Clipmarks | amgumen's 'mars' clips

Artificial Meteorite Shows Martian Impactors Could Carry Traces Of Life

Thu, 02 Oct 2008 04:22:03 GMT

clipped by: amgumen
clipper's remarks: Unfortunately the heat of reentry was so high, even with a protective two centimetre-thick rock coating, that the organisms were carbonised. They died but their cells still remain as "pompeified" forms.
if martian sedimentary meteorites carry traces of past life, these traces could be safely transported to Earth. However, the results are more problematic when applied to Panspermia, a theory that proposes living cells could be transported between planets. STONE-6 showed at least two centimetres of rock is not sufficient to protect the organisms during entry."

Clip Source: www.spacedaily.com

The STONE-6 experiment tested whether sedimentary rock samples could withstand the extreme conditions during a descent though the Earth's atmosphere where temperatures reached at least 1700 degrees Celsius.

After landing, the samples were transported in protective holders to a laboratory clean-room at ESTEC and examined to see if any traces of life remained.

although about 39 known meteorites from Mars have been identified, all are basaltic rock-types and no sedimentary meteorites have been found to date.

Two samples of terrestrial sedimentary rock and a control sample of basalt were fixed to the heat-shield of the return capsule, which re-entered the atmosphere on 26th September after 12 days in orbit. The basalt was lost during re-entry. However, a sample of

3. 5 billion year old volcanic sand containing carbonaceous microfossils and a 370 million year sample of mudstone from the Orkney Islands containing chemical biomarkers both survived.

Discovery of world's oldest rocks challenged

Tue, 30 Sep 2008 03:23:15 GMT

clipped by: amgumen

Clip Source: environment.newscientist.com

This could make the greenstone belt the oldest known rocks on Earth, just 300 million years younger than our solar system. It also dates them close to the time when a massive object the size of Mars dealt Earth a glancing blow 4.53 billion years ago, knocking off the debris which formed the Moon.

The energy of the blow was such that the Earth's upper layers melted into an ocean of magma. The next period for which we have evidence in the evolution of Earth is around 3.8 billion years ago, by which time most geologists agree plate tectonics were in place.

For the last four years, Jonathan O'Neil of McGill University and colleagues have been studying a large band of ancient rocks in northern Quebec known as the Nuvvuagittuq greenstone belt. However, the team has used a controversial method for dating the rocks.

Mars Lander has photographed several dust devils

Sat, 13 Sep 2008 02:17:02 GMT

clipped by: amgumen

Clip Source: www.physorg.com

At least six different dust devils appear in the images, some of them in more than one image. They range in diameter from about 2 meters (7 feet) to about 5 meters (16 feet).

Phoenix monitors air pressure every day, and on the same day the camera saw dust devils, the pressure meter recorded a sharper dip than ever before. The change was still less than the daily change in air pressure from daytime to nighttime, but over a much shorter time.

A key factor in the whirlwinds getting stronger is an increase in the difference between daytime and nighttime temperatures. Daytime highs at the Phoenix site are still about minus 30 Celsius (minus 22 Fahrenheit), but nighttime lows have been dropping a few degrees, getting close to minus 90 Celsius (minus 130 Fahrenheit).

The same day as the dust devils were seen, the photographed swinging of Phoenix's telltale wind gauge indicated wind speeds exceeding 5 meters per second (11 miles per hour).

Tags: mars

Morning Frost on the Surface of Mars

Thu, 28 Aug 2008 02:39:57 GMT

clipped by: amgumen

Clip Source: www.nasa.gov

Morning Frost on the Surface of Mars

A thin layer of water frost is visible on the ground around NASA's Phoenix Mars Lander in this image taken by the Surface Stereo Imager at 6 a.m. on Sol 79 (August 14, 2008), the 79th Martian day after landing. The frost began to disappear shortly after 6 a.m. as the sun rose on the Phoenix landing site.

Polar layered deposits on Mars: to unravel Mars’ climate history

Sun, 03 Aug 2008 03:59:40 GMT

clipped by: amgumen

Clip Source: hirise.lpl.arizona.edu

Mars, like Earth, appears to have experienced global climate changes over the past few million years. The effects of Earth’s ice ages are well recorded in polar ice in Greenland and Antarctica. Similarly, layered deposits in both polar regions on Mars (see above) appear to record ancient Martian climate variations. Changes in the tilt (relative to the Sun) of the rotation axes of both Earth and Mars are thought to have influenced their climates

Most Mars researchers believe that the polar layered deposits are the result of variations in the amounts of dust and water ice deposited over many climate cycles, but the amount of time needed to form individual layers remains a major uncertainty

Clip Source: hirise.lpl.arizona.edu

The north polar layered deposits of Mars form a layered stack of dusty ice up to 3 kilometers (2 miles) thick. The differences from layer to layer are thought to reflect differences in the climate of Mars that existed when the layers were formed.

Mars: Stairs, Polygons, Dunes and Troughs

Sat, 02 Aug 2008 06:54:17 GMT

clipped by: JohnWaterman

Clip Source: www.universetoday.com

Meridiani Planum on Mars, where the Mars Rover Opportunity has been traversing the past four plus years, is not just covered with flat, endless plains. Of course, Opportunity has been entering and studying a few of the craters in the region. Here's a crater in Meridiani that's a whopper

This crater is so large that the HiRISE image is entirely within it, and the crater rim is not visible. The most prominent feature is layered sedimentary rocks that look like a grand stairway. These rocks have been eroded, most likely by wind, or possibly flowing water.

Click here for a full resolution picture of this area.

HiRISE also has taken some great images of the polygon features found in the high northern latitudes, that form from the ground seasonally freezing and thawing

polygons and a few dunes

This image is from an area

known as Elysium Planitia

just north of Mars’ equator

interesting geologic history

catastrophic floods of water

For more spectacular images, see the HiRISE website.

Tags: astronomy, hirise, mars, planets, solar system

Pavements and Tiled Floors Made by Nature

Sat, 03 May 2008 06:08:14 GMT

clipped by: amgumen

Clip Source: irna.lautre.net

Endurance Crater, Mars

Eagle Crater, Mars

Tags: geology

Dry Debris, Not Water, Caused Recent Flows on Mars

Tue, 29 Apr 2008 04:27:27 GMT

clipped by: amgumen

Clip Source: news.nationalgeographic.com

A dry landslide—not liquid water—is the most likely explanation for at least one of the bright streaks seen recently on Mars

The streaks first made waves in 2006, when scientists reported them in pictures of Martian gullies taken in 2005.

The features had not been in images of the same region from 1999, indicating that something had flowed down those gullies recently.

At the time the researchers figured the most likely candidate was a flash flood—which would have offered proof of liquid water on modern Mars.

The new paper, published this month in the journal Geology, concludes that the shape of at least one of the bright deposits doesn't match the way water would flow.

This doesn't mean that Mars never had water, but it does cast doubt on more recent liquid flowing on the red planet.

The new maps not only provided a more detailed look at the features, they allowed the team to model the flows based on the steepness of the slopes.

Tags: mars

Possible Hot Springs Found on Mars

Tue, 29 Apr 2008 00:01:30 GMT

clipped by: amgumen

Clip Source: news.softpedia.com

There

have been several claims in the past that hot springs were spotted on Mars, however they haven't been confirmed yet. Now, the high-resolution camera on board the Mars Reconnaissance Orbiter took several pictures of what appears to be 'spring like' mounds in Vernal Crater in Arabia Terra.

The features were discovered by Johnson Space Center researchers Carlton Allen and Dorothy Oehler and present two possible ancient hydrothermal springs appearing as light-tones, elliptical structures. According to Allen, the two features bear a striking resemblance to the spring mounds found in Dalhousie, Australia.

Clip Source: news.softpedia.com

Possible spring mounds in Vernal Crater, Arabia Terra, Mars

Clip Source: news.softpedia.com

Spring-like mounds seen in Dalhousie, Australia

Tags: mars

Layers in Aureum Chaos

Mon, 14 Apr 2008 22:59:54 GMT

clipped by: amgumen

Clip Source: apod.nasa.gov

Layers in Aureum Chaos

Explanation: At first glance these undulating shapes in shades of blue might look like waves on an ocean. Seen here in a false-color image from the Mars Reconnaissance Orbiter's HiRISE camera, they are actually layered rock outcrops found in Aureum Chaos. The larger Aureum Chaos region is a chaotic jumble of eroded terrain in the eastern part of Mars' immense canyon Valles Marineris. Distinct layers composing these outcrops could have been laid down by dust or volcanic ash settling from the atmosphere, sand carried by martian winds, or sediments deposited on the floor of an ancient lake. This close-up view of the otherwise red planet spans about 4 kilometers, a distance you might walk over flat ground in less than an hour.

Tags: mars

Mysterious White Rock Fingers on Mars

Mon, 14 Apr 2008 01:18:39 GMT

clipped by: amgumen

Clip Source: apod.nasa.gov

Explanation: What caused this unusual white rock formation on Mars? Intrigued by the possibility that they could be salt deposits left over as an ancient lakebed dried-up, detailed studies of these fingers now indicate that this is not correct. The light material appears to have eroded away from the surrounding area, indicating a very low-density composition, possibly consistent with volcanic ash or windblown dust. The stark contrast between the rocks and the surrounding sand is compounded by the sand's unusual darkness. This picture was taken from the Mars Express spacecraft currently orbiting Mars. Planetary scientist Emily Lakdawalla, among others, has followed her curiosity about this unusual Martian landform into a fascinating investigation that is eloquently described in the Planetary Society Weblog. The mysterious white rock spans about 15 kilometers across inside a larger crater that spans about 100 kilometers.

Tags: mars

Stickney Crater

Mon, 14 Apr 2008 01:13:52 GMT

clipped by: amgumen

Clip Source: apod.nasa.gov

Explanation: Stickney Crater, the largest crater on the martian moon Phobos, is named for Chloe Angeline Stickney Hall, mathematician and wife of astronomer Asaph Hall. Asaph Hall discovered both the Red Planet's moons in 1877. Over 9 kilometers across, Stickney is nearly half the diameter of Phobos itself, so large that the impact that blasted out the crater likely came close to shattering the tiny moon. This stunning, enhanced-color image of Stickney and surroundings was recorded by the HiRISE camera onboard the Mars Reconnaissance Orbiter as it passed within some six thousand kilometers of Phobos last month. Even though the surface gravity of asteroid-like Phobos is less than 1/1000th Earth's gravity, streaks suggest loose material has slid down inside the crater walls over time. Light bluish regions near the crater's rim could indicate a relatively freshly exposed surface. The origin of the curious grooves along the surface is mysterious

Tags: space

Strange Sculptures on Mars

Sun, 23 Mar 2008 02:28:39 GMT

clipped by: amgumen

Clip Source: news.softpedia.com

Strange dunes around Procter crater

Clip Source: news.softpedia.com

The new observations conducted with MRO shows that sediments are deposited with the help of winds mostly on the downwind side of the rocks, and indicate the general directions of most of the winds that blow on the surface of the Red Planet

MRO's camera HiRISE has been able to spot features of the surface of the planet as small as half of a meter high, from distances of over 313 kilometer above.

Considering the fact that winds are rather mild on the surface of Mars, scientists argue that part of these layers of rocks are composed of relatively soft materials which are, most likely, volcanic ash that has been incorporated into rocks during the mixing process with water ice, dry ice and dust.

Such structures are mostly referred to as 'yardangs'

some areas around Victoria Crater presented features similar to those of the yardangs.

Salt Deposits Found on Red Planet

Sun, 23 Mar 2008 01:12:55 GMT

clipped by: amgumen

Clip Source: news.softpedia.com

False color image showing the presence of chloride minerals

Clip Source: news.softpedia.com

Hundreds of small depressions on the surface of Mars reveal salt deposits similar to those found on Earth when water evaporates.

the new evidence found by his team is yet a new confirmation of the theory that Mars might have had liquid water on its surface at some point in time.

The locations of the deposits show that they could have formed 3.8 billion years ago while others appear to be up to a few hundred thousand years younger. Back here on Earth, salt deposits form when large bodies of water evaporate, leaving behind the suspensions that were dissolved in it. Alternatively, similar salt deposits may form in underground

Enlarge picture

brines as a result of water evaporation due to volcanic activity.

on Mars the most likely formation process involved the evaporation of acidic fluids during interactions with basaltic rock.

Tags: geology, mars

Avalanche on Mars -How Cool is That!

Fri, 07 Mar 2008 16:21:04 GMT

clipped by: amgumen

Clip Source: www.dailygalaxy.com

The scarp in this image is on the edge of the dome of layered deposits centered on Mars’ north pole. From top to bottom this impressive cliff is over 700 m (2300 ft) tall and reaches slopes over 60 degrees. The top part of the scarp, to the left of the images, is still covered with bright (white) carbon dioxide frost which is disappearing from the polar regions as spring progresses.

The upper, steepest section, which appears highly fractured due to blocks pulling away from the wall, is the likely source zone for the falls. The precise trigger mechanism is not yet known, although the disappearance of the carbon dioxide frost, the expansion and contraction of the ice in response to temperature differences, a nearby Mars-quake or meteorite impact, and vibrations caused by the first fall in the area, are all possible contributors.

it is extremely rare to catch such a dramatic event as an avalanche in action on Mars north pole.

Tags: mars, geology