Phoenix PI Peter Smith can finally rest easy: There really is ice underneath the lander.

A followup to images from two days ago has found a smooth bright tabular substance that, to my wide eyes, can’t be anything other than solid H2O. You can see, at the top of the photo, the thruster nozzles that blew the soil away to reveal this ice.

“The consensus opinion is that we have found ice very close beneath the surface at our landing site,” Smith said today in a conference call. If you look at the image, you can see shadows from the lander legs that change angle right at the edge of ice, an indication that the ice sits below “four to six” inches of soil, according to Smith.

Today the lander is moving the robotic arm camera closer to the first patch of ice it found two days ago — an area that has been dubbed “Holy Cow”. Not a name that’s part of the Humpty Dumpty story, merely the first words out of Smith’s mouth. The robotic arm camera should be able to use its LED lights and get some color photos of this ice — good fodder for discussion in the coming days.

If you’re wondering why the University of Arizona’s Phoenix web page is down, Smith said that the Web site was hacked. “There was an amateurish attempt to delete some of our material,” he said, adding that it should be back up this afternoon.

Image: NASA/JPL/University of Arizona

Phoenix scientists may have taken their first glimpse of Martian ice. In order to see underneath the lander — an area likely blasted free of thin soil by the landing retrorockets — missions scientists had to use the camera on the end of the robotic arm. A picture returned last night shows a series of three tabular surfaces (upper middle in the image here). “They could be exposures of ice, or they could be exposures of rock,” said Ray Arvidson, of Washington University in St. Louis, Missouri, and lead for the robotic arm, at today’s press conference. “What we have is what you see.”

Today, the robotic arm camera was instructed to get closer to the surface in order to take color pictures.

The bad news today is that the TEGA instrument, which will bake soil and sniff for organic molecules, has a problem with its mass spectrometer. One of the filaments that ionizes the gas coming off the baked soil appears to have a short circuit, says the University of Arizona’s Bill Boynton, lead for the TEGA instrument. But he said that a second filament should still be able to do a decent job analysing samples, if the short circuit remains a problem.

Image: NASA/JPL/University of Arizona

Between my last post and this one, I’ve traveled on a plane from Tucson back to Washington, DC. My jet lag will be opposite to what the Phoenix scientists face. And my homecoming, unlike Peter Smith’s, means that I will be devoting less, not more, time to Phoenix. But my posts won’t stop, they’ll just be sluggish, as if I’ve got dust on my solar arrays.

I’m pleased that Nature sent me to cover the landing, but the magazine will be far more interested in the the scientific discoveries that are going to emerge. I’ve saved a few things to write for the magazine, so stay tuned!

The Mars Odyssey orbiter is going to be Phoenix’s twice-a-day radio link until engineers figure out what happened to the UHF radio on Mars Reconnaissance Orbiter, the Phoenix team announced this morning at a press conference here in Tucson. As I reported yesterday, MRO’s did come back on before the afternoon’s downlink, and so the Phoenix team was able to get some data down last night. But until they figure out what happened to MRO, Phoenix will use Odyssey. “This is a contingency that we have always planned for,” said JPL’s Barry Goldstein, Phoenix project manager. He said he had no worries about Odyssey being a much older spacecraft than MRO, noting that it was built the same time as Phoenix itself.

Also at the press conference, Mark Lemmon, Surface Stereo Imager lead, discussed what I tried to explain in my post this morning – how the SSI uses stereo vision to get depth perception, which allows for the determination of heights. He released a cool graphic of the digital elevation model that SSI has built up so far in the north workspace – the areas reachable by the robotic arm. Reds are low lying areas, the other colors are higher. So you can see that the arm has great access to a polygon directly in front.

“The red swath you see at the 10 and 11 o’clock postion is a trough between a polygon,” Lemmon said. "The yellows and greens and blues are the polygons themselves.”

The team has already started to divvy up the workspace. The area to the left of the robotic arm in the image is going to be used for digging and dumping. The high ground in yellow — nicknamed “Humpty Dumpty” — is going to be the start of a trench that will be dug from out to in, from the center of the polygon and across a trough. (Transects like this are really useful, as any geologist will tell you.)

Just to the right of Humpty Dumpty is a low trough area being called “Sleepy Hollow.” The arm will dig another trench there, but along the axis of the trough. Other areas have been preserved for the spiky electrical conductivity instrument. The robotic arm will have to dodge rocks that are already being given names such as “King’s Men” and “Headless.”

It will be fun to watch these names enter the Martian lexicon, as the stories that lie beneath these little patches of ground unfold.

Right now the activities of the Surface Stereo Imager, or SSI, seem a bit mundane — documentary pictures of the robotic arm, bland portraits of dust-free solar arrays — but make no mistake: The SSI is like an orchestra’s conductor, integral to the sweet scientific music that the Phoenix team hopes to make with the other instruments.

The key is that the SSI has two eyes, which give it depth perception. As it takes its panoramic shots, it is also building an elevation model. The model has already allowed mission scientists to spot several polygons, and has shown that one of the polygonal troughs sits within digging reach.

Knowing the precise 3-D terrain also will allow the robotic arm to move with confidence and efficiency. If the arm were to rely on its own single-eyed vision (there’s a camera just above the scoop), it would use shadows for depth perception and move slowly and tentatively, wary of ramming into something.

“The arm is kind of dumb,” says Phoenix PI Peter Smith. “It has to be told where to go.” Adds Mark Lemmon, lead scientist for the SSI: “It lets us know our coordinates easily rather than painfully.”

But the SSI won’t be totally left out of the science. It’s already taking daily pictures of the telltale on the weather mast to gauge windspeeds. And Lemmon told me about two other exciting long-term experiments.

One will involve watching ice melt sublime. After using the scoop to dig a double-wide trench, a swath of ice will be exposed to the summer sun. The SSI will sit back and watch the surface recede until it reaches equilibrium. Knowing the precise shape of the ice surface over time (as well as temperatures and amount of sunshine) will allow the team to back out key parameters for the ice that have long been assumed in modeling the way ice grows and recedes on Mars.

A second experiment would recycle the “trash” of other experiments. As the scoop excavates, it needs to dump dirt somewhere. Some scientists would make these middens useful. They want to build a big dirt pile (using the cone-like shape of the pile to learn something about the size distribution of the soil particles) . Then, every day, the SSI would take a picture of the pile, watching it change in size and shape as the wind does it work — it would thus constrain models for the wind-driven processes on Mars.

Image: University of Arizona

In the toilets at the Science Operations Center, there are bags containing vials and plastic jugs. A sign above the bags warns: “Do not throw these away!”

It is part of an experiment within an experiment. Phoenix scientists are going to sample Mars’ ice; Walter Sipes is going to sample the Phoenix scientists’ urine — as a way of assessing their body clocks.

Sipes, a NASA psychologist at Johnson Space Center in Houston, Texas, usually works with astronauts on the International Space Station, helping them adjust their body clocks when they suddenly need to perform a maneuver on, say, Moscow time.

Now he’ll help the Phoenix scientists adjust to Mars time. They work through the night to have fresh instructions ready to relay to Phoenix before it starts its day. As deputy project scientist Deborah Bass puts it: “We do the Martian night shift. The lander works the day shift. It has it easy in that respect.”

Since the the Martian day is longer than Earth’s by almost 40 minutes, the scientists have to come in a little later each day. The effect on their bodies is as if they are continually flying west across time zones, says Sipes.

Twenty scientists were recruited for the experiment. They will be given light boxes to put by their computer workstations. At specific times of the day, they are dosed with solid blue light which helps reset body clocks by triggering the production of melatonin.

Every four hours, the scientists are expected to collect some urine. Sipes and his colleagues will look for melatonin spikes. If the spikes shift along with Mars time, he’ll know that the scientists are following his strict sleep and light regimen.

A final part of the experiment is to see if the effort is worthwhile. Every day, at the beginning and end of their shifts, the test subjects will take cognitive tests. Sipes says he didn’t have enough money to do a control group. But he’ll still be able to look for differences in cognitive test results between diligent subjects and the slackers who avoid the body clock regimen. He’ll know who is being good and who is being naughty because the subjects wear special wristwatches that are sensitive to both motion and light; Sipes can thus tell if the scientists are in the dark and motionless (and, presumably, sleeping).

Bass hopes that the team will take Mars times somewhat seriously: “In the beginning you run on adrenaline. But you need to protect people from themselves.”

Just a quick update: The Mars Reconnaissance Orbiter UHF radio is back on, and so the orbiter should be back in business as the go-to relay station for Phoenix. Mission scientists said that when the radio was turned back on this afternoon, it didn’t “safe” itself and turn off immediately, as it did this morning just before it was supposed to upload Phoenix’s chores for the day. MRO should be back in business for the afternoon’s downlink that’s supposed to be happening right now.

That means that the day isn’t completely wasted. Even though Phoenix didn’t have a complete set of instructions to perform today, it did have some back-up tasks it performed. So the scientists hope to have some new stuff: a full color image to the north, from the edge of the lander’s workspace to the horizon, and also some weather data.

Later update: Missions scientists have confirmed that they were able to get some “great looking” pictures down today via MRO, and it looks like they are already up, posted here. Peter Smith should have something he can talk about at tomorrow’s press conference (as long as HiRise doesn’t steal the show again).

The big (and first bad) news coming out of the press conference this morning is that the UHF radio link on Mars Reconnaissance Orbiter was shut down before it sent Phoenix its workday instructions for sol two on Mars. That means that all of the lander’s planned activities for today — tentative first motions of the robotic arm, the filling in of panoramic blank spots – will be delayed by a day.

Jet Propulsion Lab managers seemed confident it was just a temporary set back. JPL Mars Exploration Program manager Fuk Li said the radio shut down was triggered by a “transient event,” perhaps something like a blast of cosmic ray particles. In those situations, MRO pre-emptively shuts the instrument down as a safety precaution. Engineers are trying to turn it back on right now.

If the problem persists, mission managers can switch to the UHF radio on Mars Odyssey (which is going to be used for half of the uplinks and downlinks anyway). There’s also a backup UHF radio on MRO.

But this is still a minor setback right when the scientists wanted to charge out of the gate. Li said MRO had turned on its radio roughly 100 times for practice without experiencing any problems. Ed Sedivy, Phoenix program manager at Lockheed Martin, said, “All this is is a one day hiccup for Peter,” he said.

Phoenix PI Peter Smith still had plenty to be excited about in the first pictures, retrieved last night, of the workspace – the area within digging reach of the robotic arm. “There’s just a wonderful buffet of opportunities in front of us,” he said.

His team has spied a trough in one corner of the field of view, which he says is one of the depressions forming the boundary between the polygons that represent expansion and contraction cycles of the ice below. Smith wants to dig a trench across the trough next week, but first has to calibrate the robotic arm with practice motions and tentative first touches of the soil. There will be no digging in the troughs for now. “Those were designated National Parks last night,” Smith said.

By the way, among the pictures retrieved from the first sol on Mars were the first data from the weather station. The weather report: highs of -30 degrees Celsius, lows of -80 degrees, and winds gusting up to 20 kilometers per hour from the northeast.

The wind speeds were based on photos of the telltale, though they don’t know if the pictures they have reflect gusts or swirls. But Phoenix PI Peter Smith says he’s not worried about dust accumulating on the solar arrays. As with the Mars rovers, he will rely on periodic dust devils to sweep them free. “These dust devils are so efficient, we thought we’d use the same method,” he says.

And if you’re not happy with the weather wherever you are, you can remind yourself how good you’ve got it by downloading a daily Mars weather widget for your Mac. (I myself am going to miss the perfect 30 degree Celsius days here in Tucson.)

As amazing as the pic was of Phoenix in mid-descent, 20 seconds after its parachute deployed, the backdrop might be more specatcular. Alfred McEwen, PI for the HiRise camera on Mars Reconnaissance Orbiter, zoomed out to find Heimdall crater looming 20 kilometers in the background. “This really give you an idea of how small Phoenix is in relation to Mars,” he said at a press conference Tuesday morning here in Tucson.

The second picture shows another HiRise photo, 22 hours later, catching Phoenix sitting in its rock-less sea, with its solar arrays unfurled. Much of what Phoenix sits on is impact material ejected from Heimdall. McEwen doesn’t yet understand why bigger rocks are seen inside Heimdall, but so few are found by Phoenix. “Why that is is a mystery right now,” he says, adding that it’s possible that wind has deposited finer material since the Heimdall impact.

Images: NASA/JPL/University of Arizona