Marston's Share Discussion Threads

[ariane] 16/2/2007 07:15

Last Updated: Thursday, 15 February 2007, 19:01 GMT

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Rocks reveal Mars' watery past
By Jonathan Fildes
Science and technology reporter, BBC News, San Francisco



Water once flowed through fractures in layered rocks


Enlarge Image

Exquisite colour images of the Martian surface give a tantalising glimpse into the Red Planet's watery past.

Shots of the deep valley Candor Chasma show light coloured areas of rock where water could have flowed.

These "haloes" surround fractures in the Martian bedrock which provide a promising target in the search for evidence of past life on the planet.

The images, published in Science journal, were taken by a camera aboard Nasa's Mars Reconnaissance Orbiter.

"It lends support to the idea that a substantial body of groundwater existed on Mars in the past and may still persist to the present day," said Professor Stephen Clifford of the Lunar and Planetary Institute in Houston, Texas.

"The fact that there is such persuasive evidence of joints and fractures in the crust also suggests that this groundwater had the ability to flow enormous distances."

Huge rift

The High Resolution Imaging Science Experiment (HiRise) camera started its surveys in November 2006, eight months after Mars Reconnaissance Orbiter (MRO) entered orbit around the Red Planet.

It is best known for capturing stunning images of Nasa's robot explorers Spirit and Opportunity as they surveyed the planet from the ground.


Clay-like minerals are found in the Red Planet's Mawrth Vallis region


Enlarge Image

Nasa has recently admitted that some of the detectors on the camera are starting to fail.

The newly analysed images were taken last year. They show a snapshot of conditions in Candor Chasma, an area of the great Martian rift valley Valles Marineris.

This deep gash, the length of the United States, is up to seven times deeper than the Grand Canyon in places.

The images show a hilly landscape composed of alternating bands of light and dark coloured rock, suggesting the layers were deposited by regular cycles of water, wind or volcanic activity.

MARS RECONNAISSANCE ORBITER

Reached Mars in March 2006
Two-year primary mission
HiRise images are the clearest pictures of Mars
Two detectors on the camera have developed problems
Cutting across the striped scenery, the researchers identified a network of cracks, known as joints, surrounded by prominent haloes of bleached rock.

Writing in Science, the University of Arizona team said that similar features on Earth were "a clear indication of chemical interactions between fluids circulating within the fracture and the host rock."

Likely fluids include water, liquid carbon dioxide or a combination of the two, and may have flowed up from deep underground reservoirs.

Protected habitats

Previously, Europe's Mars Express mission had detected the signature of minerals altered by water in the Candor Chasma area.

The washed-out features, which have been "cemented" by minerals contained in the fluids, now stand proud from the valley walls.

They have been exposed by millions of years of erosion.

However, the fact that they were once underground has important implications for their ability to support life.

"The overlying areas of rock would have acted as a buffer against any harsh environmental conditions on Mars at that time," said Dr Chris Okubu of the University of Arizon and one of the authors on the paper.

"These areas would be nice protected areas for any biological processes to occur."


Erosion has uncovered rocks that were altered by the action of fluids


Enlarge Image

This is not the first time that scientists have found evidence of fluids upwelling from deep inside the Martian interior.

Last year, Nasa's Mars Global Surveyor (MGS) spacecraft spotted gullies and trenches thought to have been recently carved by outpourings of water or liquid carbon dioxide.

Other features, including dried-up lake beds, springs and river valleys, lend further weight to the theory that the planet was once awash with water and could therefore have supported life.

Nasa is examining all of these sites as possible targets for future ground based robotic missions.

However, the space agency says that if it has a chance of finding evidence of life on the planet, it must broaden its search.

"Following the water is a central aspect of exploration but the habitability issue also requires addressing the source of energy for life," said Dr David des Marais of the Nasa Ames Research Center.

Possible future targets include areas of the planet where the building blocks of life, such as carbon, can be found.

"We not only need to follow the water but we also need to follow the energy," said Dr des Marais.

The findings were presented at the American Association for the Advancement of Science (AAAS) annual meeting in San Francisco, US.

[ariane] 13/2/2007 06:58

Last Updated: Monday, 12 February 2007, 16:10 GMT



Red Planet 'hiking maps' produced

The topographic maps show an interesting region of Mars: Iani Chaos




Scientists using data from a European space probe orbiting Mars have produced new topographic maps of the Red Planet.
The "hiker's maps" provide detailed height contours and names of geological features on the Martian surface.

The European Space Agency (Esa), which compiled the maps, said it hoped the maps would become a standard reference for future research on the Red Planet.

The data, from the Mars Express spacecraft, has also been turned into 3-D models of the surface of Mars.

The topographic maps use contour lines to show the heights of the landscape.

The contour lines are superimposed upon high-resolution images of Mars, taken by the High-Resolution Stereo Camera (HRSC) aboard Mars Express.

The maps are much like those of Earth used by hikers and planning authorities.

The samples released by Esa show the Iani Chaos region of Mars because of its major topographical interest.

It is covered in individual blocks and hills that form a chaotic pattern across the landscape.

Mars Express entered orbit around the Red Planet in December 2003.

[e-boffin] 02/2/2007 10:46

Looking good. The share buy-back has obviously improved perceptions.

Surprised not generating more interest on the BB.

[energyi] 30/1/2007 06:48

Study: Surface of Mars Devoid of Life
\Ker Than
Staff Writer, SPACE.com
Mon Jan 29


The last refuge for Martian life, if it exists, might be deep below the planet's surface and beyond the reach of any currently planned missions, according to a new study.


After mapping cosmic radiation levels at various depths on Mars, researchers have concluded that any life within the first several yards of the planet's surface would be killed by lethal doses of cosmic radiation.


The finding will be detailed in the Jan. 30 issue of the journal Geophysical Research Letters.


Unlike Earth, Mars is no longer protected by a global magnetic field or thick atmosphere. As a result, the planet has been vulnerable to radiation from space for billions of years.


'Even the hardiest cells we know of could not possibly survive the cosmic radiation near the surface of Mars for that long,' said study leader Lewis Dartnell of University College London.


Dartnell and his team developed a radiation dose model that calculates how much solar and galactic radiation Mars is subjected to. They tested three surface soil scenarios and calculated particle energies and radiation doses on the surface and at various depths underground. From this, they calculated the length of time that the hardiest known cells on Earth could survive.


The team believes a good place to look for living cells on the red planet is in ice from a frozen sea recently discovered on Elysium Plantia, a major volcanic region on Mars. Scientists think the sea formed only within the last five million years.


'That's very, very recent,' Dartnell told SPACE.com. 'Five million years ago is yesterday in terms of geology.'


The researchers estimate that life could survive for long periods of time about 8 yards (7.5 meters) beneath Elysium's ice. However, this is still beyond the range of any currently planned missions.. The only mission that will come close, Dartnell said, is ExoMars, a European rover slated for launch in 2013. ExoMars will be equipped with a drill that can dig about 6.5 feet (2 meters) for samples.


Life in a crater


Other potential sites to dig for life are young craters, the researchers say. The exposed rock in craters is denser than the ice that covers much of the planet, and it provides better shielding against space radiation than ice. As a result, life might be able to survive closer to the surface. Another bonus of excavating in craters is that most of the vertical digging work would already be done.


'In effect, the meteorites dug tens of meters deep for you,' Dartnell said.


The researchers estimate that on a typical Martian exterior-one not covered in yards of ice or bombarded by meteorites-life might survive as close as 2 meters beneath the surface. While this is just within range of ExoMars' drill, the team's model also predicts that even Earth's toughest life forms would survive for a relatively brief amount of time-about 450,000 years-on Mars at those depths.


'After 450,000 years, our model says that only 1 in a million cells will survive,' Dartnell said in a telephone interview.


The cells wouldn't be killed so much by radiation as by an inability to repair themselves due to the frigid environment of Mars.


'If you had a beaker of water [filled with cells] and put it on the surface of Mars where radiation is highest, those cells would be perfectly happy,' Dartnell explained. 'There's actually less radiation on the surface of Mars than some natural locations on Earth."


The problem is that the subzero temperatures on Mars' surface makes it extremely difficult for cells to repair radiation damages that do occur or to divide. The cells would be frozen solid and held in stasis and the radiation damages would accumulate, until the point where they're killed off, Dartnell said.

Follow the water

Another good candidate for finding extant Martian life is new gullies recently discovered by Mars Global Surveyor, the researchers say. Evidence suggests the gullies might have flowed with water within the last five years, possibly ferrying underground cells to the surface.

The notion of life surviving deep underground is not unheard of. Subterranean microbes have been discovered two miles and deeper beneath Earth's surface. Furthermore, those bacteria used the planet's internal heat, in the form of radioactive elements like uranium and potassium to convert water molecules into useable energy.

'If you extend that to Mars,' Dartnell said, 'even if things are getting nuked off by radiation on the surface, if you dig deep enough, the internal heat of the planet might have melted down the permafrost ice into aquifers of liquid water where even today you could have an active ecosystem.'

Digging and Sniffing for Life on Mars
Rover Report Card: Prospect of Mars Life More Likely
Martian Life Could Have Evaded Detection by Viking Landers
Life On Mars: Swimming Right Under the Surface?
Bacteria Found Nearly 2 Miles Underground
Original Story: Study: Surface of Mars Devoid of Life


@:

[bullsvbears] 19/1/2007 11:44

Seems to have done for the SP!

[gbb483] 08/1/2007 15:05

Following the change of name and 4 for 1 stock split - a new thread!

[energyi] 30/10/2006 03:21

Life on Mars?
Very interesting article at WSJ Online on a new perspective regarding the possibility of life on Mars.

Here are the highlights (but don't be lazy, read the whole thing!):

In 1976, 2 Viking landers conducted 3 experiments searching for signs of life in the top few inches of Martian soil.
One test suggested biological activity, but was dismissed. Scientists assume that life requires organic (carbon-containing) molecules, and the experiments failed to find organic molecules in Martian soil.
Now, sophisticated instruments show that the Vikings couldn't have detected organic molecules even if any were present. Life-seeking experiments on future missions won't suffer from this flaw.

Current experiments show that life can exist in even the most extreme conditions. NASA experiments say that some microbes can survive and reproduce at 30°F, below freezing. "The lowest temperatures at which these organisms can thrive fall within the temperature range experienced on present-day Mars, and could permit survival and growth, particularly beneath Mars's surface," says astronomer Neill Reid of the Space Telescope Science Institute, Baltimore.

@:

[energyi] 09/1/2006 14:26

MIT Forum talks about things like:

Using caves to live on other planets:
Video date:
September 22, 2005
7:00 PM

"Revolutionary art and visionary physics are both investigations in the nature of reality. On the artist side, there's Picasso, a free thinker. Compare Picasso with Einstein. Each visualizes something before creating an equation or putting paintbrush to canvas."¡X Robert Cassanova

@:

[5miffy] 04/9/2005 21:19

I once met a rep form Mars.

[energyi] 04/9/2005 20:53

MARS Rovers in this video:

[rayrac] 29/8/2005 09:19

Very interesting thread. Thanks everyone!

[energyi] 29/8/2005 09:04

GALLERY: Wide-angle:

....
@:

[energyi] 29/8/2005 09:00

EVIDENCE OF ACTIVITY ON MARS... if not Life


@:

[energyi] 29/8/2005 08:58

Great series of programmes was made many months ago on BBC:
Programme Two: Fourth Rock from the Sun
Presented by Heather Couper

Heather Couper charts the ups and downs of the scientific exploration of Mars, since the launch of the first NASA probe in 1965. Mars was still an unknown world, and there were hopes that on its surface there would be vegetation, or mosses and lichens at the very least. There were even a few people clinging onto nineteenth century stories of canals on Mars. But the photographs Mariner 4 sent back to Earth didn¡¦t show canals, trees, or even moss. They showed a dry, dusty, crater-pocked desert, totally devoid of life. Our neighbouring planet had proved to be disappointingly inhospitable.

@:

[wild bill] 08/8/2005 16:07

Planet Mars

The Red Planet is about to be spectacular! This month and next, Earth is catching up with Mars in an encounter that will culminate in the closest approach between the two planets in recorded history. The next time Mars may come this close is in 2287. Due to the way Jupiter's gravity tugs on Mars and perturbs its orbit, astronomers can only be certain that Mars has not come this close to Earth in the last 5,000 years, but it may be as long as 60,000 years before it happens again.

This encounter will culminate on August 27th when Mars comes to within 34,649,589 miles of Earth and will be (next to the moon) the brightest object in the night sky. It will attain a magnitude of -2.9 and will appear 25.11 arc seconds wide. At a modest 75-power magnification.

Mars will look as large as the full moon to the naked eye. Mars will be easy to spot. At the beginning of August it will rise in the east at 10 PM and reach its azimuth at about 3 AM.

By the end of August when the two planets are closest, Mars will rise at nightfall and reach its highest point in the sky at 12:30 AM. That's pretty convenient to see something that no human being has seen in recorded history. So, mark your calendar at the beginning of August to see Mars grow progressively brighter and brighter throughout the month.

You might want to share this with most, if not all of your friends, your not friends, your children, and grandchildren. NO ONE ALIVE TODAY WILL EVER SEE THIS AGAIN.

[wild bill] 08/8/2005 16:06

Planet Mars

The Red Planet is about to be spectacular! This month and next, Earth is catching up with Mars in an encounter that will culminate in the closest approach between the two planets in recorded history. The next time Mars may come this close is in 2287. Due to the way Jupiter's gravity tugs on Mars and perturbs its orbit, astronomers can only be certain that Mars has not come this close to Earth in the last 5,000 years, but it may be as long as 60,000 years before it happens again.

This encounter will culminate on August 27th when Mars comes to within 34,649,589 miles of Earth and will be (next to the moon) the brightest object in the night sky. It will attain a magnitude of -2.9 and will appear 25.11 arc seconds wide. At a modest 75-power magnification.

Mars will look as large as the full moon to the naked eye. Mars will be easy to spot. At the beginning of August it will rise in the east at 10 PM and reach its azimuth at about 3 AM.

By the end of August when the two planets are closest, Mars will rise at nightfall and reach its highest point in the sky at 12:30 AM. That's pretty convenient to see something that no human being has seen in recorded history. So, mark your calendar at the beginning of August to see Mars grow progressively brighter and brighter throughout the month.

You might want to share this with most, if not all of your friends, your not friends, your children, and grandchildren. NO ONE ALIVE TODAY WILL EVER SEE THIS AGAIN.

[collection agency] 24/1/2004 22:52

Onlyme (or according to andre only...er....me I suppose)

Aye, saw it and ignored it, one ruined thread by Andre's madness is enough.

[onlyme] 24/1/2004 22:48

-- CA

He's back on the Moon, RED MOON, getit!
Intellectual, ha!

[the knowing] 24/1/2004 22:43

Brilliant !

[collection agency] 24/1/2004 22:41

Is that Andre's new office?

Looks like an intellectual desert to me....