Water, Water Everywhere… Lunar Samples Show More Water Than Previously Thought

Orange lunar soil collected by Apollo 17 contains more water than once thought. Credit: NASA.

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A team of NASA-funded researchers led by Carnegie Institution’s Erik Hauri has recently announced the discovery of more water on the Moon, in the form of ancient magma that has been locked up in tiny crystals contained within soil samples collected by Apollo 17 astronauts. The amounts found indicate there may be 100 times more water within lunar magma than previously thought… truly a “watershed” discovery!

Orange-colored lunar soil sampled during Apollo 17 EVA missions was tested using a new ion microprobe instrument which measured the water contained within magma trapped inside lunar crystals, called “melt inclusions”. The inclusions are the result of volcanic eruptions on the Moon that occurred over 3.7 billion years ago.

Because these bits of magma are encased in crystals they were not subject to loss of water or “other volatiles” during the explosive eruption process.

“In contrast to most volcanic deposits, the melt inclusions are encased in crystals that prevent the escape of water and other volatiles during eruption. These samples provide the best window we have to the amount of water in the interior of the Moon.”

–  James Van Orman of Case Western Reserve University, team member

While it was previously found that water is contained within lunar magma during a 2008 study led by Alberto Saal of Brown University in Providence, Rhode Island, this new announcement is based upon the work of Brown undergraduate student Thomas Weinreich, who located the melt inclusions. By measuring the water content of the inclusions, the team could then infer the amount of water present in the Moon’s interior.

The results also make correlations to the proposed origins of the Moon. Currently-accepted models say the Moon was created following a collision between the newly-formed Earth and a Mars-sized protoplanet 4.5 billion years ago. Material from the Earth’s outer layers was blasted out into space, forming a ring of molten material that encircled the Earth and eventually coalesced, cooled and became the Moon. This would also mean that the Moon should have similarities in composition to material that would have been found in the outer layers of the Earth at that time.

“The bottom line is that in 2008, we said the primitive water content in the lunar magmas should be similar to lavas coming from the Earth’s depleted upper mantle. Now, we have proven that is indeed the case.”

– Alberto Saal, Brown University, RI

The findings also suggest that the Moon’s water may not just be the result of comet or meteor impacts – as was suggested after the discovery of water ice in polar craters by the LCROSS mission in 2009 – but may also have come from within the Moon itself via ancient lunar eruptions.

The success of this study makes a strong case for finding and returning similar samples of ejected volcanic material from other worlds in our solar system.

“We can conceive of no sample type that would be more important to return to Earth than these volcanic glass samples ejected by explosive volcanism, which have been mapped not only on the Moon but throughout the inner solar system.”

– Erik Hauri, lead author, Carnegie’s Department of Terrestrial Magnetism

The results were published in the May 26 issue of Science Express.

Read the full NASA news release here.

Black Holes Spin Outta’ Control

An artist’s impression of the jets emerging from a supermassive black hole at the center of the galaxy PKS 0521-36. Credit: Dana Berry / STScI

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“Down in a hole and they’ve put all the stones in their place. I’ve eaten the sun so my tongue has been burned of the taste…” For the first time the evolution of the spin of the supermassive black holes has finally been examined. New research hints that supermassive black holes enlarged by swallowing matter will barely show spin, while those that merge with other black holes take on a rapid spin rate. Outta’ control? Let’s check the evidence.

Dr Alejo Martinez-Sansigre of the University of Portsmouth and Prof. Steve Rawlings of the University of Oxford made the new discovery by using radio, optical and X-ray data. Their findings were that giant black holes are – on the average – spinning faster than ever. With masses anywhere between a million and billion times that of the Sun, the net they weave isn’t visible to the eye – but the accretion disk is. The material becomes superheated, emitting X-rays detectable by space-telescopes. And, like great rock music, they emit some powerful radio waves able to be picked up by terrestrially based equipment.

But that’s not all these powerful babies kick up. We also know that twin jets are often associated with black holes and their accretion disks. The evolution of the jets can be caused by many factors, but now we’re beginning to associate spin rate with their formation as well. Through sampling radio observations Dr Martinez-Sansigre and Professor Rawlings were able to deduce the power of the jets and how they acquire material. From there, they could hypothesize how quickly these objects are spinning. These same observations provided data on black hole evolution. According to their research, the early Universe black holes had a much slower spin rate compared to the fraction of those found rapidly spinning in the present.

“The spin of black holes can tell you a lot about how they formed. Our results suggest that in recent times a large fraction of the most massive black holes have somehow spun up.” said Dr Martinez-Sansigre. “A likely explanation is that they have merged with other black holes of similar mass, which is a truly spectacular event, and the end product of this merger is a faster spinning black hole.”

Professor Rawlings adds: “Later this decade we hope to test our idea that these supermassive black holes have been set spinning relatively recently. Black hole mergers cause predictable distortions in space and time – so-called gravitational waves. With so many collisions, we expect there to be a cosmic background of gravitational waves, something that will change the timing of the pulses of radio waves that we detect from the remnants of massive stars known as pulsars.

Radio waves? You bet. “Down in a hole. Outta’ control…”

Rapid Formation May Have Stunted Mars’ Growth

Credit: Christopher Leather, University of Chicago

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Somewhere between two and four million years after our solar system formed, a rocky little runt went through a rapid growth spurt. In its embryonic stage, it was much like Earth. But it didn’t end up being terrestrial. Earth ended up being twice its size through collecting other rocky bodies as they passed by. But not Mars… Oh, no. Not Mars.

“Earth was made of embryos like Mars, but Mars is a stranded planetary embryo that never collided with other embryos to form an Earthlike planet.” said Nicolas Dauphas at the University of Chicago. “Mars probably is not a terrestrial planet like Earth, which grew to its full size over 50 to 100 million years via collisions with other small bodies in the solar system.”

The latest study of Mars just released in Nature puts forth the theory that the red planet’s rapid formation helps explain why it is so small. The idea isn’t new, but based on a proposal done 20 years ago and heightened by planetary growth simulations. The only thing missing was evidence… evidence that’s hard to come by since we can’t examine firsthand the formation history of Mars because of the unknown composition of its mantle – the rock layer beneath the planetary crust.

So what has changed that gives us a new view of how Mars came to be the runt of the solar system litter? Try meteorites. By analyzing Martian meteorites, the team was able to pick out clues about the mantle composition of Mars, but their compositions also have changed during their journey through space. This debris left over from the genesis time is nothing more than a common chondrite – a Rosetta stone for deducing planetary chemical composition. Dauphas and Pourmand analyzed the abundances of these elements in more than 30 chondrites, and compared those to the compositions of another 20 martian meteorites.

“Once you solve the composition of chondrites you can address many other questions,” Dauphas said.

And there are many, many questions left to be answered. Cosmochemists have intensively studied chondrites, but still poorly understand the abundances of two categories of elements they contain, including uranium, thorium, lutetium and hafnium. Hafnium and thorium both are refractory or non-volatile elements, meaning that their compositions remain relatively constant in meteorites. They also are lithophile elements, those that would have stayed in the mantle when the core of Mars formed. If scientists could measure the hafnium-thorium ratio in the martian mantle, they would have the ratio for the whole planet, which they need to reconstruct its formation history. When the team of Dauphas and Pourmand had determined this ratio, they were able to calculate how long it took Mars to develop into a planet. Then, by applying a simulation program, they were able to deduce that Mars… Oh, yes. Mars. Reached its full growth only two million years after the solar system.

“New application of radiogenic isotopes to both chondrite and martial meteorites provides data on the age and mode of formation of Mars,” said Enriqueta Barrera, program director in NSF’s Division of Earth Sciences. “That is consistent with models that explain Mars’ small mass in comparison to that of Earth.”

And still there are questions… But fast formation seems to be the answer. It might explain the puzzling similarities in the xenon content of its atmosphere and that of Earth’s. “Maybe it’s just a coincidence, but maybe the solution is that part of the atmosphere of Earth was inherited from an earlier generation of embryos that had their own atmospheres, maybe a Marslike atmosphere,” Dauphas said.

Mars? Oh, no. Not Mars.

Source: University of Chicago, AAS

Best Images from STS-134, Endeavour’s Final Mission, Part 1

Astronaut Drew Feustel reenters the space station after completing an 8-hour, 7-minute spacewalk at on Sunday, May 22, 2011. He and fellow spacewalker Mike Fincke conducted the second of the four EVAs during the STS-134 mission. Credit: NASA

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It’s bittersweet: a very successful STS-134 shuttle mission going on right now, but it’s the last one ever for space shuttle Endeavour, and the second to the last shuttle mission ever. The best way to savor the mission is to enjoy some of the wonderful images being beamed down from space.

This striking image of Endeavour shooting up through the cloud deck was taken from a shuttle training aircraft on May 16, just seconds after Endeavour launched. Credit: NASA
NASA astronaut Michael Fincke, STS-134 mission specialist, appears delighted that, because of the weightlessness of space, he can renew doing chores which he can't do on Earth, like lifting heavy bags and floating freely at the same time. Credit: NASA
Endeavour approaches the International Space Station. Visible is the Alpha Magnetic Spectrometer in the payload bay. Credit: NASA
This is the last time this will be seen in space: Endeavour's wing is photographed from the ISS during the shuttle's approach. Credit: NASA
This view of the nose, the forward underside and crew cabin of Endeavour was taken by a crew member on board the ISS during a a photo survey of the approaching STS-134 crew, looking for potential problems in the thermal protection system. Credit: NASA
A careful look at this scene in Earth orbit reveals the International Space Station (ISS) at frame center, as the ISS and Endeavour (partially seen in foreground) prepare to dock. Photo credit: NASA
The ISS hovers in the aft flight deck window of space shuttle Endeavour during rendezvous and docking operations. Photo credit: NASA
Commander Mark Kelly and Greg Johnson looks at the various mission insignias placed in the Unity node of the International Space Station before placing the STS-134 insignia among them. Credit: NASA
Can you find the astronauts in this image? Drew Feustel (top left) and Greg Chamitoff (center left), work during the first EVA of the STS-134 mission. Credit: NASA
NASA astronauts Michael Fincke (left), STS-134 mission specialist; and Ron Garan, Expedition 28 flight engineer pose with their headlights, worn so they can see while working behind a rack on the International Space Station. Credit: NASA
One of the solar array wings on the ISS is backlit by a thin line of Earth's atmosphere. Credit: NASA
Astronauts Andrew Feustel (right) and Michael Fincke work during the STS-134 mission's third spacewalk. Credit: NASA
Shuttle Endeavour docked to the ISS, backdropped by a thinly lit part of Earth's atmosphere and the blackness of orbital nighttime in space. Credit: NASA
ESA astronaut Roberto Vittori floats through the Destiny laboratory of the International Space Station during the STS-134 mission. Credit: NASA
How the mission started: Endeavour's final launch on May 16, 2011. Credit: Alan Walters (awaltersphoto.com) for Universe Today.

Click on each image to get access to higher resolution images, or see more images at NASA’s Human Spaceflight webpage gallery, and NASA’s Image of the Day gallery.

Through The Eyes of WISE… Galaxies Seen In A New Light

Galaxy Shapes
Image credit: NASA/JPL-Caltech/UCLA

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NASA’s Wide-field Infrared Survey Explorer (WISE) just released a new series of galactic images – allowing us just a hint at the amazing, and colorful, things to come. Release data products include an Atlas of 10,464 calibrated, co-added Image Sets and a Source Catalog containing positional and photometric information for over 257 million objects detected on the WISE images. Out of all this data, the mission plans to release a thousand images and possibly more…

“Galaxies come in all sorts of delicious flavors,” said Tom Jarrett, a WISE team member at the Infrared Processing and Analysis Center, California Institute of Technology, in Pasadena, who studies our Milky Way’s neighboring galaxies. “Our first sample shows what WISE is capable of. We can produce spectacular high-resolution images of the largest galaxies.”

Images taken in infrared light have been transformed into colors we can understand and relate to. Short wavelengths appear as blue and the longest are red. By token, aging stars appear blue, while clusters of newly formed stars take on yellow or reddish hues. This newly released image gives us a great sampler of all galaxy types – from elegant to disturbed. Because they are “close to home”, these particular galactic images taken through the eyes of WISE will allow us further insight as to their formation and evolution.

“We can learn about a galaxy’s stars — where are they forming and how fast?” said Jarrett. “There’s so much diversity in galaxies to explore.”

WISE, which launched into space in Dec. 2009, has been a busy project. Scanning the whole sky one-and-a-half times in infrared light, the mission has captured images as close as asteroids in our own solar system and distant galaxies billions of light-years away. The first data set, which ironically doesn’t include all of the galaxies in the new collage, was released to the public in April of this year. The complete WISE catalog will follow a year later, in the spring of 2012.

Says NASA; “The most distant objects that will stand out like ripe cherries in WISE’s view are tremendously energetic galaxies. Called ultraluminous infrared galaxies, or ULIRGs, these objects shine with the light of up to a trillion suns. They crowd the distant universe, but appear virtually absent in visible-light surveys. WISE should find millions of ultra-luminous infrared galaxies, and the most luminous of these could be the most luminous galaxy in the Universe.”

Source: Berkeley U.

From 2MASS To You… The Most Complete 3-D Map of Local Universe

Credit: T.H. Jarrett (IPAC/SSC)

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Isn’t this era of astronomy incredible? There are times when I thumb through my old astronomy books with their outdated information and simply marvel over today’s capabilities. Who would have believed just 50 years ago that we’d be peering into the far reaches of our Universe – let alone mapping them? Thanks to an endeavor that took more than 10 years to complete, the 2MASS Redshift Survey (2MRS) has provided us with 3-D map which cuts through the dust and pushes the envelope of the Galactic Plane out to 380 million light-years – encompassing more than 500 million stars and resolving more than 1.5 million galaxies.

With our current understanding of expansion, we accept a distant galaxy’s light is stretched into longer wavelengths – or redshifted. By default, this means the further a galaxy is away, the greater the redshift will be. This then becomes a critical factor in producing a three-dimensional point in mapping. To cut through the layers of obscuring dust, the original Two-Micron All-SkySurvey (2MASS) visualized the entire visible sky in three near-infrared wavelength bands. While it gave us an incredible look at what’s out there, it lacked a critical factor… distance. Fortunately, some of the galaxies logged by 2MASS had known redshifts, and thus began the intense “homework” of measurements in the late 1990s using mainly two telescopes: one at the Fred Lawrence Whipple Observatory on Mt. Hopkins, AZ, and one at the Cerro Tololo Inter-American Observatory in Chile.

“Our understanding of the origin and evolution of the Universe has been fundamentally transformed with seminal redshift, distant supernovae and cosmic microwave background surveys. The focus has shifted to the distribution and nature of dark matter and dark energy that drive the dynamics of the expanding cosmos.” says team member, Thomas Jarrett. “The study of the local Universe, including its peculiar motions and its clustering on scales exceeding 100 Mpc, is an essential ingredient in the connection between the origin of structure in the early Universe and the subsequent formation of galaxies and their evolution to the state we observe today. Key issues include the location and velocity distribution of galaxies, leading to the mass-to-light relationship between what is observed and what is influencing the mass density field.”

What makes this work so impressive? The 2MRS has logged what’s been previously hidden behind our Milky Way – allowing us to comprehend the impact they have on our motion. From the time astronomers first measured our movement relative to the rest of the Universe and realized it couldn’t be explained by the gravitational attraction from any visible matter, it became a huge jigsaw puzzle just waiting to have the pieces match up. Now massive local structures, like the Hydra-Centaurus region (the “Great Attractor”) which were previously hidden almost behind the Milky Way are shown in great detail by 2MRS. The Galactic “zone of avoidance” (ZoA) is still, however, a formidable barrier due to the sheer number of stars that produce a foreground (confusion) “noise”. Near the center of the Milky Way the confusion noise is extreme, blocking nearly 100% of the background light; whereas far from the Galactic center the confusion noise is minimal and the veil of the Milky Way is lifted at near-infrared wavelengths

“The 2MASS catalog has proven to be quite versatile to the astronomical community: supporting observation and future mission planning, seeding studies of star formation and morphology in nearby galaxies, penetrating the zone of avoidance, providing the base catalog of redshift and Tully-Fisher HI surveys, and so on. But perhaps its most important function is to provide the “big picture” context for analysis and interpretation of data concerning galaxy clusters, large scale structure and the density of matter in the Universe.” says Jarrett. “And so the primary motivation of this work, with the construction of qualitative “road” maps to the local Universe, is to provide a broad framework for studying the physical connection between the local Universe (Milky Way, Local Group, Local Supercluster, “Great Wall”, etc) and the distant Universe where galaxies and the cosmic web first formed. The best is yet to come.”

UK and European Space Agencies Give a Go For Skylon Spaceplane

An artist's conception of Reaction Engines' Skylon spacecraft. Credit: Reaction Engines

After 30 years of development, the UK and European space agencies have given a go for the Skylon Spaceplane.

The Skylon, which is being developed at the Oxfordshire-based Reaction Engines in the UK, is an unpiloted and reusable spacecraft that can launch into Low Earth Orbit after taking off from a conventional runway.

Looking like something out of Star Wars, Skylon is a self contained, single stage, all in one reusable space vehicle. There are no expensive booster rockets, external fuel tanks or huge launch facilities needed.

The vehicle’s hybrid SABRE engines use liquid hydrogen combined with oxygen from the atmosphere at altitudes up to 26km and speeds of up to Mach 5, before switching over to on-board fuel for the final rocket powered stage of ascent into low Earth orbit.

The Skylon is intended to cut the costs involved with commercial activity in space, delivering payloads of up to 15 tons including satellites, equipment and even people into orbit at costs much lower than those that use expensive conventional rockets.

Once the spacecraft has completed its mission, it will re-enter Earth’s atmosphere and return to base, landing like an airplane on the same runway, making it a totally re-usable spaceplane, with a fast mission turn around.

Skylon has received approval from a European Space Authority panel tasked with evaluating the design. “No impediments or critical items have been identified for either the Skylon vehicle or the SABRE engine that are a block to further development,” the panel’s report concludes.

“The consensus for the way forward is to proceed with the innovative development of the engine which in turn will enable the overall vehicle development.”

The UK Space Agency says that Reaction Engines will carry out an important demonstration of the SABRE engine’s key pre-cooler technology later this summer.

Source: Reaction Engines Ltd.

Gamma Ray Burst 090429B… Far Out!

Credit: Gemini Observatory/AURA/Andrew Levan (University of Warwick, UK)

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You don’t have to be an old hippie… all you have to do is be able to picture a time within about half a billion years after the Big Bang. Thanks to a set of composite images taken by Gemini Observatory North telescope through different optical and infrared filters, science may have discovered what could be the most distant gamma ray burst (GRB) ever detected.

“Like any finding of this sort there are uncertainties,” said the study’s principal investigator Antonino Cucchiara. “However, if I were in Vegas, I would never bet against the odds that this is the most distant GRB ever seen and we estimate that there is even a 23% chance that it is the most distant object ever observed in the universe.”

As we probe further and further into the most distant reaches of space, we’re virtually able to look back in time. Even though gamma ray bursts last only a matter of minutes and occur billions of light years away, their “afterglow” can last for a period of a couple of weeks, allowing instruments like the Swift satellite or large ground-based telescopes to detect them. According to Cucchiara, “Gemini was the right telescope, in the right place, at the right time. The data from Gemini was instrumental in allowing us to reach the conclusion that the object is likely the most distant GRB ever seen.”

If their findings are correct, this implies the light of the distant GRB left from its source some 13.1 billion years ago or about 520 million years after the Big Bang. This allows astronomers to draw a conclusion that it is not the consequence of the very first generation of stars formed in the universe. The implication is that the early, extremely young universe was already a busy star factory.

“By looking very far away, because the light takes so long on its journey to reach the Earth, astronomers are effectively able to look back in time to this early era. Unfortunately, the immense distances involved make this very challenging. There are different ways of finding such objects, looking at distant galaxies being the most obvious, but because galaxies are faint it is very difficult. GRB afterglows are so much brighter”

But arriving at those type of conculsions isn’t easy and that’s why the study took two years to complete. “Ideally we would have gathered a spectrum to measure the distance precisely, but we were foiled at the last minute when the weather took a turn for the worse on Mauna Kea. Since GRB afterglows fade so quickly, we never got a second chance,” said Derek Fox, Cucchiara’s advisor for his graduate research at Penn State University.

Being sure enough to report findings as conclusive can be a tricky business. As with all things astronomy, a second “opinion” is not only welcomed, but a neccessary part of any findings. That’s why Gemini North’s images were combined with wider-field images from the United Kingdom Infrared Telescope (also on Hawaii’s Mauna Kea). As a result, the team was able to estimate the redshift of GRB 090429B with a high degree of confidence.

Credit: Gemini Observatory/AURA/Penn State/UC Berkeley/University of Warwick, UK

“The fact that we were never able to detect anything in the spot where we saw the afterglow in the Gemini data gave us the missing link in converging on this extremely high redshift estimate,” said Cucchiara. “We looked with Gemini, the Hubble Space Telescope and also with the Very Large Telescope in Chile and never saw anything once the afterglow faded. This means that this GRB’s host galaxy is so distant that it couldn’t be seen with any existing telescopes. Because of this, and the information provided by the Swift satellite, our confidence is extremely high that this event happened very, very early in the history of our universe.”

Really far out…

Hubble Finds “Oddball” Stars in Milky Way Hub

Astronomers using the Hubble Space Telescope to peer deep into the central bulge of our galaxy have found a population of rare and unusual stars. Dubbed “blue stragglers”, these stars seem to defy the aging process, appearing to be much younger than they should be considering where they are located. Previously known to exist within ancient globular clusters, blue stragglers have never been seen inside our galaxy’s core – until now.

The stars were discovered following a seven-day survey in 2006 called SWEEPS – the Sagittarius Window Eclipsing Extrasolar Planet Search – that used Hubble to search a section of the central portion of our Milky Way galaxy, looking for the presence of Jupiter-sized planets transiting their host stars. During the search, which examined 180,000 stars, Hubble spotted 42 blue stragglers.

Of the 42 it’s estimated that 18 to 37 of them are genuine.

What makes blue stragglers such an unusual find? For one thing, stars in the galactic hub should appear much older and cooler… aging Sun-like stars and old red dwarfs. Scientists believe that the central bulge of the Milky Way stopped making new stars billions of years ago. So what’s with these hot, blue, youthful-looking “oddballs”? The answer may lie in their formation.

Artist's concept of a blue straggler pair. NASA, ESA, and G. Bacon (STScI)

A blue straggler may start out as a smaller member of a binary pair of stars. Over time the larger star ages and gets even bigger, feeding material onto the smaller one. This fuels fusion in the smaller star which then grows hotter, making it shine brighter and bluer – thus appearing similar to a young star.

However they were formed, just finding the blue stragglers was no simple task. The stars’ orbits around the galactic core had to be determined through a confusing mix of foreground stars within a very small observation area. The region of the sky Hubble studied was no larger than the width of a fingernail held at arm’s length! Still, within that small area Hubble could see over 250,000 stars. Incredible.

“Only the superb image quality and stability of Hubble allowed us to make this measurement in such a crowded field.”

– Lead author Will Clarkson, Indiana University in Bloomington and the University of California in Los Angeles

The discovery of these rare stars will help astronomers better understand star formation in the Milky Way’s hub and thus the evolution of our galaxy as a whole.

Read more on the Hubble News Center.

Image credit: NASAESA, W. Clarkson (Indiana University and UCLA), and K. Sahu (STScI)

In Memoriam: Spirit Rover, 2004-2010

Mars
The sun has set for the Spirit rover on Mars. Credit: NASA

If you’re feeling a little sad today at the news that the Spirit rover is “dead,” you’re not alone. And we all know we’re anthropomorphizing here, but it is hard not to. As MER project manager John Callas said at yesterday’s press conference, the MER rovers are “the cutest darn things out in the solar system,” and yes, we’ve become attached to them. Below are a few quotes we’ve gathered from Steve Squyres, Scott Maxwell, and some of the other people who have been involved with the MER mission in various capacities.

Feel free to add your best memories of Spirit’s mission in the comment section.

Rover Driver Scott Maxwell with a model of MER. Photo courtesy Scott Maxwell

Rover Driver Scott Maxwell. Maxwell has been part of the rover driving team since before the MER rovers lauched. He is publishing the diary he has kept, five years delayed on his Mars and Me blog.

“My take on this is that I know I’m supposed to be sad and I know that at some point I will be really sad, but at the moment it is hard to be sad because that feeling is overwhelmed by the pride of what Spirit accomplished,” Maxwell told Universe Today. “She accomplished an enormous amount in the six years plus that she was active on Mars, and we have every good reason to be proud of her. That is dominating my reaction to this announcement today. It terrible that she’s gone but I’m so proud of her, she did so much, she lived so long and accomplished such great things it’s hard to feel any other way.”

Will Spirit’s official loss put a big hole in Maxwell’s day?

“In terms of my practical day to day operations, not so much,” he said. “My day is filled with taking care of Opportunity and working on the upcoming Mar Science Lab mission, so actually I didn’t have that much to do with Spirit the past year. The way it will affect me is that I won’t be getting the weekly planning schedule for Spirit anymore, so in that way Spirit is going to disappear out of my world.”

Maxwell’s cat died a few months ago he finds he sometimes has an unconscious expectation that the cat will greet him when Maxwell returns home, but then he realizes the cat isn’t there anymore. “That’s the kind of hole that Spirit will leave in my life, where I’ll be unconsciously looking for scheduling emails, or data or information about Spirit, and it is not going to be there, and that place that she has occupied in my life is just not going to be there anymore. I’ve had time to get used to that over the past year, of not actively driving her, so I’ve gone through that transition and I’ll go through this transition next.”

MER PI Steve Squyres. Credit: NASA

Steve Squyres, MER Principal Investigator

“What’s most remarkable to me about Spirit’s mission is just how extensive her accomplishments became,” Squyres said in a JPL press release. “What we initially conceived as a fairly simple geologic experiment on Mars ultimately turned into humanity’s first real overland expedition across another planet. Spirit explored just as we would have, seeing a distant hill, climbing it, and showing us the vista from the summit. And she did it in a way that allowed everyone on Earth to be part of the adventure.”

Squyres said Spirit’s unexpected discovery of concentrated silica deposits was one of the most important findings by either rover.

“It showed that there were once hot springs or steam vents at the Spirit site, which could have provided favorable conditions for microbial life,” he said.

The silica-rich soil was next to a low plateau called Home Plate, which was Spirit’s main destination after the traverse long distances and climbed up and down Husband Hill. “What Spirit showed us at Home Plate was that early Mars could be a violent place, with water and hot rock interacting to make what must have been spectacular volcanic explosions. It was a dramatically different world than the cold, dry Mars of today,” said Squyres.

Chris Potts points to Gusev Crater on Mars on January 4, 2004, after the MER navigation team landed the Spirit rover on Mars with unprecedented accuracy. Photo courtesy of Chris Potts

Chris Potts was the Deputy Navigation Team Chief for both MER rovers.

“My thoughts immediately go back to the night Spirit landed in Gusev Crater on Jan. 3, 2004,” Potts told Universe Today. “It was a nerve wracking evening, thinking about the dangers involved with bringing Spirit from 12,000 mph to a safe landing via menacing bounces inside the airbags. No one could dare imagine that Spirit would continue on to explore Mars for over 6 years. Such an engineering feat requires the best from everyone involved, from the early designers to the operations team that extracted every last bit that Spirit had to offer. Spirit overcame so many obstacles on the journey, that the rover seemed to have a destiny that would not be denied. Spirit has finally reached the inevitable mission end, but I like to imagine the future when space tourists will follow Spirit’s tracks and continue to marvel at what the rover was able to accomplish.”

Doug Ellison, founder of UnmannedSpaceflight.com, where imaging enthusiasts get together to work with data being produced by robotic missions. He started the website, in part, because of the remarkable images being returned by the MER mission.

“I’ve been trying to figure out the words to describe how it feels,” Ellison told Universe Today. “Like losing a family member isn’t that short of the mark. When those early raw JPG’s were put onto their website so quickly I just couldn’t help myself. I found myself making color composites, panoramas, anaglyphs…and that’s what triggered the making of what became UMSF. It’s been a 7 year adventure that’s been shared through more than 125,000 images. We all lived that adventure through those pictures, together.”

Ellison said it is heartbreaking to see Spirit’s part of the mission come to an end. “Mars always had the power to end things, and she did, on her terms and not ours,” he said. “That’s as it should be, Spirit went down fighting in the battle against freezing temperatures on a barren near airless planet. My only regret is that we’ll never truly know exactly what caused Spirit to stay quiet.”

“We think of ‘Spirit’ as that robot on Mars,” he continued. “Without the team of scientists and engineers here on the ground who figured out what to do with that robot, the adventure we’ve been on, together, would never have happened. She’s part of this large team. She’s the teams feet with every drive she made. She’s their eyes with every picture she took. She’s their hands with every rock she studied. And, for many of us, she’s also its heart. The sol-to-sol rhythm of seeing new pictures and planning new adventures was the heartbeat of this large family that wasn’t just the mission personnel at JPL, Cornell and elsewhere – it wasn’t even just Spirit – it was all of us. That family was the thousands and thousands of people who followed along all over the world, it was the robot that did the dirty work, the engineers who kept her safe and the scientists who made the most of her. That family is now one member short – but it still exists. It formed around this little robot called Spirit, and will carry on through other projects.”

“Spirit didn’t die. She just moved on. I feel so very very sorry for the engineers who spent so long designing, building, and then for more than 6 years, using that little robot. But most of all, I feel sorry for Curiosity. As someone at UMSF suggested – that rover’s now sat in the clean room thinking ‘How the heck am I supposed to follow an act like that?'”

Neil Mottinger.

Neil Mottinger from JPL worked on the navigation team for the launch and trajectory of the two spacecraft that brought Spirit and Opportunity to Mars.

“It’s an incredible testimony to engineering that this plucky little craft survived 3 winters, when it wasn’t designed to survive any such weather conditions at all,” Mottinger told Universe Today. “Dust storms didn’t drown its ability to generate electricity thanks to the dust devils that repeatedly cleaned the panels. May its tenacity remind us all to strive for greater goals and push on way beyond the immediate horizons before us.”

Stu Atkinson, member of UMSF, poet and writer penned this poem about the end of Spirit’s mission. You can also read a short story he wrote about a year ago of what could have happened in some households when Spirit died.

MER Project Manager John Callas. Credit: JPL

John Callas has written a letter to his MER team, and in part said, “But let’s remember the adventure we have had. Spirit has climbed mountains, survived rover-killing dust storms, rode out three cold, dark winters and made some of the most spectacular discoveries on Mars. She has told us that Mars was once like Earth. There was water and hot springs, the conditions that could have supported life. She has given us a foundation to further explore the Red Planet and to understand ourselves and our place in the universe.

“But in addition to all the scientific discoveries Spirit has given us in her long, productive rover life, she has also given us a great intangible. Mars is no longer a strange, distant and unknown place. Mars is now our neighborhood. And we all go to work on Mars every day. Thank you, Spirit. Well done, little rover. And to all of you, well done, too.”

We’ll be adding more quotes about Spirit as they come in.