The Mars rover Opportunity is making its way back out to the Martian plains nearly a year after descending into a large Martian crater, Victoria, to examine exposed ancient rock layers.

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“We’ve done everything we entered Victoria Crater to do and more,” said Bruce Banerdt, of NASA’s Jet Propulsion Laboratory in Pasadena, California who is project scientist for Opportunity and its rover twin, Spirit.

Opportunity is now preparing to look at loose cobble rock on the plains which are approximately fist-size and larger, which were thrown long distances when objects hitting Mars blew deep craters into the planet; even deeper than the recently explored Victoria crater.

“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 exploring from the rim. Once a drivable inner slope was identified, Opportunity used contact instruments on its robotic arm to inspect the composition and textures of accessible layers, then 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 20 feet tall. The information Opportunity has returned about the layers in Victoria suggest the sediments were deposited by wind and affected 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.” At approximately a half mile in diameter, it is the deepest seen by Opportunity.

Engineers are programming Opportunity to climb out of the crater at where it entered. A spike in electric current drawn by the rover’s left front wheel last month settled debate about whether to keep trying to get closer to the base of Cape Verde on the 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 of the pitfalls involved. Yet, unbelievably, the rover is still working well.

“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 drives with its robotic arm out of the stowed position because a shoulder motor has degraded over the years to the point where the rover team didn’t want 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; not a good thing.

“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.

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The picture below is a panorama mosaic taken by the Phoenix Mars Lander spacecraft on Mars showing the midnight sun over a period of several days.

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During eleven days, the path of the sun dropped lower over the northern horizon of Mars, captured by time-lapse images and composed into this mosaic. The arc in the picture is indicative of the polar nature of the Phoenix mission.

Phoenix has now been on Mars nearly 60 days. A set of imaging commands will soon be initiated to check a northwestern piece of the Martian horizon in early afternoon looking for dust devils, which are fairly prevalent on Mars. This will represent the first time Phoenix has systematically searched for dust devils. It appears to me that the resolution of the Phoenix camera is so good that any dust devils captured should make for very interesting photographs.

Image credit: NASA/JPL-Caltech/University of Arizona/Texas A&M University

So where did the water on Mars go? The water that made all these channels and gullies and so on and so forth. Sounds like there used to be quite a bit of it. There certainly isn’t an amount of ice at the poles that would account for all the water that has flowed on the planet. So what happened to it?

There has been a lot of press lately about evidence of water discovered on Mars. nearly every month this year something has developed in the gathering of water evidence on Mars for scientists to say it definitely existed.

This isn’t really a new story though. This link to NASA’s web site talks about the Mars Global Surveyor finding evidence of water on Mars. This was in June 2000. 

What’s good about this link is that it offers an explanation as to what happened to the water that once made these gullies on Mars.

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The atmospheric pressure at the surface of Mars is about 100 times less than it is at sea level on Earth. This lower pressure allows the liquid water to boil, violently and intensely. The gullies formed from the rapid outflow of water from the interior, creating these chasms before the water boiled off. The outflow of water and debris from inside Mars must have occurred repeatedly, over and over.

There is an oddity to the gullies. They are found in the coldest regions of Mars, not quite where one would expect to find them.

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The water on Mars is believed to be about a quarter of a mile below the surface. Certainly reachable by humans, as some mines are Earth reach down a mile underground. This means human explorers to Mars could access the water for drinking, for creating breathable air, and for extracting oxygen and hydrogen for energy.

Okay, so now I have another question. If the water boiled off, where did the hydrogen and oxygen go? Mars atmosphere is thinner than the atmosphere on Earth.

Oh well. One answer satisfies for now. I thought it was a very interesting answer too.

The robotic arm of the Phoenix Lander is scooping Martian soil that appears to be clumping together. This is not ideal for the tests the spacecraft is designed to perform on the soil.

Engineers are testing a revised method in light of the clumpy soil problem. The soil is intended to pass through a screen for the Thermal and Evolved-Gas Analyzer (TEGA) to test. After 20 minutes of vibrating the screen, only a few particles fell from the clumpy soil to pass through the screen.

The revised method will hold the scoop at an angle above the delivery target and attempt to sprinkle out a small sample through vibrating the scoop which is assisted by a motorized rasp on the bottom of the scoop.

Hopefully the tests will be able to go forward with this new method. I’d like to know why the soil is clumpy. It is wet clumpy or merely clay clumpy?

Phoenix mission 06.08.08

Next Sunday, May 25, at about 6:38 pm Central Time, the new Phoenix Mars Lander will land on Mars. Phoenix lander_Page_2

 

 

 

 

 

 

 

 

 

 

Phoenix is the first in NASA’s “Scout Program”. It is designed to study the history of water and search for complex organic molecules in the ice-rich soil of the Martian arctic.

Water has not been found on the surface of Mars, believed to be a cold desert planet; Phoenix will target the northern plains of the planet utilizing a robotic arm that can dig through the protective top soil layer to the water-ice below. Samples will be acquired for analysis.

Designed to be a low cost part of the overall Mars exploration mission, the goals of which are: (1) determine whether life ever arose on Mars; (2) characterize the climate of Mars; (3) characterize the geology of Mars; and, (4) prepare for eventual human landing and exploration.

Phoenix is a fitting name for this endeavor as it uses many components of two unsuccessful prior missions to Mars. In a sense then, the name like the mythical bird, denotes something that has risen from the ashes to be part of the Mars exploration effort.

Hopefully, there will be early pictures released soon after the landing that I can post. This mission is a nice follow up to the Spirit and Opportunity rover missions.

 

Channels Gullies Water ice

Channels, Nanedi Vallis

Water-ice, North Polar Cap

Gullies, Terra Sirenum