Category: Mars

Phoenix’s scientific team team held a press conference today to officially make their big announcement, which was fairly evident from pictures on the Phoenix website late yesterday: They found what they have been looking for. “It is with great pride and lot of joy that announce today we have found the proof that we have been seeking that show that this hard, white material is water ice,” said the project’s principle investigator Peter Smith. The image here shows a trench dug by Phoenix’s robotic arm scoop that exposed a white area, and left a couple of small chunks of white material, which scientists thought could possibly be ice. A few days later, the ice is gone. “In the course of sitting through the cold and very dry Martian environment for several days, it sublimated,” said Mark Lemmon, co-investigator on the Phoenix’s Surface Stero Imager. “The ice went away into vapor without any melting taking place.” But how do the scientists know for sure this is water ice?

“We can easily and confidently rule out that its carbon dioxide ice,” said Lemmon. “There are certainly times of the year that there would be CO2 ice at this location but with the temperatures we are measuring there, it would be the equivalent of water ice existing on Earth at 140 degrees. It wouldn’t be there very long, and wouldn’t be there long enough for us to take its picture, and it wouldn’t last the night. We’re very confident this is not CO2 ice. We’re ruling out salt, because salt doesn’t react like this. We’re confident now that this is water ice. We’ve hit what we’re looking for. The job now is to find out what is mixed in with the ice, how much salt is there, how many organics are there, and these are the things we’ll need TEGA and MECA to solve.”

TEGA is the Thermal and Evolved Gas Analyzer that “bakes and sniffs” out the chemical composition of the soil, and MECA is Microscopy, Electrochemistry and Conductivity Analyzer, a wet chemistry lab that measures levels of acidity, minerals, and conductivity in dirt samples.

Smith said the landing site was carefully chosen as a place where ice was very likely to exist, based on subsurface hydrogen detected by the orbiting 2001 Mars Odyssey spacecraft.

The team is now going to look for two things associated with the ice. “Does the ice melt, and does the melted ice environment allow a habitable zone on Mars,” said Smith. “That is a place where organic material and energy sources combined with liquid water can be a habitat for Martian life. We don’t have instruments that detect life itself. We’re looking at this stage for habitability, and it will be future missions that will look for life.”

The trick now is to get some of this white material into the TEGA instrument ovens before it sublimates. “The plan for sampling the ice is to gather it up rather quickly using the power tool called the Rasp and deliver it to the TEGA within 30 minutes,” said Ray Arvidson of the Phoenix team. The TEGA ovens do have airtight seal so it’s possible that the ice could go to a liquid stage while being heated. However, because of Mars low surface pressure, the boiling point of water on Mars is 4 Celsius.
Now that they know the ice is there, the scientists want to know more about the soil and why it seems to have a sticky, clumpy consistency. “Knowing that this is ice here, it allows you to speculate there are certain salts that mixed with ice can melt at low temperatures” said Smith. It’s very tempting to get a sample of this into MECA as soon as we can. Right now we have some speculations but no real interpretations available yet. I truly believe we will have answers for you by the end of the summer and hopefully earlier, so stick with us.”

The robotic arm is now digging in a new area in the trench called Snow White. They’ve dug a double trench and have hit a hard layer of ice. The team will try other techniques to see how hard the ice is, and how deep it goes, and try to dig down deeper. They will take their time, however, to make sure the sequences they use for the scraper and rasper work correctly (so as not to repeat having delays similar to what happened the first time they tried getting the soil into TEGA.)

Project manager Barry Goldman also said that the problem with Phoenix’s memory is understood, and two software patches being created to solve the problem of that used up all the space on Phoenix’s version of a flash drive.

Source: Phoenix Press Conference

Phoenix scientists have been keeping an eye on the white material uncovered in a trench dug by the lander’s scoop. Dice-size nuggets of the bright material have vanished, convincing scientists the material was frozen water that vaporized after digging exposed it. The image here is a “movie” showing the material disappearing after four days. “It must be ice,” said Phoenix Principal Investigator Peter Smith. “These little clumps completely disappearing over the course of a few days, that is perfect evidence that it’s ice. There had been some question whether the bright material was salt. Salt can’t do that.”

The chunks were found at the bottom of a trench informally called “Dodo-Goldilocks” when Phoenix’s Robotic Arm enlarged that trench on June 15, during the 20th Martian day, or sol, since landing. Several were gone when Phoenix looked at the trench early today, on Sol 24.

“We know the ice is H2O but that doesn’t tell us much,” Smith said. “It is the impurities in the ice and the soil above the ice that tell us the history and if it is a habitable environment. We’ll now proceed to get the secrets out of the ice and use our instruments.”

Also on Thursday engineers said while digging in a different trench, the Robotic Arm connected with a hard surface that has scientists excited about the prospect of next uncovering an icy layer. Ray Arvidson, co-investigator for the robotic arm, said the hard layer was at the same depth as the ice layer in our the Dodo-Goldilocks trench.

The new trench, called “Snow White 2” trench, is in the middle of a polygon at the “Wonderland” site. While digging, the Robotic Arm came upon a firm layer, and after three attempts to dig further, the arm went into a holding position. Such an action is expected when the Robotic Arm comes upon a hard surface.

The Phoenix science team spent also Thursday analyzing new images and data successfully returned from the lander earlier in the day.

Meanwhile, Phoenix apparently suffered a problem with its flash memory on Tuesday, similar to, but not as serious as the problem that the Spirit Mars Exploration Rover encountered about 20 days after it landed on Mars back in 2004. The spacecraft team at Lockheed Martin Space Systems in Denver is preparing a software patch to send to Phoenix so scientific data can again be saved onboard overnight when needed. Because of a large amount a duplicative file-maintenance data generated by the spacecraft Tuesday, the team is taking the precaution of not storing science data in Phoenix’s flash memory, and instead downlinking it at the end of every day, until the conditions that produced those duplicative data files are corrected.

“We now understand what happened, and we can fix it with a software patch,” said Phoenix Project Manager Barry Goldstein of NASA’s Jet Propulsion Laboratory, Pasadena. “Our three-month schedule has 30 days of margin for contingencies like this, and we have used only one contingency day out of 24 sols. The mission is well ahead of schedule. We are making excellent progress toward full mission success.”

The Phoenix team will hold a press conference today (Friday) at 1:00 pm EST to discuss the latest findings.

Sources: Phoenix News
The Tucson Citizen

The Phoenix lander began digging in an area called “Wonderland” early Tuesday, taking its first scoop of soil from a polygonal surface feature within the “national park” region that mission scientists have been preserving for science. The lander’s Robotic Arm created the new test trench called “Snow White” on June 17, the 22nd Martian day, or sol that Phoenix has been on the Red Planet. However, all of the newly planned science activities will resume no earlier than Sol 24 as engineers look into how the spacecraft is handling larger than expected amounts of data.

During Tuesday’s dig, the arm didn’t reach the hard white material, possibly ice, which Phoenix exposed previously in the first trench it dug into the Martian soil. This trench was only 2 centimeters deep, and the previous trench (the Goldilocks-Dodo Trench) was about 5 cm deep.

So, scientists weren’t surprised at this, and in fact, finding no ice is what they expected and wanted. The Snow White trench is near the center of a relatively flat hummock, or polygon, named “Cheshire Cat,” where scientists predict there will be more soil layers or thicker soil above possible white material.

The Phoenix team plans at least one more day of digging deeper into the Snow White trench. They will study soil structure in the Snow White trench to decide at what depths they will collect samples from a future trench planned for the center of the polygon.

Meanwhile, the Thermal and Evolved-Gas Analyzer (TEGA) instrument continues its ongoing experiment in the first of its eight ovens, and the science team hasn’t yet released any data on the “cooking” at higher temperatures.

TEGA has eight separate tiny ovens to bake and sniff the soil to look for volatile ingredients, such as water. The baking is performed at three different temperature ranges. At the first two temperature ranges, TEGA didn’t detect any water molecules or organics in the soil.

News Source: Phoenix News

The Phoenix lander team revealed the latest images from the mission at a press briefing on Friday. This first image shows an area dug by Phoenix’s scoop, which disclosed a bright surface just a few inches down, which may be ice. “There’s still some debate about the bright material,” said Phoenix Principle Investigator Peter Smith. “Not everyone is sure that this is ice. So there’s been some debate on our team, centering around that perhaps there’s a salt layer just under the soil that also would be bright. Everyone does believe there’s ice under the surface, and whether this is ice or not is the question. The other question is, is this thick ice that goes down deep beneath the surface, or is this a thin layer and we’ll be able to scrape through? So being able to scrape with our scoop is a high priority for us.”


This pair of images taken by the Optical Microscope on NASA’s Phoenix Mars Lander offers a side-by-side comparison of an airfall dust sample collected on a substrate exposed during landing (left) and a soil sample scooped up from the surface of the ground beside the lander. In both cases the sample is collected on a silicone substrate, which provides a sticky surface holding sample particles for observation by the microscope.

Similar fine particles at the resolution limit of the microscope are seen in both samples, indicating that the soil has formed from settling of dust.

The microscope took the image on the left during Phoenix’s Sol 9 (June 3, 2008), or the ninth Martian day after landing. It took the image on the right during Sol 17 (June 11, 2008).

The scale bar is 1 millimeter (0.04 inch).

This is the latest color image of Phoenix, its surroundings and the scoop with soil.

While we can’t look inside the Thermal and Evolved Gas Analyzer (TEGA) oven which will “bake” the Martian soil to test the type of gases that are released, we can see that some of the soil has gone into TEGA. “We were finally successful and some of the material has slid down over the screen” said Smith, “sort of like material going over a cheese grater, and some of the material has slid down and filled the oven. We sent the commands for the first operation of TEGA last night, but we don’t have our data back yet, so we can’t report on any results. That will be coming later next week. So this is a very exciting time for us. We find the soil is very clumpy, it’s sticky, it’s an unusual soil not at all like the types of soils we used in our tests, which worked just fine with all the instruments. So we’ve developed another method of collecting samples, which is to tilt the scoop and vibrate it, and so it shakes down a small amount of material onto the instruments.”

And finally, here’s the latest weather report for Mars, on the 17th sol of Phoenix’s stay on Mars.

Sources: Phoenix News, NASA TV

When Bill Boynton announced at a Phoenix lander team meeting earlier today that the troublesome, clumpy Martian soil now sits, finally, within the TEGA “oven” on Phoenix, the room erupted with cheers and a standing ovation. Boynton then launched a rendition of “Shake, Shake, Shake” he had cued-up on his laptop, and started dancing. If that mental image doesn’t make it clear, getting the soil into TEGA is big, and the entire Phoenix team is excited about the accomplishment. Boynton, who leads the investigations with the Thermal and Evolved Gas Analyzer instrument, and his team have been trying various methods for several days to get the stubborn soil through a screen and into TEGA. The instrument will heat the soil and analyze the gases released to check for water vapor and other chemicals in the soil.

Commands to vibrate the screen were sent to Phoenix for three separate days. Boynton said that the oven might have filled because of the cumulative effects of all the vibrating, or because of changes in the soil’s cohesiveness as it sat for days on the top of the screen.

“There’s something very unusual about this soil, from a place on Mars we’ve never been before,” said Phoenix Principal Investigator Peter Smith. “We’re interested in learning what sort of chemical and mineral activity has caused the particles to clump and stick together.”

Between the shaking and the other new technique developed with the robotic arm called “sprinkling,” Smith hopes they won’t encounter future problems with getting the soil where they want it to go. “Delivering the soil is something we’re getting better at everyday,” he added.

Tomorrow, Thursday June 12, commands will be sent for the TEGA to heat the soil. Initial results may be available on Friday.

“We’ll do a low temperature bake that will tell us how much ice is in the soil,” said Boynton. ” We really don’t expect there to be much ice in the soil since it has been sitting out in the sun and vibrated through the screen. It does look like the soil has changed.”

TEGA has eight ovens to “bake” soil samples. Once an oven is used, it can’t be emptied and used again, so Phoenix has just eight chances to analyze the soil.

While there’s been some debate about the characteristics of Martian arctic soil, Smith said most researchers on the Phoenix team believe it’s a matter of when and not if Phoenix will definitely prove there is water ice region the lander sits on. “There are very few people who don’t believe there’s ice under the soil,” he said. “There also could be a crusty layer of salt on top because of evaporation.”

“We all have a lot of confidence we’ll get down to the ice,” Boynton added. “We may have exposed some in the act of landing. The MECA instrument will help the debate on salt. In a week or two we hope to get enough data to address these speculations.”

MECA is the Microscopy, Electrochemistry, and Conductivity Analyzer, which contains four single wet chemistry labs that will dissolve small amounts of soil in water, to determine the pH and what minerals are in the soil. Those tests will be done later in the mission.

Plans for today’s activities for Phoenix include sprinkling Martian soil on the delivery port for the spacecraft’s Optical Microscope and taking additional photos for a high-resolution color panorama of the lander’s surroundings.

Original News Sources: Phoenix press conference, Phoenix press release