Posted on by Nancy Atkinson

One More Item Found in Astounding HiRise Image of Phoenix Descending

Remember the amazing image that the HiRISE Camera on the Mars Reconnaissance Orbiter captured of the Phoenix Lander as it descended to Mars’ surface via parachute back on May 25? Well, the HiRISE scientists have done a little more processing of the image, and have turned up an additional detail they didn’t see at first: Phoenix’s heat shield. The heat shield, which had been jettisons just after parachute deployment, can be seen falling toward the surface. You have to look really, really close to see it. But that’s what these HiRISE folks do. It was incredible that they found the lander with the parachute in the image (go see the big, huge image they had to hunt for it HERE) and these guys get the eagle eyes of the year award for finding the heat shield.

HiRISE made history by taking the first image of a spacecraft as it descended toward the surface of another planetary body. Here’s the image again:

The image shows NASA’s Phoenix Mars Lander when the spacecraft was still tucked inside its aeroshell, suspended from its parachute, at 4:36 p.m. Pacific Daylight Time on landing day. Although Phoenix appears to be descending into an impressive impact crater, it actually landed 20 kilometers, or 12 miles, away.

Mars Reconnaissance Orbiter was about 760 kilometers, or 475 miles, away when it pointed the HiRISE camera obliquely toward the descending Phoenix lander. The camera viewed through the hazy Martian atmosphere at an angle 26 degrees above the horizon when it took the image. The 10-meter, or 30-foot, wide parachute was fully inflated. Even the lines connecting the parachute and aeroshell are visible, appearing bright against the darker, but fully illuminated Martian surface.

In further analyzing the image, the HiRISE team discovered a small, dark dot located below the lander.
Phoenix was equipped with a heat shield that protected the lander from burning up when it entered Mars’ atmosphere and quickly decelerated because of friction. Phoenix discarded its heat shield after it deployed its parachute.

“Given the timing of the image and of the release of the heat shield, as well as the size and the darkness of the spot compared to any other dark spot in the vicinity, we conclude that HiRISE also captured Phoenix’s heat shield in freefall,” said HiRISE principal investigator Alfred McEwen.

The multigigabyte HiRISE image also includes a portion recorded by red, blue-green and infrared detectors, and scientists have processed that color part of the image.

HiRISE’s color bands missed the Phoenix spacecraft but do show frost or ice in the bowl of the relatively recent, 10-kilometer (6-mile) wide impact crater unofficially called “Heimdall.” The frost shows up as blue in the false-color HiRISE data, and is visible on the right wall within the crater.

The HiRISE camera doesn’t distinguish between carbon dioxide frost and water frost, but another instrument called CRISM on the Mars Reconnaissance Orbiter could.

News Source: SpaceRef

Posted on by Nancy Atkinson

Phoenix Relegated to Scraping the Sidewalk

If humans ever build a city on Mars, perhaps (in its retirement) the Phoenix Lander can apply for a job with the city’s public works department to scrape ice off sidewalks. Phoenix has been trying to dig down deeper into the “Snow White” trench and has been digging, scooping and scraping the ice layer that earlier soil scooping exposed. The robotic arm team is working to get an icy sample into the Robotic Arm scoop for delivery to the Thermal and Evolved Gas Analyzer (TEGA). Ray Arvidson of the Phoenix team, known as the “dig czar,” said the hard Martian surface that Phoenix has reached is proving to be a difficult target, and compared the process to scraping a sidewalk. “We have three tools on the scoop to help access ice and icy soil,” Arvidson said. “We can scoop material with the backhoe using the front titanium blade; we can scrape the surface with the tungsten carbide secondary blade on the bottom of the scoop; and we can use a high-speed rasp that comes out of a slot at the back of the scoop.”

“We expected ice and icy soil to be very strong because of the cold temperatures. It certainly looks like this is the case and we are getting ready to use the rasp to generate the fine icy soil and ice particles needed for delivery to TEGA,” he said.

Scraping action produced piles of scrapings at the bottom of a trench on Monday, but did not get the material into its scoop, evidenced from images returned to Earth by the lander. The piles of scrapings produced were smaller than previous piles dug by Phoenix, which made it difficult to collect the material into the Robotic Arm scoop.

“It’s like trying to pick up dust with a dustpan, but without a broom,” said Richard Volpe, an engineer from NASA’s Jet Propulsion Laboratory, Pasadena, Calif., on Phoenix’s Robotic Arm team.

The mission teams are now focusing on use of the motorized rasp within the Robotic Arm scoop to access the hard icy soil and ice deposits. They are conducting tests on Phoenix’s engineering model in the Payload Interoperability Testbed in Tucson to determine the optimum ways to rasp the hard surfaces and acquire the particulate material produced during the rasping. The testbed work and tests on Mars will help the team determine the best way to collect a sample of Martian ice for delivery to TEGA.

The Phoenix team also continues to analyze results from the Wet Chemistry Lab, as a sample was delivered to the lab on July 6. Results should be forthcoming.

News Source: Phoenix News

Posted on by Astronomy Cast

Podcast: Humans to Mars, Part 3 – Terraforming Mars

Artist impression of terraformed Mars. Image credit: NASA

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And now we reach the third part of our trilogy on the human exploration and colonization of Mars. Humans will inevitably tire of living underground, and will want to stretch their legs, and fill their lungs with fresh air. One day, we’ll contemplate the possibility of reshaping Mars to suit human life. Is it even possible? What technologies would be used, and what’s the best we can hope for?

Click here to download the episode

Humans to Mars, Part 3 – Terraforming Mars – Show notes and transcript

Or subscribe to: astronomycast.com/podcast.xml with your podcatching software.

Posted on by Nancy Atkinson

Phoenix Brings New Sample to Wet Chemistry Lab

The Phoenix Mars Lander used its robotic arm to deliver a second sample of soil for analysis by the spacecraft’s wet chemistry laboratory. Data received from Phoenix on Sunday night confirmed the soil was in the lab’s cell number 1. This image taken by the the lander’s Surface Stereo Imager shows the Robotic Arm scoop positioned over the Wet Chemistry Lab Cell 1 delivery funnel on Sol 41, or July 6. Test results will be compared in coming days to the results from the first Martian soil analyzed by the wet chemistry laboratory two weeks ago. That laboratory is part of Phoenix’s Microscopy, Electrochemistry and Conductivity Analyzer.



On Monday, Phoenix also tested a method for scraping up a sample of icy material and getting it into the scoop at the end of the robotic arm. Photography before, during and after the process will allow evaluation of this method. If the test goes well, the science team plans to use this method for gathering the next sample to be delivered to Phoenix’s bake-and-sniff instrument, the Thermal and Evolved-Gas Analyzer (TEGA). The science team wants to be as precise and quick as possible in delivering the next sample to TEGA, as it possibly could be the last time the ovens can be used because of a short circuit that may occur the next time the oven is activated.

News Source: U of Arizona

Posted on by Nancy Atkinson

International Group Studies Mars Sample Return Mission

Until humans can actually set foot on the Red Planet, the next best thing would be a sample return mission, to bring Martian soil samples back to Earth. A sample return would exponentially increase our knowledge and understanding Mars and its environment. And in order to pull off a mission of this magnitude, international cooperation might be required, and in fact, may be preferred. The International Mars Exploration Working Group (IMEWG), organized an international committee to study an international architecture for a Mars Sample Return (MSR) mission concept. After several months of collective work by scientists and engineers from several countries worldwide, the “iMARS” group is ready to publish the outcome of its deliberations and the envisioned common architecture for a future international MSR mission, and they will discuss their findings at an international conference on July 9 and 10 in France.

The conference will be held at the Auditorium of the Bibliothèque Nationale de France in Paris, and will bring together members of the scientific and industrial communities as well as representatives of space agencies around the world to discuss the status and prospects for Mars exploration over the coming decades. Attendees will have the opportunity to hear the current international thinking on Mars Sample Return and to interact with key players in the global endeavor of exploring and understanding Mars.

A Mars Sample Return mission would use robotic systems and a Mars ascent rocket to collect and send samples of Martian rocks, soils, and atmosphere to Earth for detailed chemical and physical analysis. Researchers on Earth could measure chemical and physical characteristics much more precisely than they could by via remote control. On Earth, they would have the flexibility to make changes as needed for intricate sample preparation, instrumentation, and analysis if they encountered unexpected results. In addition, for decades to come, the collected Mars rocks could yield new discoveries as future generations of researchers apply new technologies in studying them.

Keynote speakers at the upcoming conferencewill are Steve Squyres of Cornell University, principal investigator under the MER mission, and Jean-Pierre Bibring of the Institut d’Astrophysique Spatiale, principal investigator for a key instrument on Mars Express.

Interested in attending? Check out their website

Original News Source: ESA

Posted on by Nancy Atkinson

Next TEGA “Bake” Could Be Last for Phoenix

The “vibrating” done to get the first Mars arctic soil sample into Phoenix’s TEGA (Thermal and Evolved Gas Analyzer) oven may have caused a short circuit that could happen again the next time the oven is used, perhaps with fatal results. A team of engineers and scientists assembled to assess TEGA after a short circuit was discovered in the instrument, and came to a fairly disheartening conclusion. “Since there is no way to assess the probability of another short circuit occurring, we are taking the most conservative approach and treating the next sample to TEGA as possibly our last,” said Peter Smith, Phoenix’s principal investigator. Therefore, the Phoenix team is doing everything they can to assure the next sample delivered to TEGA will be ice-rich.

The short circuit was believed to have been caused when TEGA’s oven number four was vibrated repeatedly over the course of several days to break up clumpy soil so that it could get inside the oven. Delivery to any TEGA oven involves a vibration action, and turning on the vibrator in any oven will cause oven number 4 to vibrate as well, which could cause a short.

A sample taken from the trench called “Snow White” that was in Phoenix’s robotic arm’s scoop earlier this week likely has dried out, so the soil particles are to be delivered to the lander’s optical microscope on Thursday. If material remains in the scoop, the rest will be deposited in the Wet Chemistry Laboratory, possibly early on Sunday.

The mission teams will mark the Independence Day holiday with a planned “stand down” from Thursday morning, July 3, to Saturday evening, July 5. A skeleton crew at the University of Arizona in Tucson, at NASA’s Jet Propulsion Laboratory in Pasadena, Calif., and Lockheed Martin Space Systems in Denver, Colo., will continue to monitor the spacecraft and its instruments over the holiday period.

“The stand down is a chance for our team to rest, but Phoenix won’t get a holiday,” Smith said. The spacecraft will be operating from pre-programmed science commands, taking atmospheric readings and panoramas and other images.

Once the sample is delivered to the chemistry experiment, Smith said the highest priority will be obtaining the ice-rich sample and delivering it to TEGA’s oven number zero.

The Phoenix team will conduct tests and trial runs so the instruments can deliver the icy sample quickly, in order to avoid sublimation of materials during the delivery process, so the solid ice doesn’t vaporize.

Original News Source: Phoenix News

Posted on by Ian O'Neill

“Almost Perfect” Samples are Scraped From Mars Surface For Analysis

The tranch called Snow White where the scrapes of ice and soil were extracted (NASA/UA)

With the Phoenix Mars lander in full science-operation-swing, the robotic arm has just scraped an “almost perfect” mix of regolith and water ice for its next analysis. Using a blade on the scoop, the robotic arm carried out 50 scraping actions across the bottom of the enlarged “Snow White” trench that was excavated on June 17th (22 sols since Phoenix touched down). Today, on Sol 33 of the mission, Phoenix has been preparing little mounds of dirt ready to be scooped up and dropped into the Thermal and Evolved-Gas Analyzer (TEGA) so the constituent minerals and water can be analysed. Besides, Phoenix has just built the first ever mini-sand castles on the Martian surface!

On Sol 24 of the mission, only 24 sols after it landed on Mars, Phoenix found the first evidence of water ice on the Martian surface. Pictures taken four sols apart showed a white substance had sublimed into the tenuous Martian atmosphere at about the correct rate for water ice under those conditions. This was after a bumpy start when the clumpy regolith didn’t make it past the TEGA screen in a preliminary oven experiment. Then last week, Phoenix carried out a preliminary “wet-lab” test with the Microscopy, Electrochemistry and Conductivity Analyzer (MECA) instrument and found the mix of minerals in the Mars regolith and its pH levels had a striking resemblance with soils commonly found here on Earth. With all these groundbreaking discoveries mounting up, what can we expect next?

Well, today’s announcement suggests the next step is to thoroughly prepare small piles of samples scraped from the bottom of a trench called “Snow White” dug on Sol 22. Once this is complete, each sample (containing approximately two to four teaspoonfuls) can then be sprinkled into the TEGA instrument so thorough analysis can take place. The bottom of Snow White appears to be rich in water ice, so the scraping action will have created small particles of regolith and small ice crystals. Having encountered the clumpiness of regolith before, the mission scientists are keen to push ahead with some flawless experiments.

Having overviewed the small samples, agreeing that the piles were “almost perfect samples of the interface of ice and soil,” Phoenix has been sent commands to scoop up each pile of dirt and sprinkle them into the TEGA. The instrument will then bake and analyse the soil to assess its volatile ingredients, like water. The melting point of the water ice can also be assessed. Once the data has been transmitted back to Earth scientists can begin to study the constituents of the sub-surface regolith, gaining a detailed look into just how hospitable the Red Planet could be.

Keep making those little sand castles Phoenix, we’re watching you very closely…

Source: Phoenix (University of Arizona)

Posted on by Ian O'Neill

Phoenix: Mars Soil Can Support Life

Phoenix delivers regolith to the wet lab (NASA/UA)

Another groundbreaking discovery from Mars: Phoenix has analysed martian regolith containing minerals more commonly found in soil here on Earth, and the acidity is not a hindrance for life to thrive. These new and very exciting results come after preliminary analyses of a scoop of regolith by the landers “wet lab” known as the Microscopy, Electrochemistry and Conductivity Analyzer (MECA) instrument. Although more data collecting needs to be done, trace levels of nutrients have already been detected. This, with the recent discovery of water ice, has amazed mission scientists, likening these new results to “winning the lottery.”

The MECA instrument is carrying out the first ever wet-chemical analysis on a planet other than Earth, and these first results are tantalisingly close to providing answers for the question: “Can Mars support life?” Taken from a scoop of top-soil, the robotic digger managed to excavate a 2 cm deep ditch, delivering the sample to the MECA where analysis could be carried out. The first results from the two-day wet-lab experiment are flooding in and mission scientists are excited by the results. “We are awash in chemistry data,” said Michael Hecht of NASA’s Jet Propulsion Laboratory and lead scientist for the MECA.

The salts discovered contain magnesium, sodium, potassium and chlorine, indicating these minerals had once been dissolved in water. The knowledge that these elements exist in martian regolith is nothing new, but the fact that they would be soluble in water means they would have been available for life to form. In fact, there are some strong similarities between the mineral content and pH level of the martian surface and soils more commonly found here on Earth.

“This soil appears to be a close analog to surface soils found in the upper dry valleys in Antarctica. The alkalinity of the soil at this location is definitely striking. At this specific location, one-inch into the surface layer, the soil is very basic, with a pH of between eight and nine. We also found a variety of components of salts that we haven’t had time to analyze and identify yet, but that include magnesium, sodium, potassium and chloride.” – Sam Kounaves, Phoenix co-investigator, Tufts University.

From the question “Has Mars supported life?” to “Can Mars support life?” – The answer seems to be an overwhelming “Yes.” Although nitrates have yet to be detected, the Mars soil appears to have an alkalinity commonly found in terrestrial soils. At a pH of eight or nine, a zoo of bacteria and plants can live comfortably. Vegetables such as asparagus and turnips are farmed in soils to this degree of alkalinity. Besides, extreme forms of bacteria have been discovered in environments that resemble the alkalinity of bleach, exceeding a pH of 12. The martian surface has suddenly become a little more hospitable for life to thrive.

“Over time, I’ve come to the conclusion that the amazing thing about Mars is not that it’s an alien world, but that in many aspects, like mineralogy, it’s very much like Earth.” – Kounaves.

Although these first results are very exciting, mission scientists are staying realistic. This is only one of several tests, plus it is a sample from a single location. As the digger only scooped a sample 2 cm deep, scientists are keen to see if the regolith deeper down has similar chemistry, so the intention is to dig deeper into the same location, possibly including ice.

Aside: The term “Mars soil”, up to this point, hasn’t been technically accurate. If we look at the definition of “soil” we get:

The material on the surface of the ground in which plants grow; earth
– Cambridge Dictionaries.
The top layer of the earth’s surface, consisting of rock and mineral particles mixed with organic matter.
– Answers.com

The stuff with a red hue on Mars is actually regolith, pulverized grains of rock from hundreds of millions of years of meteorite impacts, geological activity and weathering. Until Phoenix produced these new findings, the most accurate way to describe Mars “soil” was to call it regolith. But now, it seems, Mars regolith fulfils most of the characteristics of being a soil. It contains rock, it contains minerals and it appears to have a pH capable of sustaining plant growth. But does it already contain organic matter? Whether it contains anything “organic” now is open to debate, but it might do in the future…

Sources: Phoenix (UA), New Scientist

Posted on by Nancy Atkinson

Two Faces of Mars Explained

Mars has two faces. No, not those kind of faces, but the notable differences between the northern and southern hemisphere. Mars has lowlands in the north and highlands in the south. This disparity has long puzzled planetary scientists, but most concurred that early in Mars history, impacts shaped the planet’s two-faced landscape. But many disagreed whether several small impacts or one big one were responsible for sculpting Mars’ surface. Now scientists at the California Institute of Technology have shown through computer modeling that the Mars dichotomy, as the divided terrain has been termed, can indeed be explained by one giant impact early in the planet’s history.

“The dichotomy is arguably the oldest feature on Mars,” said Oded Aharonson from Caltech. Scientists believe the differences in hemispheric features arose more than four billion years ago.

Previously, scientists discounted the idea that a single, giant impactor created the lower elevations and thinner crust of Mars’s northern region, says Margarita Marinova, a graduate student at Caltech, and one of the lead authors of the study.

For one thing, Marinova explained, it was thought that a single impact would leave a circular footprint, but the outline of the northern lowlands region is elliptical. There is also a distinct lack of a crater rim: topography increases smoothly from the lowlands to the highlands without a lip of concentrated material in between, as is the case in small craters. Finally, it was believed that a giant impactor would obliterate the record of its own occurrence by melting a large fraction of the planet and forming a magma ocean.

“We set out to show that it’s possible to make a big hole without melting the majority of the surface of Mars,” Aharonson says. The team modeled a range of projectile parameters that could yield a cavity the size and ellipticity of the Mars lowlands without melting the whole planet or making a crater rim.

The team ran over 500 computer simulations combining various energies, velocities, and impact angles. Finally, they were able to narrow in on a “sweet spot”–a range of single-impact parameters that would make exactly the type of crater found on Mars. Their dedicated supercomputer allowed them to run simulations not run in the past. “The ability to search for parameters that allow an impact compatible with observations is enabled by the dedicated machine at Caltech,” Aharonson said.

The favored simulation conditions outlined by the sweet spot suggest an impact energy of around 1029 joules, which is equivalent to 100 billion gigatons of TNT. The impactor would have hit Mars at an angle between 30 and 60 degrees while traveling at 6 to 10 kilometers per second. By combining these factors, Marinova calculated that the projectile was roughly 1,600 to 2,700 kilometers across.

Estimates of the energy of the Mars impact place it squarely between the impact that is thought to have led to the extinction of dinosaurs on Earth 65 million years ago and the one believed to have extruded our planet’s moon four billion years ago.

Marinova said the timing of formation of our moon and the Mars dichotomy is not coincidental. “This size range of impacts only occurred early in solar system history,” she says. The results of this study are also applicable to understanding large impact events on other heavenly bodies, like the Aitken Basin on the moon and the Caloris Basin on Mercury.

This report, published in the June 26 issue of Nature, goes along with two other papers on the Mars dichotomy. One published by Jeffrey Andrews-Hanna and Maria Zuber of MIT and Bruce Banerdt of JPL examine the gravitational and topographic signature of the dichotomy with information from the Mars orbiters. Another accompanying report, from a group at UC Santa Cruz led by Francis Nimmo, explores the expected consequences of mega-impacts.

Original News Source: EurekAlert

Posted on by Nancy Atkinson

Mars Atmosphere Once Held Enough Moisture for Dew or Drizzle

Data from Mars orbiters and landers have suggested that any past water on the Red Planet’s surface probably came from subsurface moisture bubbling up from underground. But a new study of Martian soil data implies that Mars’ atmosphere was once thick enough to hold moisture and that dew or even drizzle hit the ground. Geoscientists at the University of California Berkeley combined data from the Viking 1 and 2 landers, the Pathfinder rover, and the current rovers Spirit and Opportunity. The scientists say tell-tale signs of this type of moisture are evident on the planet’s surface.

“By analyzing the chemistry of the planet’s soil, we can derive important information about Mars’ climate history,” said Ronald Amundson, UC Berkeley professor of ecosystem sciences and the study’s lead author. “The dominant view, put forward by many now working on the Mars missions, is that the chemistry of Mars soils is a mix of dust and rock that has accumulated over the eons, combined with impacts of upwelling groundwater, which is almost the exact opposite of any common process that forms soil on Earth. In this paper, we try to steer the discussion back by re-evaluating the Mars data using geological and hydrological principles that exist on Earth.”

The team says soil at the various spacecraft landing sites have lost significant fractions of the elements that make up the rock fragments from which the soil was formed. This is a sign, they say, that water once moved downward through the dirt, carrying the elements with it. Amundson also pointed out that the soil also shows evidence of a long period of drying, as evidenced by surface patterns of the now sulfate-rich land. The distinctive accumulations of sulfate deposits are characteristic of soil in northern Chile’s Atacama Desert, where rainfall averages approximately 1 millimeter per year, making it the driest region on Earth.

Researchers compared images such as this image of the Atacama Desert with the above image taken by the Opportunity rover on Mars, which show similar surface patterns.

“The Atacama Desert and the dry valleys of Antarctica are where Earth meets Mars,” said Amundson. “I would argue that Mars has more in common geochemically with these climate extremes on Earth than these sites have in common with the rest of our planet.”

Amundson noted that sulfate is prevalent in Earth’s oceans and atmosphere, and is incorporated in rainwater. However, it’s so soluble that it typically washes away from the surface of the ground when it rains. The key for the distinctive accumulation in soil to appear is for there to be enough moisture to move it downward, but not so much that it is washed away entirely.

The researchers also noted that the distribution of the chemical elements in Martian soil, where sulfates accumulate on the surface with layers of chloride salt underneath, suggest atmospheric moisture.

“Sulfates tend to be less soluble in water than chlorides, so if water is moving up through evaporation, we would expect to find chlorides at the surface and sulfates below that,” said Amundson. “But when water is moving downward, there’s a complete reversal of that where the chlorides move downward and sulfates stay closer to the surface. There have been weak but long-term atmospheric cycles that not only add dust and salt but periodic liquid water to the soil surface that move the salts downward.”

Amundson pointed out that there is still debate among scientists about the degree to which atmospheric and geological conditions on Earth can be used as analogs for the environment on Mars. He said the new study suggests that Martian soil may be a “museum” that records chemical information about the history of water on the planet, and that our own planet holds the key to interpreting the record.

“It seems very logical that a dry, arid planet like Mars with the same bedrock geology as many places on Earth would have some of the same hydrological and geological processes operating that occur in our deserts here on Earth,” said Amundson. “Our study suggests that Mars isn’t a planet where things have behaved radically different from Earth, and that we should look to regions like the Atacama Desert for further insight into Martian climate history.”

Original News Source: EurekAlert