Successful New Landing on Mars

Those white scrape areas are intriguing. Can the lander re-scrape there and dig a little deeper? If it were ice, wouldn't it be dirty ice instead of white?

Looks like Mars may be made of marshmallow under the topsoil. Or styrofoam. Maybe we landed on an ancient Martian landfill.

I don't know if there are any plans to "re-scrape" the same locations or not. They do plan to dig deeper, but I haven't read anything about them doing it in the same scraped areas.

The first priority is probably to get the requisite number of samples from various locations into the ovens.

After the planned mission is complete (whatever that is), if this lander keeps working as long as the rovers are, maybe they'll just start using the shovel arm to scrape topsoil all around the lander and take pictures over and over again.

Spirit and Opportunity are running so long they're probably having trouble figuring out what to do with them.

By Alan Boyle
Science editor
MSNBC
updated 8:26 p.m. CT, Thurs., June. 19, 2008

The scientists behind NASA's Phoenix Mars Lander mission now know that they had their first close-up look at Martian ice ?- because it has vanished from the picture.

Days ago, streaks and bits of whitish material were spotted at the bottom of a trench dug by the lander's robotic scoop, leading scientists to speculate that the stuff was either ice or salt. An initial chemical analysis was inconclusive, but scientists said they could tell by seeing if the material disappeared after exposure to the thin Martian atmosphere.

Under such conditions, water ice would turn directly into vapor rather than melting into liquid, in a process known as sublimation. When scientists compared Sunday's pictures with imagery captured early Thursday, dice-sized crumbs of the white material were clearly missing.

"It must be ice," the University of Arizona's Peter Smith, principal investigator for the Phoenix mission, said Thursday in a NASA status report. "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."

A larger vein of white material is still visible in the trench, which scientists have dubbed "Dodo-Goldilocks."

Could it be dry-ice and not water-ice?

If it turns to vapor, how will they ever know its composition?

Maybe part of it was scooped up when they made the scrape, and made its way into the oven for analysis?

Oh, yeah. The oven would be air tight, likely. Another great mystery solved.

I still say maybe it was marshmallow, and was licked up by the Martian lifeforms when NASA wasn't looking.

Amy Winehouse saw it, thought it was cocain, and snorted it all the way through space.

Fancy arresting Amy. How low-life can they get?

And now Naomi has got 200 hours community service for assaulting two police officers with her handbag.

She should have got an MBE for not using her hat-pin.

The Wired Science blog has been flooded with comments and questions about yesterday's announcement that the Mars Phoenix Lander has observed ice on Mars. Some of these questions are so good that we can't let them go unanswered. So here's our Mars Ice FAQ. If you've got more questions, put them in the comments below!

How do you know it's water ice, not CO2 ice (aka 'dry ice')?

There is a lot of CO2 ice on Mars in the winter. However, Phoenix landed in the Martian arctic during the summer (because the lander is solar powered, the extra summer light is a necessity). In the Martian summer it is much too hot for dry ice to be solid. It would be like trying to keep water ice from melting on a 140-degree day here on Earth.

Carbon dioxide (CO2) will freeze on Mars at -125 C. Today's weather report from the Canadian weather station on Phoenix shows a low of -80 C -- way too hot for dry ice to stay solid right now. (Note the largest "pebbles" of ice were seen to stay solid for a day before disappearing).

Why not send instruments to detect life?

If you are going to make a claim like, "I have found life on Mars," you have to be prepared to show that there is NO chance your sample was contaminated with Earth bacteria before launch. To do that takes an incredible amount of sterilization. Don't worry -- they have already done a lot of sterilizing on the Mars Phoenix before launching it. But to really be sure they would have to go to extreme measures to be able to rule out any contamination, and doing that would have drastically increased the cost of the mission beyond its budget. So NASA and JPL plan missions that look for water and the conditions of life within the budgets they have now.

What about the bright white stuff in the sunshine?

The scientists said they are monitoring the bright patches in the sunshine for changes too. They are seeing some changes, but stay tuned for more explanation and details. As for how the "pebbles" that disappeared did so in the shade, one scientist did mention that the portion of the trench it was in was exposed to morning sunshine earlier in the day.

Why are the pictures not all in color?

Be patient. The first images sent out are the raw files from the lander. The science team is committed to getting us the images to us fresh off the presses, so they send out the raw (monochrome) images first. Typically if you wait a day, the team will release the image in full color once it has been processed (see above for full color version of yesterday's image).

How can water ice go straight from being a solid to being a gas (sublimation)?

Just like dry ice does here on Earth, water ice goes from solid to gas when the pressure is below 6.1 millibars and it gets heated (like it does in the Martian sun). It can also go straight from solid to gas above 6.1 millibars when the vapor pressure (amount of water vapor in the air) is low enough. This is because the molecules of water in solid form and gas form are not at equilibrium.

You might be surprised to know that the same thing happens here on Earth. If you have a frost-free freezer, you may have noticed that your ice cubes gradually shrink over a period of days. This is sublimation: the fan is constantly sucking water vapor out of the freezer so the ice cubes surrender more and more water molecules to the dry air over time.

The pressure on Mars is about 8 millibars, very close to the "triple point" of water, which is the point where it can easily exist as either a solid, a liquid or a gas (see the chart below). Since the vapor pressure is so low, water can easily sublime in the Martian atmosphere, especially as the surface heats up in the sunshine. When that happens, the soil can often get hotter than the air in the sunshine (think of a lizard sunbathing on a hot rock).



You can get a list of the daily weather reports from Mars on the Canadian Space Agency's webpage. It includes the temperature, pressure and visibility at the landing site.

Phoenix ice photos
Compare these two close-up pictures taken on sol 20 (left) and sol 24 of a trench dug in the Martian surface by NASA's Phoenix Lander. Those sols of the Phoenix Mission (a sol is a Martian day), correspond to June 15 and 18 on planet Earth. Light-colored, dice-sized chunks, visible in the lower left shadow region of the trench in the sol 20 image have vanished by sol 24 -- a strong indication that the chunks were ice uncovered by digging the shallow trench. The vanishing act likely demonstrates the sublimation of ice in the trench, a process similar to evaporation, in which the ice went directly from solid to gas after it was exposed to sunlight and the thin, dry Martian atmosphere.

http://www.nasa.gov/mission_pages/phoenix/images/press/sol_020_024_change_dodo_v3.html

BBB - that is interesting.

Re: Phoenix ice photos

I wonder why the exposed white patches didn't go away (sublimate)?

Why would small chunks of dirty material (which, if they are ice, one would assume broke off from the white patches) sublimate away, but in the same amount of time, the white patches seem unchanged?

I wish NASA would do a better job of explaining their conclusions.

one was ice, one was mineral?

Can the Martian arctic support extreme life?
By ALICIA CHANG - 8 hours ago

LOS ANGELES (AP) ?- Bizarre microbes flourish in the most punishing environments on Earth from the bone-dry Atacama Desert in Chile to the boiling hot springs of Yellowstone National Park to the sunless sea bottom vents in the Pacific.

Could such exotic life emerge in the frigid arctic plains of Mars?

NASA's Phoenix spacecraft could soon find out. Since plopping down near the Martian north pole a month ago, the three-legged lander has been busy poking its long arm into the sticky soil and collecting scoopfuls to bake in a test oven and peer at under a microscope.

There hasn't been a eureka moment yet. But Phoenix turned up a promising lead last week when it uncovered what scientists believe are ice flecks in one trench and an icy layer in another.

Scientists hope experiments by the lander will reveal whether the ice has ever melted and whether there are any organic, or carbon-containing, compounds.

"We're looking for the basic ingredients that would allow life to prosper in this environment," chief scientist Peter Smith of the University of Arizona in Tucson has said in describing the mission's goal.

The discovery of extreme life forms, known as extremophiles, in unexpected nooks and crannies of the Earth in recent years has helped inform scientists in their search for extraterrestrial life.

"It's very suggestive that there are lots of worlds that may support life that at first glance may look like fourth-rate real estate," said Seth Shostak, an astronomer at the SETI Institute, a nonprofit dedicated to the search for extraterrestrial intelligence.

While the possibility for ET seems to grow with new extremophile discoveries on Earth, the truth is there's no evidence that life ever evolved on Mars or if it even exists today.

But if there were past or present life on the red planet ?- a big if ?- scientists speculate it would likely be similar to some extreme life on Earth ?- microscopic and hardy, capable of withstanding colder-than-Antarctica temperatures and low pressures.

"It's going to be microbes. It's not going to be a little green man," said Kenneth Stedman, a biologist with the Center for Life in Extreme Environments at Portland State University.

Under a microscope, extremophiles vary in size and shape. Some resemble miniature corkscrews while others are rods or irregular shapes. Scientists use a dye to distinguish the living ones from the dead.

The Phoenix mission has its limitations beside a shoestring budget of $420 million. It doesn't carry instruments capable of identifying fossils or living things. Rather, the lander has a set of ovens and a gas analyzer that will heat soil and ice and sniff the resulting vapors for life-friendly elements. Its wet chemistry lab will test the pH, or acidity, of the soil much like a gardener would. And its microscope will examine soil granules for minerals that may indicate past presence of water.

Most living things on Earth thrive not only in the presence of water, but also need sunlight, oxygen and organic carbon. But the range of conditions in which life can survive has been expanded with recent discoveries of micro-organisms trapped in glaciers and rocks or living in volcanic vents and battery acid-like lakes.

These extreme conditions on Earth mirror the harsh environments found on Mars and other parts of the solar system. Present day Mars is like a desert with no hint of water on its weathered surface, although studies of rocks suggest the planet was wetter once upon a time.

Most researchers agree life likely cannot develop on the Martian surface, which is bombarded by lethal doses of radiation. But satellite images have revealed a softer side, spying hints of a vast underground store of ice near the red planet's polar regions. Phoenix last week hit what's thought to be an ice layer 2 inches below the surface.

Even if Phoenix uncovers microbe-habitable conditions, a more sophisticated spacecraft would be needed to determine if life was ever there or is present now.

The last time NASA looked for organics was during the 1976 twin Viking missions, which sampled soil near the Martian equator but turned up empty.

Scientists chose to dig in Mars' far north this time because they think it's an analog to Earth's polar regions, which preserve life's building blocks and sometimes even life itself in ice.

Researchers have shown microbes on Earth can be inactive in a deep freeze for thousands of years and resuscitated under the right conditions.

In 2005, NASA researchers announced they revived bacteria that were apparently dormant for 32,000 years in a frozen pond in central Alaska. Earlier this month, Penn State University scientists said they were able to grow in the lab an ultra-small species of bacteria trapped in a Greenland glacier under high pressure and low oxygen for at least 120,000 years.

"There's a lot of amazing things that survive in the cold environments," said Jennifer Loveland-Curtze, a senior research associate at Penn State.

What that means for Mars and other hostile environments is debatable. But scientists are plumbing the depths of Earth for clues to possible life that may exist elsewhere in the universe.

"We need to continue to try to understand what's going on with the extremophiles here on Earth," said Stedman of Portland State University. "The more we learn how extremophiles here are functioning, the more that will inform any kind of future mission."

By KENNETH CHANG
New York Times

The lopsided shape of Mars may well be a result of a cataclysmic impact of a Pluto-size meteor billions of years ago, three teams of scientists are reporting. That would suggest that the lowlands of Mars's northern hemisphere are a single gigantic impact crater ?- the largest crater in the solar system.

"The early solar system was a pretty exciting place," said Francis Nimmo, an associate professor of earth and planetary sciences at the University of California, Santa Cruz, and the lead author of one of three scientific papers to appear in Thursday's issue of Nature. "There were big collisions happening fairly frequently, and those collisions affected what the planets ultimately ended up looking like."

About the same time, more than 4 billion years ago, Earth is believed to have been hit by a Mars-size object, which created the moon, and signs of a giant impact have also been detected on Mercury.

NASA's Viking orbiters observed in the 1970s that the bottom two-thirds of Mars was about two miles higher in altitude than its top third. Since then, planetary scientists have bandied about two hypotheses to explain the dichotomy: either some strangeness with the internal dynamics of Mars generated a thicker planetary crust in the south, or the northern surface was stripped away by a megameteor impact.

The impact idea, first proposed in the 1980s by Steven W. Squyres, now an astronomy professor at Cornell, and Don Wilhelms of the U.S. Geological Survey, ran into several objections. The boundary between lowlands and highlands does not have a simple round shape like most craters, there is no crater rim, and an impact that large should have, in theory, melted the entire surface. Then, when the rocks hardened again, the planet should have returned to the shape of a sphere, which is what occurred after the impact that created the Earth's moon.

The three Nature papers "have removed significant objections to the impact model," said Walter S. Kiefer, a staff scientist at the Lunar and Planetary Institute in Houston, who wrote an accompanying commentary in Nature.

Squyres said the new findings did not prove that his idea was right, but "they've really gone and made some new observations, which make a strong case that the idea really makes sense."

In the first paper, scientists at MIT and NASA's Jet Propulsion Laboratory took a closer look at the boundary, using topographical measurements by NASA's Mars Global Surveyor orbiter and gravity measurements from the Mars Odyssey. About a third of the boundary is obscured by lava that flowed out of Tharsis, the largest volcano in the solar system. The topographic and gravity measurements enabled the scientists to peer at the geological structures below Tharsis.

"What we found, very surprisingly, is that the dichotomy boundary is very well matched by an ellipse on the surface of Mars," said Jeffrey C. Andrews-Hanna, a postdoctoral researcher at MIT and the lead author of the first Nature paper. "That was kind of the smoking gun for us."

The ellipse, the scientists said, measures 6,500 miles by 5,300 miles.

Independently, two other teams of scientists performed computer simulations that indicate a meteor impact could plausibly create a crater of that size and shape. The two-dimensional simulations, performed by Nimmo and his collaborators at Santa Cruz and the University of London, show that "the crust basically gets stripped off half the planet," Nimmo said. "You can watch the cavity it carved out wobble up and down and eventually come back to equilibrium."

Simulations by scientists at Santa Cruz and the California Institute of Technology performed similar calculations, but in three-dimensions. Those calculations could only track the layer of crust coarsely, but could investigate impacts that struck at an angle; they found that a 30- to 60-degree angle produced elliptical-shaped craters and again showed that the impact would not have melted the entire Martian surface.

Oded Aharonson, an associate professor of geological and planetary sciences at Caltech and an author of the paper describing the three-dimensional model, said the impact would have released the energy of 75 trillion to 150 trillion megatons of TNT. To release that much energy, a meteor 1,250 miles wide ?- almost as large as Pluto ?- would have slammed into Mars at some 20,000 miles per hour.

None of the research disproves the alternate hypothesis that Mars's internal dynamics produced the dichotomy, although it is unclear how such a process would generate an elliptical crater. Answering the question more conclusively will require more data from Mars.

Scientists Find Water Vapor, Key Nutrients in Mars Soil

By KENNETH CHANG
Published: June 27, 2008
Stick an asparagus plant in a pot full of Martian soil, and the asparagus might grow happily, scientists announced Thursday.

An experiment on NASA's Phoenix Mars lander shows the dirt on the planet's northern arctic plains to be alkaline, though not fiercely alkaline, and full of the mineral nutrients that a plant would need.

"We basically have found what appears to be the requirements, the nutrients, to support life whether past, present or future," Samuel P. Kounaves of Tufts University, who is leading the chemical analysis, said during a telephone news conference on Thursday. "The sort of soil you have there is the type of soil you'd probably have in your back yard. ."

Mars today is cold and dry, and the surface is bombarded by ultraviolet radiation, making life unlikely, but conditions could have been more habitable in the past. Thus, plants that like alkaline soil ?- like asparagus ?- might readily grow in the Martian soil, provided that other components of an Earthlike environment like air and water were also present.

The preliminary findings from Phoenix do not answer whether life ever existed on Mars (or might still exist somewhere underground), only that conditions, at least at this location, are not the harshest imaginable. The soil, taken close to the surface, was similar to what is found in parts of Antarctica, Dr. Kounaves said. The soil elsewhere on the planet could well be very different; even the soil farther down in the ground could turn out acidic or otherwise vary in composition.

The Phoenix is capable of performing the same chemical analysis on three more samples.

In a different experiment, a tiny oven heated another sample of the Martian soil to 1,800 degrees Fahrenheit, which released water vapor. "This soil clearly has interacted with water in the past," said William V. Boynton of the University of Arizona, the lead scientist in this experiment.

Dr. Boynton said he could not say when the liquid water was present or even where it was. The moisture might have come from dust particles that had blown there from other parts of Mars. "At this point, it is difficult to quantify what was given off," he said.

The oven experiment also found carbon dioxide vapors, not surprising since Mars' thin atmosphere is primarily carbon dioxide. The data has not yet revealed any carbon-based compounds.

The Phoenix's mission is not directly looking for life on Mars, but rather whether conditions for habitability ever existed. In the wet chemistry experiment, water was mixed into the soil to produce Martian mud. Then the apparatus performed same sorts of tests that gardeners use to test the condition of their soil.

The pH level was between 8 and 9, Dr. Kounaves said. The pH, or potential of hydrogen, reflects the concentration of hydrogen ions, or acidity, of a substance and usually varies between 0 and 14, with 7 considered neutral. (The water of Earth's oceans, for comparison, has a pH of 8.2.) The experiment also found the presence of magnesium, sodium, potassium and chloride ions in the soil.

"There's nothing about it that would preclude life," Dr. Kounaves said. "In fact, it seems very friendly."

They have overwhelming evidence that Mars used to be inhabited, megalithic structures, pyramids, villages and other inhabited places, ancient mechanical debris strewn across the sand, and NASA, which can't deal with the implications of all that to several of their basic theories, wants to land probes on the poles and look for water or microbes...