Category: Missions

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NASA’s Phoenix Mars Lander has a fork-like conductivity probe on it’s robotic arm, and results from the instrument are presenting a bit of a quandary for mission scientists. The thermal and electroconductivity probe has sensed humidity rising and falling in the air the near the lander, but when stuck into the ground, its measurements so far indicate soil that is thoroughly and perplexingly dry. “If you have water vapor in the air, every surface exposed to that air will have water molecules adhere to it that are somewhat mobile, even at temperatures well below freezing,” said Aaron Zent, lead scientist for the probe. While Phoenix has other tools to find clues about whether water ice at the site has melted in the past, the conductivity probe is the main tool for checking for present-day soil moisture.

Preliminary results from the latest insertion of the probe’s four needles into the ground, on Wednesday and Thursday, match results from the three similar insertions in the three months since landing. “All the measurements we’ve made so far are consistent with extremely dry soil,” Zent said. “There are no indications of thin films of moisture, and this is puzzling.”

In below-freezing permafrost terrains on Earth, that thin layer of unfrozen water molecules on soil particles can grow thick enough to support microbial life. One goal for building the conductivity probe and sending it to Mars has been to see whether the permafrost terrain of the Martian arctic has detectable thin films of unfrozen water on soil particles. By gauging how electricity moves through the soil from one prong to another, the probe can detect films of water barely more than one molecule thick.

Three other sets of observations by Phoenix, in addition to the terrestrial permafrost analogy, give reasons for expecting to find thin-film moisture in the soil.

One is the conductivity probe’s own measurements of relative humidity when the probe is held up in the air. “The relative humidity transitions from near zero to near 100 percent with every day-night cycle, which suggests there’s a lot of moisture moving in and out of the soil,” Zent said.

Another is Phoenix’s confirmation of a hard layer containing water-ice about 5 centimeters (2 inches) or so beneath the surface.

Also, handling the site’s soil with the scoop on Phoenix’s robotic arm and observing the disturbed soil show that it has clumping cohesiveness when first scooped up and that this cohesiveness decreases after the scooped soil sits exposed to air for a day or two. One possible explanation for those observations could be thin-film moisture in the ground.

The Phoenix team is laying plans for a variation on the experiment of inserting the conductivity probe into the soil. The four successful insertions so far have all been into an undisturbed soil surface. The planned variation is to scoop away some soil first, so the inserted needles will reach closer to the subsurface ice layer.

“There should be some amount of unfrozen water attached to the surface of soil particles above the ice,” Zent said. “It may be too little to detect, but we haven’t finished looking yet.”

Source: Phoenix News

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So, what do you do on a holiday? It’s Labor Day here in the U.S., and the Phoenix lander on Mars is just watching the clouds go by across the Martian sky. This movie clip consists of 10 frames taken over a 10 minutes period by the Surface Stereo Imager on the lander. The images were actually taken on Sol 94 (August 29 here on Earth) at 2:52 to 3:02 local time at the Phoenix landing site on Mars northern polar region. Scientists say particles of water-ice make up these clouds, like ice-crystal cirrus clouds on Earth. Ice hazes have been common at the Phoenix site in recent days. But, of course, Phoenix is still hard at work on Mars, and recent images downloaded from the lander show the doors have been opened on another tiny oven on the TEGA (Thermal and Evolved Gas Analyzer), oven #1, to bake another soil sample. Other images of the scoop on the robotic arm shows soil inside on one image, and on a subsequent image, it looks as though the scoop has dumped the sample, perhaps inside the oven, or it may have been a test scoop and dumped out on the ground.

The camera took the cloud images as part of a campaign by the Phoenix team to see clouds and track winds. The view is toward slightly west of due south, so the clouds are moving westward or west-northwestward.

The clouds are a dramatic visualization of the Martian water cycle. The water vapor comes off the north pole during the peak of summer. The northern-Mars summer has just passed its peak water-vapor abundance at the Phoenix site. The atmospheric water is available to form into clouds, fog and frost, such as the lander has been observing recently.

And here are the images from Sol 96 showing the open oven and the scoop with a sample of soil inside.

Oven door #1 has been opened.

Scoop with soil inside, and then dumped.

Images are from Sol 96, or August 31, 2008.

Source: Phoenix News site and Gallery

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NASA’s Mars Exploration Rover Opportunity has successfully climbed out of the Victoria Crater. “The rover is back on flat ground,” said an engineer who drives it, Paolo Bellutta of JPL. Opportunity used the same path to exit the crater and was used to enter the crater almost a year ago. “We’re headed to the next adventure out on the plains of Meridiani,” said JPL’s John Callas, project manager for Opportunity and its twin rover, Spirit. See more images from Opportunity’s climb….

Opportunity used its own entry tracks from nearly a year ago as the path for a drive of 6.8 meters (22 feet) bringing the rover out over the top of the inner slope and through a sand ripple at the lip of Victoria Crater. The exit drive, conducted late Thursday, completed a series of drives covering 50 meters (164 feet) since the rover team decided about a month ago that it had completed its scientific investigations inside the crater.

Here, Opportunity is back where she was almost a year ago before heading into the crater. Look closely and try to figure out which tracks are new and which are from a year ago!

Opportunity stretches her robotic arm after leaving Victoria crater. See the crater in the background with the “Cape Verde” area (prominent ledge) visible. The crater spans about 800 meters (half a mile) in diameter and reveals rock layers that hold clues to environmental conditions of the area through an extended period when the rocks were formed and altered. The sun is behind this shot, creating shadows from the rover.

Now that Opportunity has finished exploring Victoria Crater and returned to the surrounding plain, the rover team plans to use tools on the robotic arm in coming months to examine an assortment of cobbles — rocks about fist-size and larger — that may have been thrown from impacts that dug craters too distant for Opportunity to reach.

Source: JPL Press Release,

Via Twitter, the Phoenix lander said, “I saw this beautiful sunrise yestersol. Bittersweet, as it means an end to midnight sun in the Martian arctic.” At Phoenix’s location above Mars arctic circle, the sun doesn’t set during the peak of summer in the northern hemisphere. If you recall, Phoenix took a montage of images of the non-setting sun last month.

But now, the period of maximum solar energy is past. On Sol 86, or the 86th Martian day after Phoenix landed, the sun set fully behind a slight rise to the north for about a half hour. This red-filter image taken by the lander’s Surface Stereo Imager, shows the sun rising on the morning of sol 90, Aug. 25, 2008, the last day of the Phoenix nominal mission.

The image was taken at 51 minutes past midnight local solar time during the slow sunrise that followed a 75 minute “night.” The skylight in the image is light scattered off atmospheric dust particles and ice crystals.

The folks over at Unmanned Spaceflight created a color poster of the sunrise in honor of Phoenix’s 90th sol on Mars:

Download your very own large or medium size poster.

Phoenix will continue working for another month on Mars, through September 30. It seems there’s many people out there hoping for another short mission extension — for as long as the carbon dioxide ice stays away!

Source: Phoenix News

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With the Phoenix lander busily working away on Mars and grabbing the recent headlines, we haven’t heard much from the other two robots on the Red Planet, the Mars Exploration Rovers, Spirit and Opportunity. Spirit has been hunkered down, trying to survive the harshest weeks of southern Martian winter. She’s waiting for the sun’s rays to get a little stronger before moving on, but has been taking images of her spot in the Home Plate area of Gusev Crater to create the panorama, shown here. Opportunity is now getting ready to head ’em up and move ’em out of Victoria Crater, where she’s been for nearly a year. So, what’s coming up for the two Energizer Bunny-like, long-lasting rovers?

“Both rovers show signs of aging, but they are both still capable of exciting exploration and scientific discovery,” said JPL’s John Callas, project manager for Spirit and Opportunity.

The team’s plan for future months is to drive Spirit south of Home Plate to an area where the rover last year found some bright, silica-rich soil. This could be possible evidence of effects of hot water.
Click here for an extra large version of Spirit’s panorama.

Opportunity will soon be on to new adventures.

“We’ve done everything we entered Victoria Crater to do and more,” said Bruce Banerdt, of NASA’s Jet Propulsion Laboratory in Pasadena, Calif. Banerdt is project scientist for the two rovers. Opportunity is heading back out to the Red Planet’s surrounding plains and check out some loose cobbles, or rocks that it drove by nearly a year ago before descending into the large Victoria crater to examine exposed ancient rock layers. But now that survey is complete.

Some of the cobbles that the rover will look at are approximately fist-size and larger. They were thrown long distances from impacts on Mars surface, and are interesting in that they might provide information about Mars’ subsurface varying areas.

“Our experience tells us there’s lots of diversity among the cobbles,” said Scott McLennan of the State University of New York, Stony Brook. McLennan is a long-term planning leader for the rover science team. “We want to get a better characterization of them. A statistical sampling from examining more of them will be important for understanding the geology of the area.”

Opportunity entered Victoria Crater on Sept. 11, 2007, after a year of scouting from the rim. Once inside, the rover drove close to the base of a cliff called “Cape Verde,” part of the crater rim, to capture detailed images of a stack of layers 6 meters (20 feet) tall. The information Opportunity has returned about the layers in Victoria suggest the sediments were deposited by wind and then altered by groundwater.

“The patterns broadly resemble what we saw at the smaller craters Opportunity explored earlier,” McLennan said. “By looking deeper into the layering, we are looking farther back in time.” The crater stretches approximately 800 meters (half a mile) in diameter and is deeper than any other seen by Opportunity.

Engineers are programming Opportunity to climb out of the crater at the same place it entered. A spike in electric current drawn by the rover’s left front wheel last month quickly settled discussions about whether to keep trying to edge even closer to the base of Cape Verde on a steep slope. The spike resembled one seen on Spirit when that rover lost the use of its right front wheel in 2006. Opportunity’s six wheels are all still working after 10 times more use than they were designed to perform, but the team took the spike in current as a reminder that one could quit.

“If Opportunity were driving with only five wheels, like Spirit, it probably would never get out of Victoria Crater,” said JPL’s Bill Nelson, a rover mission manager. “We also know from experience with Spirit that if Opportunity were to lose the use of a wheel after it is out on the level ground, mobility should not be a problem.”

Opportunity now drives with its robotic arm out of the stowed position. A shoulder motor has degraded over the years to the point where the rover team chose not to risk having it stop working while the arm is stowed on a hook. If the motor were to stop working with the arm unstowed, the arm would remain usable.

Source: JPL Press Release

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Scientists and engineers from NASA’s Phoenix Mars Lander continue with digging operations around the lander with the spacecraft’s robotic arm. They are looking for new materials to analyze and are examining the soil and ice subsurface structure. “We expect to use the robotic arm heavily over the next several weeks, delivering samples to our instruments and examining trench floors and walls to continue to search for evidence of lateral and vertical variations in soil and ice structures,” said Ray Arvidson, Phoenix’s “dig czar,” from Washington University in St. Louis. New trenches opened recently and shown in the image here include the “Burn Alive 3” trench in the eastern portion of the arm’s reachable workspace.

The team is excavating one side of this trench down to the ice layer and plans to leave about 1 centimeter (0.4 inch) of soil above the ice on the other side. From this intermediate depth is where scientists hope to test a sample of soil in Phoenix’s Thermal and Evolved Gas Analyzer (TEGA).

Near the western end of the arm’s workspace, the team plans to dig as deep as possible in the “Cupboard” excavation area to study properties of the soil and ice in one of the polygon trough areas. Like on Earth, the polygon patterns form in areas of permafrost that goes through cycles of swelling and shrinking as the ground thaws and refreezes.

A sample from the Cupboard area may be delivered to the lander’s wet chemistry lab, part of the Microscopy, Electrochemistry and Conductivity Analyzer (MECA) to test for the presence of salts. In addition, the robotic arm will try to acquire ice-rich soil from “Upper Cupboard” and observe the material in the arm’s scoop to determine whether the sample sublimates. Melting is an indication of the presence of salt. If the sample melts and leaves behind a salty deposit, “Upper Cupboard” would be the location for the next sample for the wet chemistry lab. If no salts are detected, the team would
continue with plans to use the “Stone Soup” trench for acquiring the next wet chemistry lab sample.

If you’re wondering about the interesting names of the different areas, the team names the areas and trenches to make identification easier (instead of saying something like “that trench in the upper left corner of the image taken on Sol 45.”) The names are chosen from various fairy tales and myths.

A change has taken place for the scientists and engineers working with Phoenix. They are now working on Earth time instead of Mars time. This eliminates the constantly transitioning work period as a Mars sol is about 40 minutes longer than an Earth day. Undoubtedly, this has to make their lives much easier, instead of juggling their Earth life and Mars work every day.

Daily activities are being planned for the spacecraft as the lander performs activities that were sent up the previous day. Digging and documenting are done on alternate days to allow the science team time to analyze data and adjust activities accordingly.

In upcoming sols, the team plans to scrape the “Snow White” trench and experiment with acquiring and holding samples in the shade versus the sun. They want to find out if prolonged exposure to sunlight causes the acquired material to stick to the scoop, as has occurred with previous samples.

Source: Phoenix News site

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More early morning frost is showing up on the Phoenix spacecraft. The Surface Stereo Imager (SSI) took several pictures of the “Telltale” on the Phoenix Mars Lander, the device used to measure wind velocities at the landing site on Mars and created a movie of bright specks of frost accumulating on the mirror of the Telltale. The movie was created from a series of images taken by the Surface Stereo Imager (SSI)between 12:54 a.m. and 2:34 a.m. during the 80th Martian day, or sol, of the mission (Aug. 15, 2008 here on Earth). Sorry, we couldn’t load the movie on this page, the file was too big. But follow this link to see it — the frost is very cool (pun intended).

Phoenix’s SSI took these images through a blue filter (450 nanometer wavelength) that is used primarily for viewing items on the spacecraft rather than the workspace or horizon. In order to increase the number of frames, the size of the individual images downlinked from the spacecraft has been reduced. These have been shown superimposed upon a full image of the telltale from Sol 13 for context. The frost on the mirror sparkles in low-angle light from the sun, which is barely above the horizon at this hour.

Via Twitter, the Phoenix spacecraft said not to worry, this type of early morning frost is not a concern for the operation of the spacecraft.
The Telltale experiment is a passive instrument that provides information about winds at the landing site. It consists of a lightweight Kapton tube hanging in Kevlar fibers that will deflect as a result of wind forces. Images of the Telltale obtained by the onboard camera (SSI) using long exposure times provide information on the deflection and dynamics that can be related to wind velocities and turbulence.

During the early-morning period when these images were taken the wind was blowing steadily at about 5 meters per second (about 11 miles per hour) from the northeast, as indicated by the telltale.

The telltale is about 10 centimeters (4 inches) tall and the total mass of the active part is about 10 mg. The experiment was built by the University of Aarhus, Denmark.

Here’s some info on the weather on Mars, although Sol 63 is the latest available from the Mars Weather Station on Phoenix. To learn more about the Weather Station, follow this link.

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It’s getting a little nippy at night on Mars. The Phoenix lander’s Surface Stereo Imager took this image at 6 a.m. on Sol 79 (August 14, 2008 here on Earth), and a thin layer of water frost is visible on the ground around the landing area. From subsequent images, the frost begins to disappear shortly after this image was taken as the sun rises on the Phoenix landing site.

The sun was about 22 degrees above the horizon when the image was taken, enhancing the detail of the polygons, troughs and rocks around the landing site.

This view is looking east southeast with the lander’s eastern solar panel visible in the bottom lefthand corner of the image. The rock in the foreground is informally named “Quadlings” and the rock near center is informally called “Winkies.”

This false color image has been enhanced to show color variations.

Earlier images taken in June, and put together here in sequence to form a movie, appears to show frost forming on Phoenix’s own legs.

But this isn’t the first time that frost has been imaged on Mars. The Viking lander took the picture below in 1979 of its landing site at Utopia Planetia showing ample amounts of frost on the surface.

In other news, the Phoenix lander also announced on Twitter that it has opened another TEGA oven door in preparation for receiving another sample of Martian soil to “bake and sniff.”

New Source: Phoenix Image Gallery, Wanderingspace.net