Марсианская Вечная Мерзлота имени РОНАТУ

[Salo]

http://www.spaceflightnow.com/news/n0902/08marscraters/

Geologic features in Martian craters shaped by water
PLANETARY SCIENCE INSTITUTE NEWS RELEASE
Posted: February 8, 2009

Scientists at the Tucson-based Planetary Science Institute (PSI) have found further evidence for the large role that water has likely played in shaping the Martian landscape.

Their results, which will be published in Icarus, provide strong evidence that multiple wet and/or icy climate cycles have shaped the topography of the planet's large craters. Icarus is the journal of the American Astronomical Society's Division of Planetary Sciences.



"Studying crater degradation in potentially ice-rich environments is vital to understanding the geology of craters and their surroundings, as well as for determining whether the ice comes from the atmosphere or from below the ground," said Daniel Berman, a PSI associate research scientist and lead author of the paper.

Berman, along with PSI Senior Scientist David Crown and PSI Research Scientist Leslie Bleamaster III, surveyed the geologic features in two sets of mid-latitude craters. Each set included about 100 craters, with the first set in the Arabia Terra region of the northern hemisphere and the second set in an area east of Hellas basin in the southern hemisphere.

The researchers selected craters that are greater than 20 km (about 12.5 miles) in diameter that have been completely or nearly completely photographed by cameras on various spacecraft, including the Mars Odyssey THEMIS VIS camera, the Mars Global Surveyor Mars Orbiter Camera, and the Viking Orbiter cameras.

They looked specifically for the following erosional or depositional features, the number and sizes of those features, and how the features are oriented (i.e., whether they face the equator or the planet's pole in their hemisphere):

-- Lobate flows - Lobe-shaped flow features that have pitted surfaces and raised ridges on their lateral margins are observed on the walls of some craters. These lobes resemble rock glaciers on Earth.

-- Channels - Narrow channels often breach crater walls and extend outside the craters, as well as across crater floors, These channels may have been formed by flowing water.

-- Crater-wall valleys - Trough-like crater-wall valleys, wider than the above-mentioned channels, typically start at the top of the crater rim and terminate where the wall meets the floor. These valleys are sometimes filled with rough-textured deposits, which may be glacial.

-- Gullies and alcoves - Gullies are typically composed of three parts: alcoves at the head of a channel, channels, and debris fans, and are thought to have been formed by flowing water.

-- Arcuate ridges - These are small, arc-shaped ridges that enclose depressions at the base of crater walls, often below gullies. Berman interprets these to be glacial moraines, remnants of glacial deposits that have since evaporated.

-- Debris aprons - These aprons are pitted and lineated deposits on crater floors. They are similar to debris-covered glaciers or ice-rich landslides seen on Earth.

All of these features suggest a landscape shaped by liquid water and/or ice, Berman said. He found that lobate flows, gullies, and arcuate ridges on the crater walls between latitudes of 30 to 45 degrees face the pole in their hemisphere, whereas equator-facing orientations are more common than pole-facing ones at latitudes between 45 and 60 degrees. In the southern study area, narrow channels generally had pole-facing orientations, whereas wider valleys generally have equator-facing orientations.

The features' pole-facing or equator-facing orientations could result from uneven heating of the crater walls. Ice on walls that get more sunlight would melt faster, causing more water to flow and form the gullies and other features.

Unlike Earth, whose axis only oscillates through an arc of about four degrees over millions of years, Mars appears to have an axis that tilts between vertical and as much as 60 degrees, according to recent studies.

Such tilting could enhance ice deposition, Berman said. When one pole begins leaning toward the sun, ice evaporates and then falls as snow at the other pole, which is getting little sunlight. Such tilting could have caused ice sheets to form in areas that are now ice-free, he added.

Further evidence for flowing ice is found on the crater floors, Berman observed. He found that the floors of small craters slope away from the walls that exhibit erosional/depositional features toward the more pristine ones. These slopes have inclines of about 0.5 to 3 degrees. This suggests that ice-rich materials flowed from one crater wall to the other. Tilting floors are less evident in larger craters, although some have gradually sloping floors where debris apron material is evident.

The PSI team's crater study has led them to make the following conclusions:

-- The orientation of erosional/depositional features (whether they face the equator or the pole) suggests a direct relationship to total solar heating along the crater walls.

-- Differences in the shape and size of various erosional/depositional features can be explained by differences in crater-wall slopes, local topography and orientation.

-- The geologic features and suites of features found in the craters may have been created by multiple cycles of ice-sheet formation in response to changes in the tilt of Mars' rotation axis.

This work was funded by a grant to PSI from NASA's Mars Data Analysis Program (PI David Crown).

[ronatu]

Ice rich? NO!
OIL!!!!

[Дмитрий Виницкий]

И там плавает плот.

[Alex_II]

И там плавает плот.

Это платформа местных нефтяников... Какой ужас - нас опередили...

[ronatu]

The low temperatures on the red planet mean any water would usually be frozen rather than running.

But salts called perchlorates are abundant in the soil of the planet, where temperatures often fall below zero, and can act as a natural anti-freeze.

This suggests there could be liquid water below the surface - increasing the chances of life being able to exist there.

Perchlorates are rare on earth but they make up one per cent of Mars's soil.

They were discovered last year by the robotic arm of NASA's Phoenix lander.

Although the spacecraft could not distinguish between different kinds of perchlorates, the most likely candidates are magnesium and sodium perchlorate.

In strong concentrations these salts can cause water to stay as a liquid in temperatures as low as -35F (-37C), reports New Scientist.

The discovery of perchlorates briefly caused a flurry as scientists believe they could act as a food source for microbes on the planet.

Prof Nilton Renno, of Michigan University, a member of the Phoenix team, said: "It's possible to have liquid almost everywhere where there is ice and the temperature goes above this threshold value – that's most of Mars."

Last month experts also claimed further evidence of the possibility of life on Mars, when methane gas, which scientists said could have either a geological or a biological source, was uncovered.


http://www.telegraph.co.uk/scienceandtechnology/science/space/4689871/Anti-freeze-chemicals-could-indicate-life-on-Mars.html

[KBOB]

Ну вообще-то перхлораты богатые энергией вещева, перхлорат разлагающие бактерии могут легко существовать на Марсе.
На Земле такие извесны давно
http://www.nd.edu/~rnerenbe/PERCHLORATEBACTERIA.htm

[ronatu]

[ronatu]

[ronatu]

Hellas includes the lowest elevations on Mars, and may have once held lakes or seas; layered rock outcrops occur around much of the edge of the basin. At this site, a large impact crater (about 90 kilometers across) was partly filled by layered rocks. These rocks on the crater floor are now eroding and forming strange pits.

Here, the layers are mostly exposed on a steep slope which cuts across much of the image. On this slope, they crop out as rocky stripes, some continuous and others not. The material between the stripes is mostly covered by debris, but some areas of exposed rock are visible. The slope is capped by a thick, continuous layer that armors it against erosion; once this cap is gone, the lower material is removed rapidly, forming the steep slope. At the base of this slope, rocks on the floor of the pit appear bright and heavily fragmented by cracks known as joints.

The variation in rock types suggests that the rocks here were deposited by multiple processes or in different environments. Sites like this may preserve a record of conditions on early Mars.

[ronatu]

 "A large number of independent physical and thermodynamical evidence shows that saline water may actually be common on Mars," said Nilton Renno - a co-investigator on the Phoenix mission.

[В А Д И М]

Марсианская Вечная Мерзлота имени РОНАТУ





 

Мох в тундре? или пурга в голливуде?  :lol:

[ronatu]

http://marsprogram.jpl.nasa.gov/mro/gallery/press/20090325a.html

[ronatu]

My previous post did show:

An images recieved from NASA shows Mars' seasonal cap of carbon dioxide ice as it sublimates (goes directly from ice to vapor) in the Martian spring Photo: AFP/GETTY

The photographs taken last month on Nasa's Mars Reconnaissance Orbiter show plumes of carbon dioxide pouring out of blocks of dry ice as the planet's southern pole warms.

Distinctive ice patterns nicknamed "spiders" because of their shape form at the poles as sunlight causes gas to warm up and escape.

http://www.telegraph.co.uk/news/worldnews/northamerica/usa/5081185/Nasa-orbiter-images-capture-spring-on-Mars.html

[В А Д И М]

мдаааа... зимой подземные города трудно спрятать от глаз человеческих...  

[Aleksandras]

Углём :!:  топят наверно :lol:

[Boo]

Углём! Откуда в Италии мята?! (с)
Мазутом они топят!

[Salo]

http://www.newscientist.com/article/dn16867-subsurface-ice-on-mars-exposed-by-recent-impacts.html

Subsurface ice on Mars exposed by recent impacts
19:22 30 March 2009 by Kelly Beatty, The Woodlands, SkyandTelescope.com
For similar stories, visit the Solar System and Exploring Mars Topic Guides

Impacts are the most ubiquitous geologic features in our solar system. Roughly 1600 named craters (and countless lesser pits) scar the Moon's ancient surfaces. On Earth, where wind and water continually wear down the land, the census of confirmed impact craters stands at just 176.

Mars, a mixed bag of ancient and modern terrains, lies somewhere in between. Over the years spacecraft have glimpsed ever-finer features in the Martian landscape. These days, the HiRISE camera aboard NASA's Mars Reconnaissance Orbiter (MRO) can pick out objects only 0.3 metres in size; the High Resolution Stereo Camera on the European Space Agency's Mars Express is no slouch either, with a ground resolution of 2 metres.

So HiRISE researchers were elated, but not particularly surprised, to discover some small, freshly gouged craters in images taken in 2008. Seen at five sites over a latitude range of 43° to 56° north, the excavations are typically 3 to 6 metres across and a third to two-thirds of a metre deep. One cluster must have appeared sometime between June and August, and a somewhat larger pit showed up between January and September.

What did astound the team were splashes of white seen in and around a handful of these craterlets. Could it be water ice? Colleagues operating the spacecraft's CRISM instrument soon confirmed, for the one case large enough to yield a spectrum, that it was! Apparently fist-sized impactors had punched into a layer of ice hidden by a topping of dust about a third of a metre deep.
Disappearing act

In the months that followed, these snowy splashes gradually faded from view. Water ice isn't stable at the craters' latitudes, so most likely it gradually sublimated, or vaporised, into the atmosphere, leaving behind a veneer of any dust that had been mixed with it.

The disappearing act might also be due in part to a coating of dust blown in from the atmosphere. Either way, notes HiRISE investigator Shane Byrne of the University of Arizona, the icy deposits had to be at least a couple of inches (several centimetres) thick, and they couldn't have been unearthed from more than a foot or two (0.3-0.6 m) down.

Byrne announced these findings on Friday at the Lunar and Planetary Science Conference in The Woodlands, Texas. He points out that prior surveys, particularly one done by the neutron spectrometer aboard NASA's Mars Odyssey orbiter, show that vast reservoirs of ice lay barely buried across most of the planet's polar and mid-latitude regions.
So close

But scientists are only now realising just how near the surface the ice lies – and how easily it can be reached. When NASA's Phoenix lander dropped onto a northern polar plain last May, its braking engine blew off a few inches of loose dirt and revealed slabs of nearly pure ice.

The irony in all this is that the Viking 2 lander, which arrived in September 1976, sits just 800 km southeast of the ice-splashed craterlet shown above, and scientists now realise that a layer of water ice almost certainly lies not far beneath its footpads.

"It's probably just tens of centimetres down," says HiRISE team leader Alfred McEwen. Had Viking's sampling scoop been able to dig a little deeper, he adds, "we might have sampled ice on Mars 30 years ago."

Courtesy of Sky and Telescope magazine

[ronatu]

HAMPTON, Va., April 2 /PRNewswire-USNewswire/ --

NASA scientist Michael Mumma and his team of researchers have discovered methane on Mars, indicating the planet is still alive -- either in a biologic or geologic sense. "The big question is, 'What is the origin of this methane now being released,'" Mumma says.

(Logo: http://www.newscom.com/cgi-bin/prnh/20081007/38461LOGO)

While living systems produce more than 90 percent of Earth's atmospheric methane, other purely geological processes, like oxidation of iron compounds, also release methane.

"Right now, we don't have enough information to tell if biology or geology -- or both -- is producing the methane on Mars," said Mumma. "But it does tell us that the planet is still alive, at least in a geologic sense."

Mumma will speak on the mystery of Martian methane in an afternoon talk at NASA's Langley Research Center in Hampton, Va. The lecture, entitled "Methane on Mars -- Geology, Biology, Neither or Both?" will take place Tuesday, April 7, at 2 p.m. in the Reid Conference Center.

Mumma will present the same lecture for the general public on Tuesday evening at 7:30 p.m. at the Virginia Air & Space Center on Settlers Landing Road in Hampton. The evening talk is free and no reservations are required.

A senior scientist at NASA's Goddard Space Flight Center, Mumma is the founding director of Goddard's Center for Astrobiology. His research interests include planetary and cometary physics and chemistry and the formation, evolution and characterization of planetary systems. Mumma is an elected Fellow of the American Physical Society and has twice received NASA's Medal for Exceptional Scientific Achievement.

NASA news releases are available automatically by sending an e-mail message to Langley-news-requests@lists.nasa.gov with the word "subscribe" in the subject line. You will receive an e-mail asking you to visit a link to confirm the action.

To unsubscribe, send an e-mail message to Langley-news-request@lists.nasa.gov with the word "unsubscribe" in the subject line.

[ronatu]

Tak go/\>keH 6bI/\ BbIr/\RgeTb OKEAH CTAPOro...



   

[korund]

А он так и выглядит, все в точности так как на картинке.
Что не так?