tag:blogger.com,1999:blog-34250262586466052192024-02-21T12:37:16.004+08:00AreologyAn extraterrestrial photoblog about Mars.JDsghttp://www.blogger.com/profile/04735390644321868222noreply@blogger.comBlogger1802125tag:blogger.com,1999:blog-3425026258646605219.post-43964097341169762782014-12-20T12:00:00.000+08:002014-12-22T19:50:50.456+08:00Daga Vallis<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhxfWTgfe-xJZN-nWhXpOOwQm253vgKcLyGTyvMr8R32x7Y8guGZDO8agEO9b0lxqqbzJj3VhM27Qf1hDWRZw3BEkS86EWGqIQ5iwG8DJS35uEuGX0wNR4WKa4UVpiP8x3UNiseuC7X920/s1600/Daga+Vallis+01+False+Color+by+Themis.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhxfWTgfe-xJZN-nWhXpOOwQm253vgKcLyGTyvMr8R32x7Y8guGZDO8agEO9b0lxqqbzJj3VhM27Qf1hDWRZw3BEkS86EWGqIQ5iwG8DJS35uEuGX0wNR4WKa4UVpiP8x3UNiseuC7X920/s1600/Daga+Vallis+01+False+Color+by+Themis.jpg" height="640" width="320" /></a></div><br />
<blockquote>The THEMIS VIS camera contains 5 filters. The data from different filters can be combined in multiple ways to create a false color image. These false color images may reveal subtle variations of the surface not easily identified in a single band image. Today's false color image shows part of Daga Vallis on Eos Mensa.<br />
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<b>Orbit Number:</b> 2012 <b>Latitude:</b> -11.8784 <b>Longitude:</b> 317.167 <b>Instrument:</b> VIS <b>Captured:</b> 2002-05-29 04:14</blockquote><br />
<b>Image credit:</b> <a href="http://photojournal.jpl.nasa.gov/catalog/PIA18988">NASA/JPL-Caltech/Arizona State University</a>JDsghttp://www.blogger.com/profile/04735390644321868222noreply@blogger.com0tag:blogger.com,1999:blog-3425026258646605219.post-69427724831974769782014-12-17T00:00:00.000+08:002014-12-29T17:38:11.721+08:00Possible Methane Sources and Sinks<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiXhin_pQdK9tz-Ubp6RiHPIj4x_VO_GwuIo_dx-BBO-qHrKgZTOxFp5AWhJFeGZIWJfu8NXS8x9FQc7oDBYnL6sJAzRIfzbBYpDOUMRcJ4giEoAvVHuVcEnJEpFGPhQM2WoemdG1OeGek/s1600/Possible+Methane+Sources+and+Sinks.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiXhin_pQdK9tz-Ubp6RiHPIj4x_VO_GwuIo_dx-BBO-qHrKgZTOxFp5AWhJFeGZIWJfu8NXS8x9FQc7oDBYnL6sJAzRIfzbBYpDOUMRcJ4giEoAvVHuVcEnJEpFGPhQM2WoemdG1OeGek/s1600/Possible+Methane+Sources+and+Sinks.jpg" height="480" width="640" /></a></div><br />
<blockquote>This illustration portrays possible ways that methane might be added to Mars' atmosphere (sources) and removed from the atmosphere (sinks). NASA's Curiosity Mars rover has detected fluctuations in methane concentration in the atmosphere, implying both types of activity occur in the modern environment of Mars.<br />
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A molecule of methane consists of one atom of carbon and four atoms of hydrogen. Methane can be generated by microbes and can also be generated by processes that do not require life, such as reactions between water and olivine (or pyroxene) rock. Ultraviolet radiation (UV) can induce reactions that generate methane from other organic chemicals produced by either biological or non-biological processes, such as comet dust falling on Mars. Methane generated underground in the distant or recent past might be stored within lattice-structured methane hydrates called clathrates, and released by the clathrates at a later time, so that methane being released to the atmosphere today might have formed in the past.<br />
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Winds on Mars can quickly distribute methane coming from any individual source, reducing localized concentration of methane. Methane can be removed from the atmosphere by sunlight-induced reactions (photochemistry). These reactions can oxidize the methane, through intermediary chemicals such as formaldehyde and methanol, into carbon dioxide, the predominant ingredient in Mars' atmosphere.</blockquote><br />
<b>Image credit:</b> <a href="http://photojournal.jpl.nasa.gov/catalog/PIA19088">NASA/JPL-Caltech/SAM-GSFC/University of Michigan</a><br />
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<b>Note:</b> For more information, see:<br />
* <a href="http://photojournal.jpl.nasa.gov/catalog/PIA19086">PIA19086: Tunable Laser Spectrometer on NASA's Curiosity Mars Rover</a><br />
* <a href="http://photojournal.jpl.nasa.gov/catalog/PIA19087">PIA19087: Methane Measurements by NASA's Curiosity in Mars' Gale Crater</a><br />
* <a href="http://photojournal.jpl.nasa.gov/catalog/PIA19089">PIA19089: Some Data from Detection of Organics in a Rock on Mars</a><br />
* <a href="http://photojournal.jpl.nasa.gov/catalog/PIA19090">PIA19090: Comparing 'Cumberland' With Other Samples Analyzed by Curiosity</a><br />
* <a href="http://photojournal.jpl.nasa.gov/catalog/PIA19091">PIA19091: Mars Has Ways to Make Organics Hard to Find</a><br />
* <a href="http://www.jpl.nasa.gov/news/news.php?release=2014-432&rn=news.xml&rst=4413">NASA Rover Finds Active and Ancient Organic Chemistry on Mars</a><br />
* <a href="http://www.jpl.nasa.gov/news/news.php?release=2014-433&rn=news.xml&rst=4414">How NASA Curiosity Instrument Made First Detection of Organic Matter on Mars</a><br />
* <a href="http://science.nasa.gov/science-news/science-at-nasa/2014/16dec_methanespike/">Curiosity Detects Methane Spike on Mars</a>JDsghttp://www.blogger.com/profile/04735390644321868222noreply@blogger.com0tag:blogger.com,1999:blog-3425026258646605219.post-48932710132479600392014-12-12T00:00:00.000+08:002015-01-01T16:28:53.490+08:00Impact Crater in Morava Valles<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgdyNrGtaMWgjJpwRLI-vdBDMdFCSZGUsKR0WOG8ssFPH2VJDcIXbA2vPHfYuhtyljOVRUli8kgstvnta08JgbHRQZmWp_dQu00-cwC28cNxreaRyQt1mLYLlL9R3EKiKwGKzjcGvzAK7k/s1600/Impact+Crater+in+Morava+Valles+by+HiRise.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgdyNrGtaMWgjJpwRLI-vdBDMdFCSZGUsKR0WOG8ssFPH2VJDcIXbA2vPHfYuhtyljOVRUli8kgstvnta08JgbHRQZmWp_dQu00-cwC28cNxreaRyQt1mLYLlL9R3EKiKwGKzjcGvzAK7k/s1600/Impact+Crater+in+Morava+Valles+by+HiRise.jpg" height="400" width="640" /></a></div><br />
<blockquote>Morava Valles is a small outflow channel in the Margaritifer Sinus region of Mars. Several of the interior channels of Morava emanate from a localized region of terrain that is caving in, also called “subsidence.”<br />
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This region, comprised of jumbled blocks of flat-topped hills, is known as chaotic terrain. These channels, which emerge from the chaotic region, are separated by elongated hills that coalesce into a single channel before disappearing into the Margaritifer Chaos to the north. Chaotic terrains are thought to be the regions where ground water erupted catastrophically onto the surface, forming highly erosive flows that carved the outflow channels. The hills just downstream of the chaotic source region were shaped into streamlined islands by the erosive flows, forming blunt rounded ends in the upstream direction and tapering towards the north in the downstream direction.<br />
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Although windblown sediments now cover the original flood-carved channel floor in a sea of dunes, <a href="http://static.uahirise.org/images/2014/details/cut/ESP_038798_1665.jpg">a 1.5 kilometer diameter impact crater</a> provides a window into the sediment on the channel floor. The crater exposes several layers along its upper walls including a distinct bouldery layer just below the mantle of windblown sediments. These boulders may have originated from the eruption site and were transported and emplaced on the channel floor by high energy floods. Alternatively, these bouldery layers may be lava that subsequently flowed across the flood scarred channel floors.</blockquote><br />
<b>Image credit:</b> <a href="http://www.uahirise.org/ESP_038798_1665">NASA/JPL/University of Arizona</a><br />
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<b>Note:</b> For more information, see <a href="http://photojournal.jpl.nasa.gov/catalog/PIA19116">PIA19116: Seeing Beneath the Surface in Morava Valles</a>.JDsghttp://www.blogger.com/profile/04735390644321868222noreply@blogger.com0tag:blogger.com,1999:blog-3425026258646605219.post-476967606122882102014-12-09T00:00:00.000+08:002014-12-30T13:57:27.386+08:00Gale Crater Lake<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgWq0OnVcZpsp-PRtq0y7PK4d-RbU6YHe1HivWAoS69UXTa0mYURFZ-rYA6gV6MDJTv8HcHfxw4-ma8f0qByxBG5ujAj0Rb15ok7pQRkHGPziZTFP1g4V8lvSqstrB_Qd0U0OquWZRHgRQ/s1600/Gale+Crater+Lake.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgWq0OnVcZpsp-PRtq0y7PK4d-RbU6YHe1HivWAoS69UXTa0mYURFZ-rYA6gV6MDJTv8HcHfxw4-ma8f0qByxBG5ujAj0Rb15ok7pQRkHGPziZTFP1g4V8lvSqstrB_Qd0U0OquWZRHgRQ/s1600/Gale+Crater+Lake.jpg" height="400" width="640" /></a></div><br />
<blockquote>This illustration depicts a lake of water partially filling Mars' Gale Crater, receiving runoff from snow melting on the crater's northern rim. Evidence of ancient streams, deltas and lakes that NASA's Curiosity Mars rover mission has found in the patterns of sedimentary deposits in Gale Crater suggests the crater held a lake such as this more than three billion years ago, filling and drying in multiple cycles over tens of millions of years.<br />
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Gale Crater is 96 miles (154 kilometers) in diameter. This view is looking toward the southeast. The land surface in this illustration is the area's modern shape. Three billion years ago, the rim would have been higher and less eroded. A large layered mountain, Mount Sharp, now stands in the middle of Gale Crater. Accumulation of sediments in lakes, deltas, streams and wind-blown deposits is proposed to have formed the layers making up the lower portion of the mountain. When the crater first held a lake, it might have had central peak, much smaller than Mount Sharp, formed as a rebound from the impact that excavated the crater. Such a peak might have appeared as an island in the lake.</blockquote><br />
<b>Illustration credit:</b> <a href="http://photojournal.jpl.nasa.gov/catalog/PIA19080">NASA/JPL-Caltech</a><br />
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<b>Note:</b> For more information, see:<br />
* <a href="http://photojournal.jpl.nasa.gov/catalog/PIA19067">PIA19067: Curiosity Mars Rover's Route from Landing to Base of Mount Sharp</a><br />
* <a href="http://photojournal.jpl.nasa.gov/catalog/PIA19068">PIA19068: Inclined Martian Sandstone Beds Near 'Kimberley'</a><br />
* <a href="http://photojournal.jpl.nasa.gov/catalog/PIA19069">PIA19069: Bedding Pattern Interpreted as Martian Delta Deposition</a><br />
* <a href="http://photojournal.jpl.nasa.gov/catalog/PIA19070">PIA19070: Sets of Beds Inclined Toward Mount Sharp</a><br />
* <a href="http://photojournal.jpl.nasa.gov/catalog/PIA19071">PIA19071: How a Delta Forms Where River Meets Lake</a><br />
* <a href="http://photojournal.jpl.nasa.gov/catalog/PIA19072">PIA19072: Sol 696 (July 22, 2014), Left</a><br />
* <a href="http://photojournal.jpl.nasa.gov/catalog/PIA19073">PIA19073: Multiple Deltas Built Out Over Time</a><br />
* <a href="http://photojournal.jpl.nasa.gov/catalog/PIA19074">PIA19074: Sedimentary Signs of a Martian Lakebed</a><br />
* <a href="http://photojournal.jpl.nasa.gov/catalog/PIA19075">PIA19075: Thin-Laminated Rock in 'Pahrump Hills' Outcrop</a><br />
* <a href="http://photojournal.jpl.nasa.gov/catalog/PIA19076">PIA19076: Cross-Bedding at 'Whale Rock'</a><br />
* <a href="http://photojournal.jpl.nasa.gov/catalog/PIA19077">PIA19077: Crystals May Have Formed in Drying Martian Lake</a><br />
* <a href="http://photojournal.jpl.nasa.gov/catalog/PIA19078">PIA19078: Sediment Accumulation in Dry and Wet Periods</a><br />
* <a href="http://photojournal.jpl.nasa.gov/catalog/PIA19079">PIA19079: Sedimentation and Erosion in Gale Crater, Mars</a><br />
* <a href="http://photojournal.jpl.nasa.gov/catalog/PIA19081">PIA19081: Martian Rock's Evidence of Lake Currents</a><br />
* <a href="http://www.jpl.nasa.gov/news/news.php?release=2014-419&rn=news.xml&rst=4398">NASA's Curiosity Rover Finds Clues to How Water Helped Shape Martian Landscape</a><br />
* <a href="http://science.nasa.gov/science-news/science-at-nasa/2014/08dec_mountsharp/">Mars Mountain was All Wet</a>JDsghttp://www.blogger.com/profile/04735390644321868222noreply@blogger.com0tag:blogger.com,1999:blog-3425026258646605219.post-68780489677963701462014-12-08T00:00:00.000+08:002014-12-30T13:01:24.307+08:00Enigmatic Feature in Athabasca Lava Flows<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhiEIRQxwoHKaHVPkoHaKe9viFbIoWzDI-PspneRjo5yIuuUrnB37NYfeQnIvTGQ63i6JM0t3RJT2a3kdhEsMwIiK85yG_4UtXS3vgMcTU3tQJw3dycdvEUhP4PWAVmXBVi-x2zy-nBY-M/s1600/Enigmatic+Feature+in+Athabasca+Lava+Flows+by+HiRise.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhiEIRQxwoHKaHVPkoHaKe9viFbIoWzDI-PspneRjo5yIuuUrnB37NYfeQnIvTGQ63i6JM0t3RJT2a3kdhEsMwIiK85yG_4UtXS3vgMcTU3tQJw3dycdvEUhP4PWAVmXBVi-x2zy-nBY-M/s1600/Enigmatic+Feature+in+Athabasca+Lava+Flows+by+HiRise.jpg" height="400" width="640" /></a></div><br />
<blockquote>What is this enigmatic landform?<br />
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The circular feature is nearly 2 kilometers (1.2 miles) wide. It looks like a circular island surrounded by a "sea" of smooth-looking lava flows. The Athabasca region contains some of the youngest lava flows on Mars. Therefore, it is highly possible that volcanism played a role in creating this feature.<br />
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<a href="http://static.uahirise.org/images/2014/details/cut/ESP_038646_1805.jpg">Perhaps lava has intruded underneath this mound</a> and pushed it up from beneath. It looks as if material is missing from the mound, so it is also possible that there was a significant amount of ice in the mound that was driven out by the heat of the lava. There are an array of features like this in the region that continue to puzzle scientists.<br />
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We hope that close inspection of this HiRISE image, and others around it, will provide some clues regarding its formation.</blockquote><br />
<b>Image credit:</b> <a href="http://www.uahirise.org/ESP_038646_1805">NASA/JPL/University of Arizona</a><br />
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<b>Note:</b> For more information, see <a href="http://photojournal.jpl.nasa.gov/catalog/PIA18932">PIA18932: An Enigmatic Feature in Athabasca Lava Flows</a>.JDsghttp://www.blogger.com/profile/04735390644321868222noreply@blogger.com0tag:blogger.com,1999:blog-3425026258646605219.post-27024260481013572152014-12-07T00:00:00.000+08:002014-12-27T20:33:25.552+08:00Clays Along the Coprates Chasma Plateau<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh_0atRM6sl2y3ue20Xme7ZHPBEHX1ZaSERDhK96np8BXhmYtC8XqdNVxRX0w_F-3VDXq3loufufq1U6-keL6v7FrKznT4b8GlTVvV4fNBeg0SHeA6KOR5UYuEnjBx-pjaeUqsd5R5BnSg/s1600/Clays+Along+the+Coprates+Chasma+Plateau+by+HiRise.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh_0atRM6sl2y3ue20Xme7ZHPBEHX1ZaSERDhK96np8BXhmYtC8XqdNVxRX0w_F-3VDXq3loufufq1U6-keL6v7FrKznT4b8GlTVvV4fNBeg0SHeA6KOR5UYuEnjBx-pjaeUqsd5R5BnSg/s1600/Clays+Along+the+Coprates+Chasma+Plateau+by+HiRise.jpg" height="400" width="640" /></a></div><br />
<blockquote>This image shows exposures of deposits along the plateau just to the south of Coprates Chasma.<br />
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Whereas Coprates Chasma and many of the other chasmata of Valles Marineris contain kilometer-thick light-toned mounds made up of sulfates, several of the deposits along the plateau have signatures of clays. This indicates that water was here for extensive periods of time to cause the plains to weather and alter into clays.</blockquote><br />
<b>Image credit:</b> <a href="http://www.uahirise.org/ESP_038918_1650">NASA/JPL/University of Arizona</a><br />
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<b>Note:</b> For more information, see <a href="http://photojournal.jpl.nasa.gov/catalog/PIA18933">PIA18933: Clays along the Coprates Chasma Plateau</a>.JDsghttp://www.blogger.com/profile/04735390644321868222noreply@blogger.com0tag:blogger.com,1999:blog-3425026258646605219.post-649646972618811512014-12-06T00:00:00.000+08:002014-12-22T19:46:51.667+08:00Dunes and Wind Streaks in Arabia Terra<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhjSQUdlBbSZQus-UaS5Zb5u4a9_6TT0Nl266XwRjOjNesBlp0K8ayWNvP5W68kTUMvU7ZrOzu6hHs8NsDueqT3NWbx8o7ztwpWOc5ykEiFqXkLYgUeWv-marbBxtbqRaGHnIdM0MmIsKA/s1600/Dunes+and+Wind+Streaks+in+Arabia+Terra+by+HiRise.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhjSQUdlBbSZQus-UaS5Zb5u4a9_6TT0Nl266XwRjOjNesBlp0K8ayWNvP5W68kTUMvU7ZrOzu6hHs8NsDueqT3NWbx8o7ztwpWOc5ykEiFqXkLYgUeWv-marbBxtbqRaGHnIdM0MmIsKA/s1600/Dunes+and+Wind+Streaks+in+Arabia+Terra+by+HiRise.jpg" height="400" width="640" /></a></div><br />
<blockquote>Arabia Terra is one of the more dusty regions on Mars, where ever-falling red dust covers the surface allowing only minor variations in color and tone. One exception is when wind-driven, dark-toned sand moves across the surface ejecting the bright dust into the atmosphere to reveal the dust-free surface below.<br />
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This HiRISE image shows sand dunes with surrounding <a href="http://static.uahirise.org/images/2014/details/ESP_037714_1935.jpg">larger tear drop-shaped light streaks</a> pointing west (or, to the left). This orientation, along with the morphology of the local dunes, indicates winds from the east have stripped sand particles off the dunes and carried them downwind to form these light streaks. More importantly, active sand has a role in the slow erosion of the rocks here and the overall landscape evolution of the region.</blockquote><br />
<b>Image credit:</b> <a href="http://www.uahirise.org/ESP_037714_1935">NASA/JPL/University of Arizona</a><br />
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<b>Note:</b> For more information, see <a href="http://photojournal.jpl.nasa.gov/catalog/PIA18931">PIA18931: Dunes and Wind Streaks in Arabia Terra</a>.JDsghttp://www.blogger.com/profile/04735390644321868222noreply@blogger.com0tag:blogger.com,1999:blog-3425026258646605219.post-5695126555304932732014-12-05T00:00:00.000+08:002014-12-05T00:00:09.082+08:00Braided TARs in Syrtis Major<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi9rDOoLPlj6duMIcL3TyxmL4vEccrb-UpN6SuVG_qqCxXoUsK0qCd8jO0YVpa7t4VEMBGsz_zOFtySsuuP1cLo0ZBZ19mM4GvuR-otxji1nltGF68vizZj_Lz9dEcvI9z1ozr77fJ3tzk/s1600/Braided+TARs+in+Syrtis+Major+by+HiRise.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEi9rDOoLPlj6duMIcL3TyxmL4vEccrb-UpN6SuVG_qqCxXoUsK0qCd8jO0YVpa7t4VEMBGsz_zOFtySsuuP1cLo0ZBZ19mM4GvuR-otxji1nltGF68vizZj_Lz9dEcvI9z1ozr77fJ3tzk/s1600/Braided+TARs+in+Syrtis+Major+by+HiRise.jpg" height="400" width="640" /></a></div><br />
<blockquote>Transverse aeolian ridges (TARs) are commonly found throughout the Martian tropics, including rocky regions such as Syrtis Major that are largely devoid of dust.<br />
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These bright wind-blown ripples most often occur in simple sets of ridges <a href="http://static.uahirise.org/images/2014/details/cut/ESP_038227_2020.jpg">with regular size and spacing</a>. Typical TARs stand a few meters tall and have a wavelength (that is to say, separation) of 30 to 60 meters. HiRISE has not detected any changes among the TARs today, suggesting that they are inactive.<br />
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In this scene, we see TARs with a highly unusual morphology. Instead of single ridges, we see sets of small ridges that are separated by about 50 meters. The smaller ripples are spaced only 5 to 8 meters apart. Between the smaller ripples are even smaller striations that are perpendicular to the ridge crests with regular spacings of less than 2 meters.<br />
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This image raises a number of puzzling questions. Why are the ripples organized into two distinct wavelengths? Did the different wavelengths result from different processes or from different conditions? When did these wavelength-specific conditions or processes take place? Did they occur together, or did they alternate, or did one take place after the other? Were the processes depositional or erosional, or both?<br />
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The complexity of Martian TARs makes us think twice about any single explanation for their origin.</blockquote><br />
<b>Image credit:</b> <a href="http://www.uahirise.org/ESP_038227_2020">NASA/JPL/University of Arizona</a><br />
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<b>Note:</b> For more information, see <a href="http://photojournal.jpl.nasa.gov/catalog/PIA18930">PIA18930: Braided TARs in Syrtis Major</a>.JDsghttp://www.blogger.com/profile/04735390644321868222noreply@blogger.com0tag:blogger.com,1999:blog-3425026258646605219.post-85003557048485420972014-12-04T12:00:00.000+08:002014-12-04T20:17:12.546+08:00False Color Arsia Mons<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg9atry-DK7Ig1iBr15a348oknOdeQ0vBlD00Jl5cwjzegxjifpXouAtJXuLesCsAT025933U9BQjpF_gfh4VWj95QuNHp8MxDtyJwoqlMggVPlN3nzUkTjydT6q2RMUlEQIjY7NxqpgFA/s1600/Arsia+Mons+03+by+Themis.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg9atry-DK7Ig1iBr15a348oknOdeQ0vBlD00Jl5cwjzegxjifpXouAtJXuLesCsAT025933U9BQjpF_gfh4VWj95QuNHp8MxDtyJwoqlMggVPlN3nzUkTjydT6q2RMUlEQIjY7NxqpgFA/s1600/Arsia+Mons+03+by+Themis.jpg" height="640" width="142" /></a></div><br />
<blockquote>This false color image shows part of the summit caldera of Arsia Mons. The mottled bluish tones are from clouds.<br />
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<b>Orbit Number:</b> 56650 <b>Latitude:</b> -9.51318 L<b>ongitude:</b> 239.933 <b>Instrument:</b> VIS <b>Captured:</b> 2014-09-21 07:27</blockquote><br />
<b>Image credit:</b> <a href="http://photojournal.jpl.nasa.gov/catalog/PIA18970">NASA/JPL-Caltech/Arizona State University</a>JDsghttp://www.blogger.com/profile/04735390644321868222noreply@blogger.com0tag:blogger.com,1999:blog-3425026258646605219.post-9808988440706646522014-12-03T12:00:00.000+08:002014-12-04T20:13:58.469+08:00False Color Noctis Labyrinthus<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiUB4q0bqwF2A96Up_A-3quuYHln8sHT7sDyzvuSTHhS-cWF80VC_YihTkDYs94h_ncpJ8c6dcUJYA6_967DauYDNg6VrwKGcIZWgobpQB4D9KUq0SxzEqwY5TIynEqkT8iB4UIyvbITXY/s1600/Noctis+Labyrinthus+05+by+Themis.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiUB4q0bqwF2A96Up_A-3quuYHln8sHT7sDyzvuSTHhS-cWF80VC_YihTkDYs94h_ncpJ8c6dcUJYA6_967DauYDNg6VrwKGcIZWgobpQB4D9KUq0SxzEqwY5TIynEqkT8iB4UIyvbITXY/s1600/Noctis+Labyrinthus+05+by+Themis.jpg" height="640" width="144" /></a></div><br />
<blockquote>This false color image covers part of Noctis Labyrinthus. The bluish tone in the lower elevation depressions may indicate atmospheric haze.<br />
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<b>Orbit Number:</b> 56612 <b>Latitude:</b> -5.85669 <b>Longitude:</b> 255.491 <b>Instrument:</b> VIS <b>Captured:</b> 2014-09-18 04:23</blockquote><br />
<b>Image credit:</b> <a href="http://photojournal.jpl.nasa.gov/catalog/PIA18969">NASA/JPL-Caltech/Arizona State University</a>JDsghttp://www.blogger.com/profile/04735390644321868222noreply@blogger.com0tag:blogger.com,1999:blog-3425026258646605219.post-6400551688900515742014-12-02T12:00:00.000+08:002014-12-04T20:10:56.638+08:00False Color Claritas Fossae<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgQA04uYRQ4x4NP5vMvQOynXjQa4brNEVD0R3_S15tegrhffuTbJnRmWiK2biLQHB-8QKjGdME03zbITINy0Q1xdQ4WCqDyq9qupyYfNwWMmXaGM31uspYmzSsWVnLl17iK6TphBetngnU/s1600/Claritas+Fossae+02+by+Themis.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgQA04uYRQ4x4NP5vMvQOynXjQa4brNEVD0R3_S15tegrhffuTbJnRmWiK2biLQHB-8QKjGdME03zbITINy0Q1xdQ4WCqDyq9qupyYfNwWMmXaGM31uspYmzSsWVnLl17iK6TphBetngnU/s1600/Claritas+Fossae+02+by+Themis.jpg" height="640" width="146" /></a></div><br />
<blockquote>This false color image shows part of Claritas Fossae.<br />
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<b>Orbit Number:</b> 56562 <b>Latitude:</b> -42.1269 <b>Longitude:</b> 263.184 <b>Instrument:</b> VIS <b>Captured:</b> 2014-09-14 01:23</blockquote><br />
<b>Image credit:</b> <a href="http://photojournal.jpl.nasa.gov/catalog/PIA18963">NASA/JPL-Caltech/Arizona State University</a>JDsghttp://www.blogger.com/profile/04735390644321868222noreply@blogger.com0tag:blogger.com,1999:blog-3425026258646605219.post-15607694647755947182014-11-29T12:00:00.000+08:002014-12-04T20:32:40.605+08:00False Color Tithonium and Ius Chasmata<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjut5EhoKMZCfBvmIrAaR9tu6Lcx1-aT2RmZ2-G9CAPlynez8wuLi0eaXf1TtqkTeccjHs733E1F3TeB7v3d0A-nBVPZ9GOUTdrFxU6YFwc5qKVZ7zAiRmFudNLefuSTj3L5FLrbiHU6nI/s1600/Tithonium+and+Ius+Chasmata+01+by+Themis.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjut5EhoKMZCfBvmIrAaR9tu6Lcx1-aT2RmZ2-G9CAPlynez8wuLi0eaXf1TtqkTeccjHs733E1F3TeB7v3d0A-nBVPZ9GOUTdrFxU6YFwc5qKVZ7zAiRmFudNLefuSTj3L5FLrbiHU6nI/s1600/Tithonium+and+Ius+Chasmata+01+by+Themis.jpg" height="640" width="144" /></a></div><br />
<blockquote>This false color image of the region including both Tithonium and Ius Chasmata includes a bluish region in both canyons. This may indicate an atmospheric haze. The potential haze appears to be more widespread in Ius Chasma.<br />
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<b>Orbit Number:</b> 56524 <b>Latitude:</b> -5.5587 <b>Longitude:</b> 273.654 <b>Instrument:</b> VIS <b>Captured:</b> 2014-09-10 22:30</blockquote><br />
<b>Image credit:</b> <a href="http://photojournal.jpl.nasa.gov/catalog/PIA18962">NASA/JPL-Caltech/Arizona State University</a>JDsghttp://www.blogger.com/profile/04735390644321868222noreply@blogger.com0tag:blogger.com,1999:blog-3425026258646605219.post-53187661915635230842014-11-28T12:00:00.000+08:002014-12-04T20:07:20.977+08:00False Color Ascraeus Mons<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgXg-Kz1YlJtb9HiELXdwA1m0_1gADRovyP9JHalAy2C8oVU_aU17FxBjM-7HhYeN4yyVOKU7clBlqaYuZPatflQC54JYVNEvX88_2uFO7mrW0_MtbwpmE7AKlxtBD4avfeY3vMUMfl-0k/s1600/Ascraeus+Mons+12+by+Themis.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgXg-Kz1YlJtb9HiELXdwA1m0_1gADRovyP9JHalAy2C8oVU_aU17FxBjM-7HhYeN4yyVOKU7clBlqaYuZPatflQC54JYVNEvX88_2uFO7mrW0_MtbwpmE7AKlxtBD4avfeY3vMUMfl-0k/s1600/Ascraeus+Mons+12+by+Themis.jpg" height="640" width="148" /></a></div><br />
<blockquote>Today's VIS image is a false color image of part of the northern flank of Ascreaus Mons. The bluish section at the top of the image may indicate an atmospheric haze.<br />
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<b>Orbit Number:</b> 56512 <b>Latitude:</b> 13.2761 <b>Longitude:</b> 257.162 <b>Instrument:</b> VIS <b>Captured:</b> 2014-09-09 22:53</blockquote><br />
<b>Image credit:</b> <a href="http://photojournal.jpl.nasa.gov/catalog/PIA18961">NASA/JPL-Caltech/Arizona State University</a>JDsghttp://www.blogger.com/profile/04735390644321868222noreply@blogger.com0tag:blogger.com,1999:blog-3425026258646605219.post-63210076129418161092014-11-20T00:00:00.000+08:002014-12-01T19:09:09.926+08:00Pink Cliffs<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgO90Gw9GZVK0VB4MJTLR95t2s1GUltW2iPOp0d7d7GdotGsMIcg1VALObIVmej_YxjGqNF8D2GchtypsAea7Dk14BuYWR_hI-YuGB1S7ABQXagSn5hy0lIipudqcKlzHKsw7RKZsVQv14/s1600/Pink+Cliffs+ridge+by+MSL.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgO90Gw9GZVK0VB4MJTLR95t2s1GUltW2iPOp0d7d7GdotGsMIcg1VALObIVmej_YxjGqNF8D2GchtypsAea7Dk14BuYWR_hI-YuGB1S7ABQXagSn5hy0lIipudqcKlzHKsw7RKZsVQv14/s1600/Pink+Cliffs+ridge+by+MSL.jpg" height="236" width="640" /></a></div><br />
<blockquote>This small ridge, about 3 feet (1 meter) long, appears to resist wind erosion more than the flatter plates around it. Such differences are among the rock characteristics that NASA's Curiosity Mars rover is examining at selected targets at the base of Mount Sharp.<br />
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The ridge pictured here, called "Pink Cliffs," is within the "Pahrump Hills" outcrop forming part of the basal layer of the mountain. This view is a mosaic of exposures acquired by Curiosity's Mast Camera (Mastcam) shortly before a two-week walkabout up the outcrop, scouting to select which targets to examine in greater detail during a second pass.<br />
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Pink Cliffs is one of the targets chosen for closer inspection. This image combines several frames taken with the Mastcam on October 7, 2014, the 771st Martian day, or sol of Curiosity's work on Mars. The color has been approximately white-balanced to resemble how the scene would appear under daytime lighting conditions on Earth.<br />
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<a href="http://photojournal.jpl.nasa.gov/tiff/PIA18880_fig1.tif">Figure 1</a> is a version with a scale bar overlaid on the image.<br />
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An image showing the Pahrump Hills walkabout route is at <a href="http://photojournal.jpl.nasa.gov/catalog/PIA19039">PIA19039</a>. An overhead map showing the walkabout drives, from Sol 780 (Oct. 16) to Sol 794 (Oct. 30) is at <a href="http://mars.jpl.nasa.gov/msl/images/Curiosity_Location_Sol803-full.jpg">http://mars.jpl.nasa.gov/msl/images/Curiosity_Location_Sol803-full.jpg</a>.</blockquote><br />
<b>Image credit:</b> <a href="http://photojournal.jpl.nasa.gov/catalog/PIA18880">NASA/JPL-Caltech/MSSS</a>JDsghttp://www.blogger.com/profile/04735390644321868222noreply@blogger.com0tag:blogger.com,1999:blog-3425026258646605219.post-3516686677387801472014-11-19T00:00:00.000+08:002014-12-02T16:27:34.186+08:00Spring in Inca City V<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj3ToQqOsCN6eVOm9sR-y0k90nw76JXxanUcZ3armvHVkLHnJt55eB5_wn3KPGJfed49K4wUeWccV232FnM2ZlxMZwlh3FWioy9V_PWN4uPWDlTS_PNR4kGUYrkB-YgamPL9yHAb1w7LbE/s1600/Spring+in+Inca+City+V+by+HiRise.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEj3ToQqOsCN6eVOm9sR-y0k90nw76JXxanUcZ3armvHVkLHnJt55eB5_wn3KPGJfed49K4wUeWccV232FnM2ZlxMZwlh3FWioy9V_PWN4uPWDlTS_PNR4kGUYrkB-YgamPL9yHAb1w7LbE/s1600/Spring+in+Inca+City+V+by+HiRise.jpg" height="400" width="640" /></a></div><br />
<blockquote>A significant event has occurred in Inca City. The layer of seasonal ice <a href="http://static.uahirise.org/images/2014/details/cut/ESP_038299_0985.jpg">has started to develop long cracks</a>. This is visible in the orange-colored band adjacent to the araneiforms. Fans of dust are emerging from long linear cracks. The cracks form when large plates of ice have no easily ruptured weak spots to release the pressure from gas building up underneath, so the ice simply cracks.<br />
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There are also more fans on the ridge at the top of the image, and more have appeared in between the araneiforms. We do not have any analogous processes occurring naturally on Earth: this is truly Martian.</blockquote><br />
<b>Image credit:</b> <a href="http://www.uahirise.org/ESP_038299_0985">NASA/JPL/University of Arizona</a><br />
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<b>Note:</b> For more information, see <a href="http://photojournal.jpl.nasa.gov/catalog/PIA18896">PIA18896: Spring in Inca City V</a>.JDsghttp://www.blogger.com/profile/04735390644321868222noreply@blogger.com0tag:blogger.com,1999:blog-3425026258646605219.post-59464716587621118262014-11-18T00:00:00.000+08:002014-12-01T19:08:55.171+08:00Spring in Inca City IV<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh5PqaLrsPiPP0UsuRYrbfc8MPGFlpzyynk1BbxA0cD6ld7nNGozcAj1tP68ngZvlYGjRL_MOmC01ypAOH-Q_QcsClIBcr6VHZzA3a1jStKv1c0ytKNofrCdc5CjsnXmKq6Mpj8IhBtX9g/s1600/Spring+in+Inca+City+IV+by+HiRise.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEh5PqaLrsPiPP0UsuRYrbfc8MPGFlpzyynk1BbxA0cD6ld7nNGozcAj1tP68ngZvlYGjRL_MOmC01ypAOH-Q_QcsClIBcr6VHZzA3a1jStKv1c0ytKNofrCdc5CjsnXmKq6Mpj8IhBtX9g/s1600/Spring+in+Inca+City+IV+by+HiRise.jpg" height="400" width="640" /></a></div><br />
<blockquote>At certain times in spring, fans <a href="http://static.uahirise.org/images/2014/details/cut/ESP_038022_0985.jpg">take on a gray or blue appearance</a>. This is the time in Inca City when this phenomenon happens.<br />
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On the ridge at the top of the image fans have lengthened and now look more gray than the blotches on the araneiforms. At the bottom of the image they are distinctly blue in color.<br />
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Two theories have been suggested: perhaps fine particles sink into the seasonal layer of ice so they no longer appear dark. Or, maybe the gas that is released from under the ice condenses and falls to the surface as a bright fresh layer of frost. It is quite likely that both of these theories are correct.</blockquote><br />
<b>Image credit:</b> <a href="http://www.uahirise.org/ESP_038022_0985">NASA/JPL/University of Arizona</a><br />
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<b>Note:</b> For more information, see <a href="http://photojournal.jpl.nasa.gov/catalog/PIA18895">PIA18895: Spring in Inca City IV</a>.JDsghttp://www.blogger.com/profile/04735390644321868222noreply@blogger.com0tag:blogger.com,1999:blog-3425026258646605219.post-64357404246099041892014-11-17T00:00:00.000+08:002014-11-29T18:06:21.441+08:00Spring in Inca City III<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhLtPzV6GFYcOGMRodRnrr_OG6QtKT_l5QmWliwVQYE4sLELuBuGmruHBx2IOwiPyj9deaFEWVUUxfmMr_y16bd_6W8qBB44LLkEa1rUunSUvY9zIjXoE2wb_Vur93H69oAg4smncdtKg4/s1600/Spring+in+Inca+City+III+by+HiRise.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhLtPzV6GFYcOGMRodRnrr_OG6QtKT_l5QmWliwVQYE4sLELuBuGmruHBx2IOwiPyj9deaFEWVUUxfmMr_y16bd_6W8qBB44LLkEa1rUunSUvY9zIjXoE2wb_Vur93H69oAg4smncdtKg4/s1600/Spring+in+Inca+City+III+by+HiRise.jpg" height="400" width="640" /></a></div><br />
<blockquote>In Inca City another week has passed, and <a href="http://static.uahirise.org/images/2014/details/cut/ESP_037877_0985.jpg">there are a few more fans on the ridge</a>. We are studying the sequence of spring activity with the help of citizen scientists at the <a href="http://www.planetfour.org/">Planetfour website</a>, sponsored by Zooniverse.<br />
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Citizens of planet Earth log on and identify and measure fans and blotches in the South polar region of Mars imaged by HiRISE. With their help we can study the polar weather by looking at how the fan directions change through the spring.<br />
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We see how the number of fans and blotches depends on the thickness of the ice layer and how high the sun is in the sky. If you would like to be a part of this endeavor join us at <a href="http://www.planetfour.org/">www.planetfour.org</a>.</blockquote><br />
<b>Image credit:</b> <a href="http://www.uahirise.org/ESP_037877_0985">NASA/JPL/University of Arizona</a><br />
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<b>Note:</b> For more information, see <a href="http://photojournal.jpl.nasa.gov/catalog/PIA18894">PIA18894: Spring in Inca City III</a>.JDsghttp://www.blogger.com/profile/04735390644321868222noreply@blogger.com0tag:blogger.com,1999:blog-3425026258646605219.post-16878853522534216692014-11-16T00:00:00.000+08:002014-11-19T14:54:11.877+08:00Spring in Inca City II<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhcAkTIKMG2G9YsX3vvUfdKFfbpiDxK7WT5NaYrdkGqSwI7ERlH2cjdegZSyONcSR7pLc3RUrHnE4BHlQmmGaARvnFB23hd1twecasTAr-oaOSx9GLhZumSqx5uLtiYoA6asBOZSagLbbY/s1600/Spring+in+Inca+City+II+by+HiRise.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhcAkTIKMG2G9YsX3vvUfdKFfbpiDxK7WT5NaYrdkGqSwI7ERlH2cjdegZSyONcSR7pLc3RUrHnE4BHlQmmGaARvnFB23hd1twecasTAr-oaOSx9GLhZumSqx5uLtiYoA6asBOZSagLbbY/s1600/Spring+in+Inca+City+II+by+HiRise.jpg" height="400" width="640" /></a></div><br />
<blockquote>It is about two weeks later in Inca City and the season is officially spring. Numerous changes have occurred. Large blotches of dust cover the araneiforms. Dark spots on the ridge show places where the seasonal polar ice cap has ruptured, releasing gas and fine material from the surface below.<br />
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<a href="http://static.uahirise.org/images/2014/details/cut/ESP_037811_0985.jpg">At the bottom of the image</a> fans point in more than one direction from a single source, showing that the wind has changed direction while gas and dust were flowing out. Was the flow continuous or has the vent opened and closed?</blockquote><br />
<b>Image credit:</b> <a href="http://www.uahirise.org/ESP_037811_0985">NASA/JPL/University of Arizona</a><br />
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<b>Note:</b> For more information, see <a href="http://photojournal.jpl.nasa.gov/catalog/PIA18893">PIA18893: Spring in Inca City II</a>.JDsghttp://www.blogger.com/profile/04735390644321868222noreply@blogger.com0tag:blogger.com,1999:blog-3425026258646605219.post-35187041960231467552014-11-15T00:00:00.000+08:002014-11-18T13:50:28.224+08:00Spring in Inca City I<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgy3xi_CggmO9IQtcby4Dkf4PhkNCqmH-4b2P6On3QnPOST3hWZY9xDq_eXPMRlnJH08q5LLoXs2W5Vyq5dBbL1p2p8Lw_8ux1Eixx5_vlHMDGcTrctYPVMWGTEVpEw7BvvLqffJ23Sy5M/s1600/Spring+in+Inca+City+I+by+HiRise.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgy3xi_CggmO9IQtcby4Dkf4PhkNCqmH-4b2P6On3QnPOST3hWZY9xDq_eXPMRlnJH08q5LLoXs2W5Vyq5dBbL1p2p8Lw_8ux1Eixx5_vlHMDGcTrctYPVMWGTEVpEw7BvvLqffJ23Sy5M/s1600/Spring+in+Inca+City+I+by+HiRise.jpg" height="400" width="640" /></a></div><br />
<blockquote>Every winter a layer of carbon dioxide ice — or, dry ice — condenses in the Southern polar region, forming a seasonal polar cap less than 1 meter deep. Early in the spring the ice layer begins to sublimate (going directly from a solid to gas) from the top and bottom of the ice layer. Under the ice gas pressure builds up until a weak spot in the ice layer ruptures. The gas rushes out and as it escapes it erodes a bit of the surface.<br />
<br />
Fine particles are carried by the gas to the top of the ice and then fall out in fan-shaped deposits. The direction of the fan shows the direction either of the wind or down the slope. If the wind is not blowing a dark blotch settles around the spot the gas escaped.<br />
<br />
This region is known informally as Inca City, and <a href="http://static.uahirise.org/images/2014/details/cut/ESP_037626_0985.jpg">it has a series of distinctive ridges</a>. On the floor between the ridges are radially organized channels, known colloquially as spiders, more formally called "araneiforms." The channels have been carved in the surface over many years by the escaping pressurized gas. Every spring they widen just a bit.<br />
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This was the first image to be acquired after the sun rose on Inca City, marking the end to polar night. A few fans are visible emerging from the araneiforms.</blockquote><br />
<b>Image credit:</b> <a href="http://www.uahirise.org/ESP_037626_0985">NASA/JPL/University of Arizona</a><br />
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<b>Note:</b> For more information, see <a href="http://photojournal.jpl.nasa.gov/catalog/PIA18892">PIA18892: Spring in Inca City I</a>.JDsghttp://www.blogger.com/profile/04735390644321868222noreply@blogger.com0tag:blogger.com,1999:blog-3425026258646605219.post-79279969874991352202014-11-02T00:00:00.000+08:002014-11-13T15:04:09.440+08:00Partially-Filled Impact Crater in Elysium Planitia<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiYnQMQIbyTIAufqWYuz9GEmhYIf9RWPIiUDpV2SXYLaWX9wbmYd8pL55LuMrqA_1gZPbnxtsq2OUMLP1ezi0LRBIt_UVMLoMBkKCY93MeyeyXV8oc8ko8YBXA2UAatHSKypNCXhHKiXqg/s1600/Partially-Filled+Impact+Crater+in+Elysium+Planitia+by+HiRise.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="400" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiYnQMQIbyTIAufqWYuz9GEmhYIf9RWPIiUDpV2SXYLaWX9wbmYd8pL55LuMrqA_1gZPbnxtsq2OUMLP1ezi0LRBIt_UVMLoMBkKCY93MeyeyXV8oc8ko8YBXA2UAatHSKypNCXhHKiXqg/s640/Partially-Filled+Impact+Crater+in+Elysium+Planitia+by+HiRise.jpg" width="640" /></a></div><br />
<blockquote>This image shows an impact crater that was cut by lava in the Elysium Planitia region of Mars. The relatively flat, shallow floor, rough surface texture, and possible cooling cracks seem to indicate that the crater was partially filled with lava. The northern part of the image also shows a more extensive lava flow deposit that surrounds the impact ejecta of the largest impact crater in the image.<br />
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Which way did the lava flow? It might appear that the lava flowed from the north through the channel into the partially filled crater. However, <a href="http://static.uahirise.org/images/2014/details/cut/ESP_035969_1825.jpg">if you look at the anaglyph with your red and blue 3D glasses</a>, it becomes clear that the partially filled crater sits on top of the large crater's ejecta blanket, making it higher than the lava flow to the north. Since lava does not flow uphill, that means the explanation isn't so simple.<br />
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We have seen much evidence for lava flows in this region that flowed to much higher levels than the present surface, then deflated or drained away. That may have happened here: lava flowed from from north to south to fill this crater, but then it drained back to the north, carving this channel.<br />
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The topographic information that we gained from having a stereo pair let us answer a question that we could not have with only a single image. This is a great example of why we take stereo images, where the two images are used to make a 3D image.</blockquote><br />
<b>Image credit:</b> <a href="http://www.uahirise.org/ESP_035969_1825">NASA/JPL/University of Arizona</a><br />
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<b>Note:</b> For more information, see <a href="http://photojournal.jpl.nasa.gov/catalog/PIA18887">PIA18887: Which Way is Up?</a>JDsghttp://www.blogger.com/profile/04735390644321868222noreply@blogger.com0tag:blogger.com,1999:blog-3425026258646605219.post-66861590692081524702014-11-01T00:00:00.000+08:002014-11-06T21:42:45.017+08:00Hardened Dunes in Arcadia Planitia<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgD11NrJ5ZHBkd7P4qxNuYOVQA4xrGMO7vySCwu4E-Yqxdh2YMqaeLuUx0D1DkIFvd0-v-c5wZJlxPxdDhkPQDpeyjbJONaNGZkVjDZyUXXCwq3fnsk9CD96OjYeBw5VPgCuo9rsg2Ldz8/s1600/Hardened+Dunes+in+Arcadia+Planitia+by+HiRise.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgD11NrJ5ZHBkd7P4qxNuYOVQA4xrGMO7vySCwu4E-Yqxdh2YMqaeLuUx0D1DkIFvd0-v-c5wZJlxPxdDhkPQDpeyjbJONaNGZkVjDZyUXXCwq3fnsk9CD96OjYeBw5VPgCuo9rsg2Ldz8/s1600/Hardened+Dunes+in+Arcadia+Planitia+by+HiRise.jpg" height="400" width="640" /></a></div><br />
<blockquote>HiRISE, with its high resolution and 8 years in orbit about Mars, has shown that <a href="http://www.uahirise.org/ESP_028575_1890">many dunes and ripples on the planet are active</a>. This demonstrates that in some areas sand is loose enough and winds strong enough, that significant change can occur.<br />
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Nevertheless, other Martian dunes are clearly *inactive*. This image in Arcadia Planitia shows dunes in a crater. Unlike active dunes on the planet, those here are bright, and, zooming in, there are several lines of evidence indicating that the dunes have become indurated, that is, hardened <a href="http://static.uahirise.org/images/2014/details/cut/ESP_038143_2205-1.jpg">into cohesive sediment or even into sandstone rock</a>. For example, the dune field at the southern edge is cut off by a step cliff, indicating erosion of hard material. Although fine scale ripples on the original dune surface are preserved, we also see large scale fluting from southwest to northeast, a common texture associated with wind-induced sand abrasion.<br />
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How these dunes became indurated is unknown. One possibility is that this area of Mars was buried and then exhumed, a process that seems to have occurred many times in the Martian past over <a href="http://www.uahirise.org/PSP_001374_1805">various areas of the planet</a>. During burial, compaction and possibly ground water circulation would have indurated the dunes, leaving them as a hard sandstone that, when exhumed, was subsequently partially eroded.<br />
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Note: a version of the cutout is with only the scale bar is <a href="http://static.uahirise.org/images/2014/details/cut/ESP_038143_2205-2.jpg">here</a>.</blockquote><br />
<b>Image credit:</b> <a href="http://www.uahirise.org/ESP_038143_2205">NASA/JPL/University of Arizona</a><br />
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<b>Note:</b> For more information, see <a href="http://photojournal.jpl.nasa.gov/catalog/PIA18890">PIA18890: Hardened Dunes in Arcadia Planitia</a>.JDsghttp://www.blogger.com/profile/04735390644321868222noreply@blogger.com0tag:blogger.com,1999:blog-3425026258646605219.post-8231739435189779462014-10-31T00:00:00.000+08:002014-11-04T17:18:38.506+08:00Sand Forming at a Channel in Athabasca Valles<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjiVV5hmQN08pI_dNpemBLgFRDYmJS_WF4hjDh1YkfNgv0SQc2QyOiPMDjQg0F98kD_3BLAI8kes3cOHAbPG-yU5ofLIPDBZe3QVKgiJtN5uaQEHgIfRAEkbA6bDbX2bB2JIsfX_SNhWRg/s1600/Sand+Forming+blue+at+a+Channel+in+Athabasca+Valles+by+HiRise.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjiVV5hmQN08pI_dNpemBLgFRDYmJS_WF4hjDh1YkfNgv0SQc2QyOiPMDjQg0F98kD_3BLAI8kes3cOHAbPG-yU5ofLIPDBZe3QVKgiJtN5uaQEHgIfRAEkbA6bDbX2bB2JIsfX_SNhWRg/s1600/Sand+Forming+blue+at+a+Channel+in+Athabasca+Valles+by+HiRise.jpg" height="400" width="640" /></a></div><br />
<blockquote>This image shows a small channel cutting into young volcanic lavas in a region where massive catastrophic flooding took place in the relatively recent past. The Athabasca Valles region includes a vast lava flow, thought to be the youngest on Mars, with even younger outflow channels that were carved by running water. The source of the water is believed to be the Cerberus Fossae valleys to the north, which may have penetrated to an over-pressurized aquifer in the subsurface.<br />
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Nowadays, erosion by gravity, wind, and frost gradually wears down the rims of the outflow channels. In this scene, <a href="http://static.uahirise.org/images/2014/details/cut/ESP_038224_1890-1.jpg">we see dark materials along the channel rim</a> that were probably exposed by this erosion. The dark materials are less red than the surrounding surface and so they appear blue in this enhanced color picture. Viewed close up, the dark materials show ripples that suggest they are made up of mobile sand. It is possible that this sand originated elsewhere and simply collected where we see it today, but the fact that sand is not found elsewhere in the scene suggest to us that it is eroding out of the volcanic layers at the retreating rim of the channel.<br />
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Sand sources are important because mobile sand grains have only a limited lifetime, wearing down and chipping apart each time they impact the surface. Erosion of the volcanic materials in this region may provide sands to replace those that are destroyed. Few such sand sources have so far been identified on Mars.</blockquote><br />
<b>Image credit:</b> <a href="http://www.uahirise.org/ESP_038224_1890">NASA/JPL/University of Arizona</a><br />
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<b>Note:</b> For more information, see <a href="http://photojournal.jpl.nasa.gov/catalog/PIA18889">PIA18889: Sand Sources Near Athabasca Valles</a>.JDsghttp://www.blogger.com/profile/04735390644321868222noreply@blogger.com0tag:blogger.com,1999:blog-3425026258646605219.post-87059030501474187812014-10-30T00:00:00.000+08:002014-11-02T21:10:45.482+08:00Possible Landing Site of the Mars 3 Lander<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhZZ6Zuaoh9MvTCVzMl0ThYSTn9WcvuZqoUbJFxMsOQMUqbF2DmIClzaq2V2cD2jhMppwue6DrKpzM_pkGr7lyNX6CWF5-ziojvZjCeJSIBkTXwJMhHGmLfXQjf9wNo0sWaQ0WJupyo0Js/s1600/Possible+Landing+Site+of+the+Mars+3+Lander+by+HiRise.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhZZ6Zuaoh9MvTCVzMl0ThYSTn9WcvuZqoUbJFxMsOQMUqbF2DmIClzaq2V2cD2jhMppwue6DrKpzM_pkGr7lyNX6CWF5-ziojvZjCeJSIBkTXwJMhHGmLfXQjf9wNo0sWaQ0WJupyo0Js/s1600/Possible+Landing+Site+of+the+Mars+3+Lander+by+HiRise.jpg" height="400" width="640" /></a></div><br />
<blockquote>Despite the recent successes of missions landing on Mars, like the Mars Science Laboratory (Curiosity) or the arrival of new satellites, such as India's MOM orbiter, the Red Planet is also a graveyard of failed missions.<br />
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The Soviet Mars 2 lander was the first man-made object to touch the surface of the Red Planet when it crashed landed on 27 November 1971. It is believed that the descent stage malfunctioned after the lander entered the atmosphere at too steep an angle. Attempts to contact the probe after the crash were unsuccessful.<br />
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HiRISE acquired this image to aid in the search for the missing lander. If the Mars 2 debris field is found it could serve as a future landing location for a mission to study the effects of crash landing on the Martian surface and effects of aging on man-made objects.<br />
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This caption is based on the original science rationale. To date, the debris field has not been located, <a href="http://www.uahirise.org/ESP_031036_1345">but this spot was noted as a probable location for the Mars 3 lander</a>.</blockquote><br />
<b>Image credit:</b> <a href="http://www.uahirise.org/ESP_037371_1350">NASA/JPL/University of Arizona</a><br />
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<b>Note:</b> For more information, see <a href="http://photojournal.jpl.nasa.gov/catalog/PIA18888">PIA18888: Search for the Mars 2 Debris Field</a>. The Mars 3 Lander is believed to have landed in Ptolemaeus Crater.JDsghttp://www.blogger.com/profile/04735390644321868222noreply@blogger.com0tag:blogger.com,1999:blog-3425026258646605219.post-12582705441305422612014-10-18T00:00:00.000+08:002014-12-29T18:06:12.995+08:00Perennial Frost in a Vastitas Borealis Crater<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiRfAnRU5EutXVuxiRjfZZjEYRoFyyLwNUtcUn1KEG7ZBtr6saX25cA2IUh9QQetiRgJaKnPtr9YzWEh440xg73OZELmx9TXhWUjH4W270ONTRkteUcztQUkGxLNaYwZ885jz8iBcPYAJE/s1600/Perennial+Frost+in+a+Vastitas+Borealis+Crater+by+HiRise.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiRfAnRU5EutXVuxiRjfZZjEYRoFyyLwNUtcUn1KEG7ZBtr6saX25cA2IUh9QQetiRgJaKnPtr9YzWEh440xg73OZELmx9TXhWUjH4W270ONTRkteUcztQUkGxLNaYwZ885jz8iBcPYAJE/s1600/Perennial+Frost+in+a+Vastitas+Borealis+Crater+by+HiRise.jpg" height="400" width="640" /></a></div><br />
<blockquote>Most surface ice on Mars is temporary. The polar layered deposits are thick stacks of permanent water ice at each pole, and the South Polar residual cap may be a permanent (although dynamic) layer of carbon dioxide ice. However, at lower latitudes, seasonal frost (mostly carbon dioxide, but some water ice) comes and goes each year.<br />
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Some outliers of water ice are found near the North Polar layered deposits. In many cases these have accumulated significant thickness, as in Louth Crater. In this case, a thin layer of bright frost was visible in a HiRISE image in early summer, covering part of the wall of a crater. However, the thickness was small—there is little visible effect on the topography of the crater. HiRISE monitored this location through the rest of the season and found that the frost remained all summer, so this is a perennial ice patch, although the edges shrank slightly over the summer.<br />
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Carbon dioxide is not stable under summer conditions, so this is likely a patch of water ice. It may be that it is in the early stages of accumulation, or that the equilibrium amount of ice in a small crater relatively far from the pole is thin.<br />
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A still-unexplained feature of this crater is the diffuse dark smudges visible on the crater floor. These resemble “defrosting spots” which are visible on carbon dioxide ice in the early spring, but they occur on frost-free areas and survive throughout the summer.</blockquote><br />
<b>Image credit:</b> <a href="http://www.uahirise.org/ESP_037551_2540">NASA/JPL/University of Arizona</a><br />
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<b>Note:</b> This crater is located in Vastitas Borealis to the southwest of Korolev Crater. For more information, see <a href="http://photojournal.jpl.nasa.gov/catalog/PIA18832">PIA18832: Perennial Frost in a Crater on the Northern Plains</a>.JDsghttp://www.blogger.com/profile/04735390644321868222noreply@blogger.com0tag:blogger.com,1999:blog-3425026258646605219.post-5056559787552707302014-10-17T12:00:00.000+08:002014-12-29T18:10:13.701+08:00Candor Chasma<div class="separator" style="clear: both; text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjfhJ0_2dZKEVRLGDvaeDLBzvVE6rCmr5rGXZnAA-YDo9MlgymCseEnXZ9sVFE3vJSS3Ae-NMNuEPuTHlFfrViWrWlIKBWE1nyY8oiNf3QipaT6IkUgWXUomTLWpHcRJMW8UNqOGOn5z1M/s1600/Candor+Chasma+09+by+THEMIS.jpg" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjfhJ0_2dZKEVRLGDvaeDLBzvVE6rCmr5rGXZnAA-YDo9MlgymCseEnXZ9sVFE3vJSS3Ae-NMNuEPuTHlFfrViWrWlIKBWE1nyY8oiNf3QipaT6IkUgWXUomTLWpHcRJMW8UNqOGOn5z1M/s1600/Candor+Chasma+09+by+THEMIS.jpg" height="640" width="306" /></a></div><br />
<blockquote>Today's VIS image shows part of the floor of Candor Chasma.<br />
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<b>Orbit Number:</b> 56461 <b>Latitude:</b> -6.12623 <b>Longitude:</b> 290.797 <b>Instrument:</b> VIS <b>Captured:</b> 2014-09-05 18:01</blockquote><br />
<b>Image credit:</b> <a href="http://photojournal.jpl.nasa.gov/catalog/PIA18750">NASA/JPL-Caltech/Arizona State University</a>JDsghttp://www.blogger.com/profile/04735390644321868222noreply@blogger.com0