MRo

6

The Amazing Technicolor Landscape of Mars

High resolution digital terrain models, or DTMs, are topographic maps of Mars as imaged by the High-Resolution Imaging Science Experiment (HiRISE) on board NASA’s Mars Reconnaissance Orbiter (MRO). They are created by grabbing two separate images of the same region of the Martian surface during different orbits. These “stereo pairs” (with different angles of inclination) are used to precisely measure the elevation of the landscape after a complex and time consuming series of steps including calibration by mission scientists and calculations by a powerful algorithm. The result is nothing short of beautiful. So get immersed in Mars’ technicolor landscape and see the scale of some of those awesome geological formations on the Red (blue, green and yellow) Planet. View the entire gallery…

Dry ice pits on Mars

Part of Mars is defrosting. Around the South Pole of Mars, toward the end of every Martian summer, the warm weather causes a section of the vast carbon-dioxide ice cap to evaporate. Pits begin to appear and expand where the carbon dioxide dry ice sublimates directly into gas. These ice sheet pits may appear to be lined with gold, but the precise composition of the dust that highlights the pitwalls actually remains unknown. The circular depressions toward the image center measure about 60 meters across. The HiRISE camera aboard the Mars-orbiting Mars Reconnaissance Orbiter captured the above image in late July. In the next few months, as Mars continues its journey around the Sun, colder seasons will prevail, and the thin air will turn chilly enough not only to stop the defrosting but once again freeze out more layers of solid carbon dioxide.

Image credit: HiRISE, MRO, LPL (U. Arizona), NASA

3

Mars Orbiters ‘Duck and Cover’ for Comet Siding Spring Encounter

NASA is taking steps to protect its Mars orbiters, while preserving opportunities to gather valuable scientific data, as Comet C/2013 A1 Siding Spring heads toward a close flyby of Mars on Oct. 19.

The comet’s nucleus will miss Mars by about 82,000 miles (132,000 kilometers), shedding material hurtling at about 35 miles (56 kilometers) per second, relative to Mars and Mars-orbiting spacecraft. At that velocity, even the smallest particle – estimated to be about one-fiftieth of an inch (half a millimeter) across – could cause significant damage to a spacecraft.

NASA currently operates two Mars orbiters, with a third on its way and expected to arrive in Martian orbit just a month before the comet flyby. Teams operating the orbiters plan to have all spacecraft positioned on the opposite side of the Red Planet when the comet is most likely to pass by.

The European Space Agency is taking

similar precautions

to protect its Mars Express (MEX) orbiter.

  • For more information about the Mars flyby of comet Siding Spring, click here.
Credit: NASA/JPL-Caltech
4

Mind-Blowing Beauty of Mars’ Dunes: HiRISE Photos

Mars plays host to a huge number of dune fields – regions where fine wind-blown material gets deposited to form arguably some of the most beautiful dunes that can be found on any planetary body in the solar system. Using the powerful High-Resolution Imaging Science Experiment (HiRISE) camera on board NASA’s Mars Reconnaissance Orbiter, planetary scientists have an orbital view on these features that aid our understanding of aeolian (wind-formed) processes and Martian geology. Here are some of our favorite Mars dunes as seen by HiRISE.

A hole in Mars

What created this unusual hole in Mars? The hole was discovered by chance in 2011 on images of the dusty slopes of Mars' Pavonis Mons volcano taken by the HiRISE instrument aboard the robotic Mars Reconnaissance Orbiter currently circling Mars. The hole appears to be an opening to an underground cavern, partly illuminated on the image right. Analysis of this and follow-up images revealed the opening to be about 35 meters across, while the interior shadow angle indicates that the underlying cavern is roughly 20 meters deep. Why there is a circular crater surrounding this hole remains a topic of speculation, as is the full extent of the underlying cavern. Holes such as this are of particular interest because their interior caves are relatively protected from the harsh surface of Mars, making them relatively good candidates to contain Martian life. These pits are therefore prime targets for possible future spacecraft, robots, and even human interplanetary explorers.

Image credit: NASA, JPL, U. Arizona

Winter View of Dunes

Looking a bit like chocolate mountains with forests of chocolate pine trees, these are in fact dunes from the southern hemisphere on Mars during the winter-time. The brighter tones are thought to be carbon dioxide or water frost. This is an enhanced-color view generated from images acquired by the High Resolution Imaging Science Experiment (HiRISE) camera on NASA’s Mars Reconnaissance Orbiter (MRO).

lakes: Surface of Mars, photographed by Mars Reconnaissance Orbiter, 24th August 2008.

Detail of Tikhonravov Crater interior at 13°N 35°E. Mikhail Tikhonravov (1900-1974) was a Soviet rocket and spacecraft designer.

It appears that this is an ancient lake bed, now filled with dust. A paper by Fasset and Head groups Tikhonravov with other lakes that survived until the end of the Noachian or early Hesperian era (about 3.5 billion years ago) and estimates that it had a greater volume than the largest freshwater lake on Earth.

Image credit: NASA/JPL/UoA.

Changing Seasons on Mars

The High Resolution Imaging Science Experiment (HiRISE) camera on NASA’s Mars Reconnaissance Orbiter snapped this series of false-color pictures of sand dunes in the north polar region of Mars. The area covered in each of the five panels is about 0.8 mile (1.3 kilometers) wide.

The progression begins at left (Panel A) in early spring, when the ground is covered by a seasonal layer of carbon dioxide ice (dry ice) about 2 feet thick. As spring progresses the ice cracks (Panel B), releasing dark sand from the dune below. When pressurized gas trapped below the ice layer is released, it carries along sand and dust to the top of the ice layer, where it is dropped in fan-shaped deposits downhill and downwind (panels C and D). The final panel shows more and more of the dark dunes as the overlying layer of seasonal ice evaporates back into the atmosphere.

The location in this series of images is at 80 degrees north latitude, 122.5 degrees east longitude.

image: NASA/JPL-Caltech/Univ. of Arizona

Weird Geological Features Spied on Mars

The High-Resolution Imaging Science Experiment (HiRISE) camera carried by NASA’s Mars Reconnaissance Orbiter (MRO) has spotted a strange geological feature that, for now, defies an obvious explanation. Found at the southern edge of Acidalia Planitia, small pits with raised edges appear to hug a long ridge. So far, mission scientists have ruled out impact craters and wind as formation processes, but have pegged the most likely cause to be glacial in nature.

Seasonal changes on Mars

Researchers using NASA’s Mars Reconnaissance Orbiter see seasonal changes on far-northern Martian sand dunes caused by warming of a winter blanket of frozen carbon dioxide.

Earth has no naturally frozen carbon dioxide, though pieces of manufactured carbon-dioxide ice, called “dry ice,” sublime directly from solid to gas on Earth, just as the vast blankets of dry ice do on Mars. A driving factor in the springtime changes where seasonal coverings of dry ice form on Mars is that thawing occurs at the underside of the ice sheet, where it is in contact with dark ground being warmed by early-spring sunshine through translucent ice. The trapped gas builds up pressure and breaks out in various ways.

Transient grooves form on dunes when gas trapped under the ice blanket finds an escape point and whooshes out, carrying out sand with it. The expelled sand forms dark fans or streaks on top of the ice layer at first, but this evidence disappears with the seasonal ice, and summer winds erase most of the grooves in the dunes before the next winter.

The findings reinforce growing appreciation that Mars today, however different from its former self, is still a dynamic world, and however similar to Earth in some respects, displays some quite unearthly processes.

With three Martian years (six Earth years) of data in hand from the Mars Reconnaissance Orbiter’s High Resolution Imaging Science Experiment (HiRISE) camera, the researchers report on the sequence and variety of seasonal changes. The spring changes include outbursts of gas carrying sand, polygonal cracking of the winter ice blanketing the dunes, sandfalls down the faces of the dunes, and dark fans of sand propelled out onto the ice.

Image credit: NASA/JPL-Caltech/Univ. of Arizona

What you’re looking at is a form of hydrated silica known to most as the gemstone opal. Yes, this opal. However, the reason it doesn’t look like its familiar form…

…is because the image above is from the HiRISE camera currently taking pictures of that mysterious 4th rock from the sun. And as the name of this spacecraft suggests…it’s wayyy high up.

Yes, you read that right - we found opal on Mars.

The Compact Reconnaissance Imaging Spectrometer (CRISM) uses “reflective spectroscopy” to visualize the mineralogy of the Martian surface. So let’s zoom in on that crater for a better look….


In the central peak of the crater (exaggerated image above), pink indicate the presence of opal in a hydrated silica form. It’s shown in the infrared, red, and blue/green via sensors from the CRISM imaging spectrometer aboard the Mars Reconnaissance Orbiter; and the location this was found was not Earth, but indeed, Mars, in the crater south of the Baldet Crater.

Why is this so intriguing? Because opal has a high water content. And on Earth, opals have been found to contain fossils and other signs of life. So, if you wish to make an apple pie fr- wait…no…

…if you wish to find preserved life to understand the rich history of Mars, you must first find the fossils.

And this seems like a pretty good place to start.

Navigate your biological spaceships over to the CRISM web site devoted to this marvelous instrument.

Source: PlanetarySociety; Image via NASA/JPL

Ancient Flood Channels Cut Deep into Mars

Relatively recently, water blasted out from an underground aquifer on Mars, carving out deep flood channels in the surface that were later buried by lava flows, radar images complied from an orbiting NASA probe shows.

In a nutshell, the Mars Reconnaissance Orbiter has used radar to look inside Mars’ crust, under a layer of ancient lava, exposing a valley that was formed by a huge surge of water! If that’s not crazycool, I don’t know what is.

Fresh crater exposing buried ice on Mars

A meteorite impact that excavated this crater on Mars exposed bright ice that had been hidden just beneath the surface at this location: latitude 43.9 degrees north, longitude 204.3 degrees east. The 100-meter scale bar at lower right is 109 yards.

Image credit: NASA/JPL-Caltech/Univ. of Arizona 

dghelaayce’e: Surface of Mars, photographed by Mars Reconnaissance Orbiter, 17th November 2008.

High latitude gullies”, inside the northeast rim of Porter Crater, 52°S 247°E.

Russell William Porter (1871-1949) was, at times, an arctic explorer, astronomer, telescope engineer, professor of architecture, painter and technical illustrator.

In 1906, Porter joined an expedition to Alaska led by Frederick Cook. While Porter explored and surveyed the surrounding region, Cook and one other explorer set off to climb Denali, North America’s tallest mountain (aka Mount McKinley; 6,000m or 20,000 feet). Cook eventually returned, claiming success, and Porter became the first of many skeptics: Cook’s ascent was soon shown to have been falsified; he had actually climbed and photographed a much smaller nearby mountain now evocatively named “Fake Peak”.

Porter is best remembered for designing and hand-crafting many telescopes and observatories, including the initial sketches for the Griffith Observatory in the Hollywood hills, and contributions to the 200-inch Hale Telescope at Mount Palomar.

Image credit: NASA/JPL/UoA. 

It Only Happens on Mars: Carbon Dioxide Snow is Falling on the Red Planet

In 2008, we learned from the Phoenix Mars lander that it snows in Mars northern hemisphere — perhaps quite regularly – from clouds made of water vapor. But now, Mars Reconnaissance Orbiter data has revealed the clearest evidence yet of carbon-dioxide snowfalls on Mars. Scientists say this is the only known example of carbon-dioxide snow falling anywhere in our solar system.

“These are the first definitive detections of carbon-dioxide snow clouds…we firmly establish the clouds are composed of carbon dioxide — flakes of Martian air — and they are thick enough to result in snowfall accumulation at the surface.”
- Paul Hayne, JPL; author of a new study published in the Journal of Geophysical Research

Scientists have known for decades that carbon-dioxide exists in ice in Mars’ seasonal and permanent southern polar caps. Frozen carbon dioxide, sometimes called “dry ice” here on Earth, requires temperatures of about -125 Celsius (-193 degrees Fahrenheit), which is much colder than needed for freezing water.

Even though we like to think Mars is a lot like Earth, findings like this remind us that Mars is indeed quite different. But just as the water-based snow falls during the winter in Mars’ northern hemisphere, the CO2 snowfalls occurred from clouds around the Red Planet’s south pole during winter in the southern hemisphere.

Observations by NASA’s Mars Reconnaissance Orbiter have detected carbon-dioxide snow clouds on Mars and evidence of carbon-dioxide snow falling to the surface. Image credit: NASA/JPL-Caltech

Hayne and six co-authors analyzed data gained by looking at clouds straight overhead and sideways with the Mars Climate Sounder, one of six instruments on the Mars Reconnaissance Orbiter. This instrument records brightness in nine wavebands of visible and infrared light as a way to examine particles and gases in the Martian atmosphere. The analysis was conducted while Hayne was a post-doctoral fellow at the California Institute of Technology in Pasadena.

The data provide information about temperatures, particle sizes and their concentrations. The new analysis is based on data from observations in the south polar region during southern Mars winter in 2006-2007, identifying a tall carbon-dioxide cloud about 500 kilometers (300 miles) in diameter persisting over the pole and smaller, shorter-lived, lower-altitude carbon dioxide ice clouds at latitudes from 70 to 80 degrees south.

“One line of evidence for snow is that the carbon-dioxide ice particles in the clouds are large enough to fall to the ground during the lifespan of the clouds…another comes from observations when the instrument is pointed toward the horizon, instead of down at the surface. The infrared spectra signature of the clouds viewed from this angle is clearly carbon-dioxide ice particles and they extend to the surface. By observing this way, the Mars Climate Sounder is able to distinguish the particles in the atmosphere from the dry ice on the surface.”
- David Kass, JPL and co-author of the study

Mars’ south polar residual ice cap is the only place on the Red Planet where frozen carbon dioxide persists on the surface year-round. Just how the carbon dioxide from Mars’ atmosphere gets deposited has been in question. It is unclear whether it occurs as snow or by freezing out at ground level as frost. These results show snowfall is especially vigorous on top of the residual cap.

“The finding of snowfall could mean that the type of deposition — snow or frost — is somehow linked to the year-to-year preservation of the residual cap,” Hayne said.

“Swiss Cheese Terrain” on Mars South Pole residual CO2 ice cap. Credit: NASA/JPL/University of Arizona

In 2008, science teams from the Phoenix mission were able to observe water-ice clouds in the Martian atmosphere and precipitation that fell to the ground at night and sublimate into water in the morning. Phoenix scientist James Whiteway and his colleagues said that clouds and precipitation on Mars play a role in the exchange of water between the ground and the atmosphere and when conditions are right, snow falls regularly on Mars.

“Before Phoenix we did not know whether precipitation occurs on Mars,” Whiteway said. “We knew that the polar ice cap advances as far south as the Phoenix site in winter, but we did not know how the water vapor moved from the atmosphere to ice on the ground. Now we know that it does snow, and that this is part of the hydrological cycle on Mars.”

It will be interesting to follow up on this discovery and learn more about Mars CO2 cycle and how it might affect the Martian atmosphere and surface processes.

Source: UniverseToday; NASA; Stellar Eyes