to examine the evidence in context of what you know now, and what you knew before. Sometimes the evidence points to new theories. And sometimes, like in this case concerning Mars, it points to older ones.
The Spirit rover spent six years (2004-2010) exploring Gusev Crater, which is just a little south of the Martian equator. Scientists have been back and forth about whether it once was a vast lake of water, but some new research could swing the pendulum towards the water hypothesis.
The water track hinges on magnesium-iron carbonate minerals found in Columbia Hills, a 300-foot (91-meter) feature about two miles (3.2 kilometers) away from Spirit’s landing site. When the minerals were first found in the hills’ Comanche outcrop in 2010, scientists (which included the lead author of the study) attributed this to ancient hot springs activity.
It was a bit of a disappointment for those who had picked Gusev as a landing site from the belief that it was indeed an ancient lake. “From orbit, Gusev looked, with its southern rim breached by a meandering river channel, as if it once held a lake – and water-deposited rocks were the rover mission’s focus,” Arizona State University stated.
Spirit, however, initially found that the crater was lined with volcanic rocks and not the sediments scientists needed to support the lake theory. When it did find evidence of water in the hills, it was linked to hydrothermal activity.
The new analysis suggests that Comanche (and other outcrops in the vicinity) got their liquid from water on the surface that was of a much lower temperature than what you would find in a hot spring –which originates underground.
This is because Comanche and the surrounding area are believed to have started as a buildup of volcanic ash (called a tephra) from eruptions somewhere around Gusev. As the theory goes, waters penetrated Gusev at the south, lingered, and created a “briny solution”. Over time, the brine evaporated and what remained was carbonate minerals residue that coated the rocks.
“The lake didn’t have to be big,” stated Steve Ruff, an associate research professor at Arizona State University who led the research. “The Columbia Hills stand 300 feet high, but they’re in the lowest part of Gusev. So a deep, crater-spanning lake wasn’t needed.”
Getting more information, however, would be one way to add credence to the theory. That’s why the team is also pushing for the forthcoming NASA Mars 2020 rover to land in Gusev Crater, which would be unprecedented among Mars missions as each lander and/or rover has gone to a different spot. Site selection has not been finalized yet.
“Going back to Gusev would give us an opportunity for a second field season there, which any terrestrial geologist would understand,” stated Ruff. “After the first field season with Spirit, we now have a bunch more questions and new hypotheses that can be addressed by going back.”
A Top 10 Decade 1 Discovery by NASA’s Twin Mars Exploration Rovers
Carbonate-Containing Martian Rocks discovered by Spirit Mars Rover
Spirit collected data in late 2005 which confirmed that the Comanche outcrop contains magnesium iron carbonate, a mineral indicating the past environment was wet and non-acidic, possibly favorable to life. This view was captured during Sol 689 on Mars (Dec. 11, 2005). The find at Comanche is the first unambiguous evidence from either Spirit or Opportunity for a past Martian environment that may have been more favorable to life than the wet but acidic conditions indicated by the rovers’ earlier finds. Credit: NASA/JPL-Caltech/Cornell University Story updated[/caption]
January 2014 marks the 10th anniversary since the nail biting and history making safe landings of NASA’s renowned Mars Explorations Rovers – Spirit and Opportunity – on the Red Planet barely three weeks apart during January 2004.
Due to their completely unforeseen longevity, a decade of spectacular and groundbreaking scientific discoveries continuously flowed from the robot sisters that have graced many articles, magazine covers, books, documentaries and refereed scientific papers.
What are the Top 10 Decade 1 discoveries from Spirit and Opportunity?
Find out below what a top Mars rover team scientist told Universe Today!
Ray Arvidson, the rovers Deputy Principal Investigator and professor at Washington University in St. Louis, has kindly shared with me his personal list of the Top 10 discoveries from Spirit and Opportunity for the benefit of readers of Universe Today.
The Top 10 list below are Ray’s personal choices and does not necessarily reflect the consensus of the Mars Explorations Rover (MER) team.
First some background.
The dynamic duo were launched on their interplanetary voyages from Cape Canaveral Florida atop Delta II rockets during the summer of 2003.
The now legendary pair landed on opposite sides of the Red Planet. Spirit landed first on Jan. 3 inside Gusev Crater and twin sister Opportunity landed second on Jan. 24 on the dusty plains of Meridiani Planum.
The goal was to “follow the water” as a potential enabler for past Martian microbes if they ever existed.
Together, the long-lived, golf cart sized robots proved that early Mars was warm and wet, billions of years ago – a key finding in the search for habitats conducive to life beyond Earth.
The solar powered robo duo were expected to last a mere three months – with a ‘warrenty’ of 90 Martian days (Sols).
Spirit endured the utterly extreme Red Planet climate for more than six years until communications ceased in 2010.
Opportunity lives on TODAY and is currently exploring by the summit of Solander Point on the western rim of a vast crater named Endeavour that spans some 22 kilometers (14 miles) in diameter.
“Because of the rovers’ longevity, we essentially got four different landing sites for the price of two,” says the rovers’ Principal Investigator, Steve Squyres of Cornell University, Ithaca, N.Y.
Here are the Top 10 MER discoveries from Ray Arvidson, Deputy Principal Investigator
1. Opportunity: Ancient Acidic Martian Lakes
The Meridiani plains Burns formation as sulfate-rich sandstones with hematitic concretions formed in ancient acidic and oxidizing shallow lakes and reworked into sand dunes and cemented by rising groundwaters.
2. Opportunity: Phyllosilicate Clays at ‘Whitewater Lake’ at Endeavour Crater indicate Ancient Habitable Zone
At the rim of Endeavour crater and the Cape York rim segment the discovery of ferric and aluminous smectite [phyllosilicate] clays in the finely-layered Matijevic formation rocks that pre-exist the Endeavour impact event.
Alteration in moderately acidic and reducing waters, perhaps mildly oxidizing for ferric smectites. These are the oldest rocks examined by Opportunity and the waters are much more habitable than waters that led to Burns formation.
3. Opportunity: Martian Meteorites
Many meteorites were found [throughout the long traverse] that are dispersed across the Meridiani plains landing site
4. Opportunity: Wind-blown sand ripples
Wind-blown sand ripples throughout the Meridiani plains relict from the previous wind regime, probably when Mars spin axis tilt was different than today’s value
5. Spirit: Opaline silica indicates Ancient Hydrothermal system
Discovery of Opaline silica at Home Plate, Gusev Crater. This formed in volcanic fumeroles and/or hydrothermal vents indicating that water was interacting with magma.
6. Spirit: Carbonates at Comanche – see lead image above
The discovery of Fe-Mg [iron-magnesium] carbonates at the Comanche outcrop on Husband Hill, Gusev Crater, again showing that water interacted with magma.
Note: Carbonates form in neutral, non-acid water. This was the first time they were found and investigated examined on the surface Mars during Dec. 2005.
7. Spirit: Ferric sulfates moved by modern water
Ferric sulfates moved down the soil column by modern waters at Troy and Husband Hill in Gusev Crater.
8. Spirit: Modern water alters rocks
Complex coatings on olivine basalts on the Gusev Crater plains showing modern water or frost has altered rock surfaces
9. Both rovers: Martian Dust Devils
The finding [and imaging] of dust devil frequency and dynamics, showing how dust and sand are moved by wind in the very thin Martian atmosphere.
Note: Wind action occasionally cleaning off the solar panels led to their unexpected longevity
See a dust devil imaged in our Solander Point mosaic below
10. Both rovers: Atmospheric Argon measurements
Argon gas was used as a tracer of atmospheric dynamics by both rovers. It was measured by using the APXS (Alpha Particle X-Ray Spectrometer) on the robotic arm to measure the Martian atmosphere and detect argon
Another major discovery by Opportunity was the finding of hydrated mineral veins of calcium sulfate in the bench surrounding Cape York. The vein discovery is another indication of the ancient flow of liquid water in this region on Mars.
Altogether, Spirit snapped over 128,000 raw images, drove 4.8 miles (7.7 kilometers) and ground into 15 rock targets.
Opportunity is currently investigating a new cache of exposed clay mineral outcrops by the summit of Solander Point, a rim segment just south of Cape York and Matejivic Hill.
These new outcrops at ‘Cape Darby’ like those at ‘Esperance’ at Matijevic Hill were detected based on spectral observations by the CRISM spectrometer aboard NASA’s Mars Reconnaissance Orbiter (MRO) circling overhead, Arvidson told me.
Today, Jan. 31, marks Opportunity’s 3563rd Sol or Martian Day roving Mars – for what was expected to be only a 90 Sol mission.
So far she has snapped over 188,200 amazing images on the first overland expedition across the Red Planet.
Her total odometry stands at over 24.07 miles (38.73 kilometers) since touchdown on Jan. 24, 2004 at Meridiani Planum.
What’s Ahead for Opportunity in Decade 2 on Mars ?
Many more ground breaking discoveries surely lie ahead for Opportunity since she is currently exploring ancient terrain at Endeavour crater that’s chock full of minerals indicative of a Martian habitable zone.
She remains healthy and the solar panels are generating enough power to actively continue science investigations throughout her 6th frigid Martian winter!
Therefore – Stay tuned here for Ken’s continuing Opportunity, Curiosity, Chang’e-3, LADEE, MAVEN, Mars rover and MOM news.
A Moment Frozen in Time
On May 19th, 2005, NASA’s Mars Exploration Rover Spirit captured this stunning view as the Sun sank below the rim of Gusev crater on Mars. This Panoramic Camera (Pancam) mosaic was taken around 6:07 in the evening of Sol 489. The terrain in the foreground is the rock outcrop “Jibsheet,” a feature that Spirit has been investigating for several weeks (rover tracks are dimly visible leading up to “Jibsheet”). The floor of Gusev crater is visible in the distance, and the Sun is setting behind the wall of Gusev some 80 km (50 miles) in the distance.
Credit: NASA/JPL-Caltech/Texas A&M/Cornell
See photo gallery below[/caption]
But a decade ago, NASA’s six wheeled Spirit rover was but a promise of great things to come. And her rich Martian scientific heritage we know today was but a dream yet to ensue
Jan. 3 marks the 10th anniversary since her touchdown on Mars on Jan. 3, 2004. Her twin sister Opportunity soft landed 3 weeks later on Jan. 24, 2004.
So here’s a collection of some of Spirit’s greatest hits on the Red Planet for all to enjoy and remember her fabulous exploits.
Read my detailed new overview marking ‘Spirits 10 Years on Mars’ – here – with even more spectacular Red Planet imagery!
Since the golf cart sized Spirit snapped over 128,000 raw images, drove 4.8 miles and ground into 15 rock targets we can’t show everything.
Here’s a retrospective of some of our favorites.
During her more than six year lifetime spanning until March 2010, Spirit discovered compelling evidence that ancient Mars exhibited hydrothermal activity, hot springs and volcanic explosions flowing with water.
“Spirit’s big scientific accomplishments are the silica deposits at Home Plate, the carbonates at Comanche, and all the evidence for hydrothermal systems and explosive volcanism, Rover Principal Investigator Steve Squyres of Cornell University, explained to me in an earlier interview.
“What we’ve learned is that early Mars at Spirit’s site was a hot, violent place, with hot springs, steam vents, and volcanic explosions. It was extraordinarily different from the Mars of today.”
Ten Years Ago, Spirit Rover Lands on Mars
This bird’s-eye view from August 2005 combines a self-portrait of the spacecraft deck and a panoramic mosaic of the Martian surface as viewed by NASA’s Mars Exploration Rover Spirit. The rover’s solar panels are still gleaming in the sunlight, having acquired only a thin veneer of dust two years after the rover landed and commenced exploring the red planet. Spirit captured this 360-degree panorama on the summit of “Husband Hill” inside Mars’ Gusev Crater. During the period from Spirit’s Martian days, or sols, 583 to 586 (Aug. 24 to 27, 2005), the rover’s panoramic camera acquired the hundreds of individual frames for this largest panorama ever photographed by Spirit. Credit: NASA/JPL-Caltech/Cornell
See Spirit’s 1st and last panoramas and more imagery below[/caption]
Today, Jan. 3, marks the 10th anniversary since the safe landing of NASA’s renowned Spirit rover on the plains of Mars on Jan. 3, 2004.
Spirit comprises one half of NASA’s now legendary pair of Mars Exploration Rovers (MER). Opportunity, her twin sister landed, on the opposite side of the Red Planet three weeks later – on Jan. 24, 2004. The goal was to “follow the water” as a potential enabler for past Martian microbes if they ever existed.
Together, the long-lived, golf cart sized robots proved that early Mars was warm and wet, billions of years ago – a key finding in the search for habitats conducive to life beyond Earth.
Exactly a decade ago, the famous robot survived the scorching atmospheric heating of the 6 minute plunge through the thin Martian atmosphere, bounced some two dozen times cocooned inside cushioning airbags, and gradually rolled to a stop inside 100 mile wide Gusev Crater. It was known as the “6 minutes of Terror”.
The three petaled landing pad opened and Spirit was dramatically born in a milestone event that will be forever remembered in the annuls of history because of the groundbreaking scientific discoveries that ensued and the unbelievable longevity of the twins.
Before they were launched atop Delta II rockets in the summer of 2003 from Cape Canaveral, the dynamic, solar powered robo duo were expected to last a mere three months – with a ‘warranty’ of 90 Martian days (Sols).
Either dust accumulation on the life giving solar panels, an engineering issue or the extremely harsh Martian environment was expected to somehow terminate them mercilessly.
In reality, both robots enormously exceeded expectations and accumulated a vast bonus time of exploration and discovery in numerous extended mission phases.
No one foresaw that Martian winds would occasionally clean the solar panels to give them a new lease on life or that the components would miraculously continue functioning.
Spirit endured the utterly extreme Red Planet climate for more than six years until communications ceased in 2010.
Opportunity is still roving Mars today, and doing so in rather good condition!
Altogether, Spirit drove 4.8 miles (7.73 kilometers),that’s about 12 times more than the original goal set for the mission.
She transmitted over 128,000 images.
After landing in the dusty plains, she headed for the nearby Columbia Hills some 2 miles away and ultimately became the first Martian mountaineer, when she scaled Husband Hill and found evidence for the flow of liquid water at the Hillary outcrop.
The rovers were not designed to climb hills. But eventually she scaled 30 degree inclines.
The rover was equipped with a rock grinder named the Rock Abrasion Tool (RAT) built by Honeybee Robotics.
Spirit ground the surfaces off 15 rock targets and scoured 92 targets with a brush to prepare the targets for inspection with spectrometers and a microscopic imager, according to NASA.
Eventually she drove back down the hill and made even greater scientific discoveries in the area known as ‘Home Plate’.
Spirit survived three harsh Martian winters and only succumbed to the Antarctic-like temperatures when she unexpectedly became mired in an unseen sand trap driving beside an ancient volcanic feature named ‘Home Plate’ that prevented the solar arrays from generating life giving power to safeguard critical electronic and computer components.
In 2007, Spirit made one of the key discoveries of the mission at ‘Home Plate’ when her stuck right front wheel churned up a trench of bright Martian soil that exposed a patch of nearly pure silica, which was formed in a watery hot spring or volcanic environment.
Spirit was heading towards another pair of volcanic objects named ‘von Braun’ and ‘Goddard’ and came within just a few hundred feet when she died in the sand trap.
See Spirits last panorama below – created from raw images taken in Feb. 2010 by Marco Di Lorenzo and Ken Kremer.
Here’s how the rovers’ principal investigator, Steve Squyres of Cornell University, Ithaca, N.Y., described some of the key findings in a NASA statement, starting with what Spirit found after driving from the crater floor where it landed into the Columbia hills to the east:
“In the Columbia Hills, we discovered compelling evidence of an ancient Mars that was a hot, wet, violent place, with volcanic explosions, hydrothermal activity, steam vents — nothing like Mars today.
“At Opportunity’s landing site, we found evidence of an early Mars that had acidic groundwater that sometimes reached the surface and evaporated away, leaving salts behind. It was an environment with liquid water, but very different from the environment that Spirit told us about.
“When Opportunity got to the rim of Endeavour Crater, we began a whole new mission. We found gypsum veins and a rich concentration of clay minerals. The clay minerals tell us about water chemistry that was neutral, instead of acidic — more favorable for microbial life, if any ever began on Mars.”
“Because of the rovers’ longevity, we essentially got four different landing sites for the price of two.”
January 2012 marks the 8th anniversary since of the daring landing’s of “Spirit” and “Opportunity” – NASA’s now legendary twin Mars Exploration Rovers (MER), on opposite sides of the Red Planet in January 2004. They proved that early Mars was warm and wet – a key finding in the search for habitats conducive to life beyond Earth.
I asked the leaders of the MER team to share some thoughts celebrating this mind-boggling milestone of “8 Years on Mars” and the legacy of the rovers for the readers of Universe Today. This story focuses on Spirit, first of the trailblazing twin robots, which touched down inside Gusev Crater on Jan. 3, 2004. Opportunity set down three weeks later on the smooth hematite plains of Meridiani Planum.
“Every Sol is a gift. We push the rovers as hard as we can,” Prof. Steve Squyres informed Universe Today for this article commemorating Spirit’s landing. Squyres, of Cornell University, is the Scientific Principal Investigator for the MER mission.
“I seriously thought both Spirit and Opportunity would be finished by the summer of 2004,” Ray Arvidson told Universe Today. Arvidson, of Washington University in St. Louis, is the deputy principal investigator for the MER rovers.
Spirit endured for more than six years and Opportunity is still roving Mars today !
The dynamic robo duo were expected to last a mere three months, or 90 Martian days (sols). In reality, both robots enormously exceeded expectations and accumulated a vast bonus time of exploration and discovery in numerous extended mission phases.
Spirit survived three harsh Martian winters and only succumbed to the Antarctic-like temperatures when she unexpectedly became mired in an unseen sand trap driving beside an ancient volcanic feature named ‘Home Plate’ that prevented the solar arrays from generating life giving power to safeguard critical electronic and computor components.
Spirit was heading towards another pair of volcanic objects named von Braun and Goddard and came within just a few hundred feet when she died.
“I never thought that we would still be planning sequences for Opportunity today and that we only lost Spirit because of her limited mobility and bad luck of breaking through crusty soil to get bogged down in loose sands,” said Arvidson
By the time of her last dispatch from Mars in March 2010, Spirit had triumphantly traversed the red planets terrain for more than six years of elapsed mission time – some 25 times beyond the three month “warranty” proclaimed by NASA as the mission began back in January 2004.
“I am feeling pretty good as the MER rover anniversaries approach in that Spirit had an excellent run, helping us understand without a doubt that early Mars had magmatic and volcanic activity that was “wet”, Arvidson explained.
“Magmas interacted with ground water to produce explosive eruptions – at Home Plate, Goddard, von Braun – with volcanic constructs replete with steam vents and perhaps hydrothermal pools.”
Altogether, the six wheeled Spirit drove over 4.8 miles (7.7 kilometers) and the cameras snapped over 128,000 images. NASA hoped the rovers would drive about a quarter mile during the planned 90 Sol mission.
“Milestones like 8 years on Mars always make me look forward rather than looking back,” Squyres told me.
Spirit became the first robotic emissary from humanity to climb a mountain beyond Earth, namely Husband Hill, a task for which she was not designed.
“No one expected the rovers to last so long,” said Rob Manning to Universe Today. Manning, of NASA’s Jet Propulsion laboratory, Pasadena, CA. was the Mars Rover Spacecraft System Engineering team lead for Entry, Descent and Landing (EDL)
“Spirit surmounted many obstacles, including summiting a formidable hill her designers never intended her to attempt.”
“Spirit, her designers, her builders, her testers, her handlers and I have a lot to be thankful for,” Manning told me.
After departing the Gusev crater landing pad, Spirit traversed over 2 miles to reach Husband Hill. In order to scale the hill, the team had to create a driving plan from scratch with no playbook because no one ever figured that such a mouthwatering opportunity to be offered.
It took over a year to ascend to the hill’s summit. But the team was richly rewarded with a science bonanza of evidence for flowing liquid water on ancient Mars.
Spirit then descended down the other side of the hill to reach the feature dubbed Home Plate where she now rests and where she found extensive evidence of deposits of nearly pure silica, explosive volcanism and hot springs all indicative of water on Mars billions of years ago.
“Spirit’s big scientific accomplishments are the silica deposits at Home Plate, the carbonates at Comanche, and all the evidence for hydrothermal systems and explosive volcanism, Squyres explained. “ What we’ve learned is that early Mars at Spirit’s site was a hot, violent place, with hot springs, steam vents, and volcanic explosions. It was extraordinarily different from the Mars of today.”
“We’ve still got a lot of exploring to do [with Opportunity], but we’re doing it with a vehicle that was designed for a 90-sol mission,” Squyres concluded. “That means that ever sol is a gift at this point, and we have to push the rover and ourselves as hard as we can.”
NASA concluded the last attempt to communicate with Spirit in a transmission on May 25, 2011.
Meanwhile, the Curiosity Mars Science Lab rover, NASA’s next Red Planet explorer, continues her interplanetary journey on course for a 6 August 2012 landing at Gale Crater.
Scientists leading NASA’s Mars rover team have selected “Spirit Point” as the name for the spot where the “Opportunity” Mars rover will arrive at her next destination – Endeavour Crater. The site was named in honor of the death of the “Spirit” Mars Exploration Rover, which NASA recently declared has ceased all communications with Earth.
Spirit’s passing comes after more than six highly productive years roving the surface of the red planet as humankind’s surrogate. NASA concluded the last attempt to communicate with Spirit in a transmission on May 25, 2011.
“First landfall at Endeavour will be at the southern end of Cape York [at Spirit Point],” Steve Squyres told me. Squyres of Cornell University, Ithaca, N.Y., is principal investigator for the rovers. Read tributes from the Spirit rover science team below.
In memory of Spirit, the last panorama she snapped on Sol 2175 in February 2010 was featured on Astronomy Picture of the Day (APOD) on May 30, 2011 and is the lead image here. The photo mosaic was created by Marco Di Lorenzo and Ken Kremer and shows some of the last scenes that Spirit ever photographed.
Endeavour’s massive rim consists of a series of ridges. Cape York is a 400 foot wide (120 meters) rim fragment at the western edge of Endeavour. Opportunity should reach “Spirit Point” before the end of this year, 2011.
“Spirit Point” was chosen as the site at Endeavour to commemorate the scientific achievements of Opportunity’s twin sister “Spirit”. Endeavour Crater was determined to be Opportunity’s long term destination nearly three ago after she departed the environs of Victoria crater.
“The Initial exploration plan will be decided when we get closer. The [science] priorities will depend on what we find,” Squyres added.
Since August 2008, the blistering pace of Opportunity’s long overland trek of about 11 miles (18 kilometers) has brought the golf cart sized robot to within about 2 miles (3 kilometers) of the rim of the humongous Endeavour crater – some 14 miles (22 kilometers) in diameter. Endeavour is more than 20 times wider than Victoria crater and by far the largest feature the Opportunity will ever explore – see route maps below.
“Spirit achieved far more than we ever could have hoped when we designed her,” according to Squyres in a NASA statement. “This name will be a reminder that we need to keep pushing as hard as we can to make new discoveries with Opportunity. The exploration of Spirit Point is the next major goal for us to strive for.”
The imaging team of Marco Di Lorenzo and Ken Kremer created a series of Spirit photomosaics from publically available images to illustrate the location and hazardous nature of Spirits final resting place – which fortuitously turned out to be a scientific goldmine revealing new insights into the flow of liquid water on Mars billions of years ago.
The western rim of Endeavour possesses geological deposits far older than any Opportunity has investigated before and which may feature environmental conditions that were more conducive to the potential formation of ancient Martian life forms.
Spirits last transmissions to Earth took place in March 2010, before she entered hibernation mode due to ebbing solar power and succumbed to the likely damaging effects of her 4th Martian winter.
Spirit was closing in on her next science target, a mysterious volcanic feature named Von Braun, when she became mired in a sand trap named “Troy” on the outskirts of the eroded volcano named “Home Plate, just about 500 feet away. See our mosaics.
Unable to escape and absent of sufficient power to run critical survival heaters, Spirit experienced temperatures colder than ever before that probably crippled fragile electronics components and connections and prevented further communications – although no one knows for sure.
NASA’s twin rovers Spirit and Opportunity have been exploring the Martian terrain on opposite sides of the red planet since the dynamic duo successfully landed over 7 years ago in January 2004.
Both robots were expected to last just three months but have accumulated a vast bonus time of exploration and discovery in numerous extended mission phases.
*** Several top members of the rover science team kindly provided me some comments (below) to sum up Spirits achievements and legacy and what’s ahead for Opportunity at Endeavour.
Ray Arvidson of Washington University, St Louis, Deputy Principal Investigator for the rovers:
“Spirit’s last communication with Earth was in March 2010 as the southern hemisphere winter season began to set in, the sun was low on the horizon, and the rover presumably stopped communicating to use all available solar power to charge the batteries.
Von Braun was one of the two destinations Spirit was traveling to when the rover became embedded in soft sands in the valley to the west of Home Plate.
Von Braun is a conically-shaped hill to the south of Home Plate, Inner Basin, Columbia Hills. Goddard is an oval-shaped shallow depression to the west of von Braun and was the second area to be visited by Spirit. Both von Braun and Goddard are suspected to be volcanic features.
During Spirit’s six year and two month mission the vehicle acquired remote sensing and in-situ observations that conclusively demonstrated that the ancient Columbia Hills in Gusev Crater expose materials that have been altered in water-related environments, including ground water corrosion and generation of sulfate and opaline minerals in volcanic steam vents and perhaps hydrothermal pools.
Together with its sister rover, Opportunity, the Mars Exploration Rover Mission, was designed to “follow the water” and return data that would allow us to test the hypothesis that water was at and near the surface during previous epochs.
Opportunity is still exploring the evidence in Meridiani for ancient shallow lakes and is on the way to outcrops on the rim of Endeavour crater, a ~20 km wide crater that exposes the old Noachian crust that shows evidence from orbital data for hydrated clay minerals.
These two rovers have performed far beyond expectations, unveiled the early, wet history of Mars, and have made an enormous scientific return on investment.”
Steve Squyres of Cornell University, Ithaca, N.Y., Principal Investigator for the rovers:
“Our best hope for hearing from Spirit was last fall. When that didn’t happen, we began a long, careful process of trying every possible approach to re-establishing contact. But it slowly became clear that it was unlikely, and I personally got used to the idea that Spirit’s mission was probably over several months ago.
Once that right front wheel failed, Spirit’s days were numbered in that kind of terrain. It wouldn’t have made any difference if we had tried to move Spirit sooner. We were very lucky to have survived as long as we did.
One of the lessons learned is to try to keep the wheels from failing.
It’s very sad to lose Spirit. But two things have softened the blow. First we’ve had a long time to get used to the idea. Second, even though Spirit is dead, she died an honorable death. If we’d lost her early in the mission, before she accomplished so much, it would have been much harder. But she accomplished so much more than any of us expected, the sadness is very much tempered with satisfaction and pride.
The big scientific accomplishments are the silica deposits at Home Plate, the carbonates at Comanche, and all the evidence for hydrothermal systems and explosive volcanism. What we’ve learned is that early Mars at Spirit’s site was a hot, violent place, with hot springs, steam vents, and volcanic explosions. It was extraordinarily different from the Mars of today.
Opportunity is heading at high speed for the rim of Endeavour Crater. First landfall will be at the southern end of Cape York. She should be there in not too many more months.
It hasn’t yet been decided where Opportunity will attempt to climb up Endeavour… we’ll see when we get there.
The phyllosilicates are a high priority, but the top priority depends on what we find.
I hope Spirits legacy will be the inspiration that people, especially kids, will take away from Spirit’s mission. I have had long, thoughtful conversations about Spirit with kids who have had a rover on Mars as long as they can remember. And my fondest hope for Spirit is that somewhere there are kids who will look at what we did with her, and say to themselves “well, that’s pretty cool… but I bet when I grow up I can do better. That’s what we need for the future of space exploration.
Spirit existed, and did what she did, because of the extraordinary team of engineers and scientists who worked so hard to make it possible. It’s a team that I’m incredibly proud to have been a small part of. Working with them has been quite literally the adventure of a lifetime.”
Jim Bell of Arizona State University, lead scientist for the rovers Pancam stereo panoramic camera:
“It is with a bittersweet sense of both sadness and pride that NASA announced the official end of the mission for the Mars Exploration Rover Spirit.
The Spirit team has seen the end coming since communications were lost with the rover in March 2010. Mission engineers made heroic efforts to reestablish contact. In the end Spirit was conquered by the extremely cold Martian winter and its two broken wheels, which prevented its dusty solar panels from pointing toward the Sun.
But what a mission! Designed to last 90 days, Spirit kept going for more than six years, with the team driving the rover almost 5 miles (8 km) across rocky volcanic plains, climbing rugged ancient hills, and scurrying past giant sand-dune fields. It eventually spent most of the mission near the region known as Home Plate, which is full of layered, hydrated minerals.
Data from the rover enabled dozens of scientific discoveries, but three stand out to me as most important:
Hydrated sulfate and high-silica soils in the Columbia Hills and around Home Plate.
These minerals, and the environment in which they occur (Home Plate is a circular-shaped, finely layered plateau that may be the eroded remains of a volcanic cone or other hydrothermal deposit), tell us that at some point in the past history of Gusev there was liquid water and there were heat sources — two key ingredients needed to consider the area habitable for life as we know it.
Carbonate minerals in some of the rocks within the Columbia Hills.
Carbonates were expected on Mars, if indeed the climate was warmer and wetter in the past. However, their detection has been elusive so far. Indeed, the Spirit team had to work hard to uncover the signature of carbonates years after the rover made the measurements. As the analysis continues the results for Mars in general could be profound.
An incredible diversity of rock types, from all over Mars, that Spirit was able to sample in Gusev crater.
Some of the rocks appear to be from local volcanic lava flows or ash deposits. But others have likely been flung in to the area over time by distant impacts or volcanoes, and a few even appear to be meteorites, flung in from outer space. Spirit’s instruments provided the team with the ability to recognize this amazing diversity, and thus to learn much more about Mars in general, not just Gusev in particular.
Spirit also helped us test an experiment: If we put all the rover’s images out on the Web for everyone in the world to see, in near real-time, would people follow along? They did!
I wonder if, maybe 10 or 15 years from now, I’ll meet some young colleagues who were turned on to space exploration by being able to check out the latest Spirit images from Mars from their classroom, or living room, every day when they were a kid. That would be extremely satisfying — and a great testament to the power of openly sharing data from space exploration missions like Spirit’s.
Meanwhile, Opportunity continues to rove on to city-size Endeavour crater, where orbital measurements have identified, for the first time in either rover’s mission, the signatures of clay minerals in the crater’s rim. Clays are also formed in water, but in less acidic, perhaps more life-friendly water than the sulfates that Opportunity has been mapping thus far.”
Rob Manning, Jet Propulsion laboratory, Pasadena, CA., Mars Rover Spacecraft System Engineering team lead
“Although Opportunity has proven her endurance, Spirit was the one we struggled with the hardest to get what she earned. Suffering from late repair and modification, a blown fuse in her power system and with possibly damaged circuits, she was very late getting out the door and onto the pad in Florida.
Unlike Opportunity, whose Hematite-laden Meridiani destination had been established long before launch, Spirit was launched with a great deal of uncertainty on where she would find herself on Mars. Would it be the flat and safe plains of Elysium? Would the intriguing but rough ancient Gusev crater with what appears to have been an ancient river flowing into a giant but now dry lake?
If Opportunity failed to get on her way to Mars, would her destination become Meridiani? Would Spirit have also been as lucky to find herself bouncing into a tiny rock-outcropped crater as Opportunity had?
Only after the successful launch of Opportunity followed by further successful rocket and airbag tests to confirm that the landing system design would work in the rougher terrain inside Gusev crater allowed us to seal her fate and her permanent home.
She would go Gusev and test the Gusev lake hypothesis. Sadly the surface of Gusev where she came to rest revealed a meteor impact-tilled lake of ancient lava. Any signs of ancient water lake beds and other fantastic discoveries would have to wait until she surmounted many more obstacles including summiting a formidable hill her designers never intended her to attempt.
Spirit, her designers, her builders, her testers, her handlers and I have a lot to be thankful for.
That NASA, the congress and the public were willing to trust us with this daunting feat is perhaps a statement about the persistent spirit of discovery that remains in all of us.