In this talk I will show many features believed to contain water ice and tell about a popular model for how ice moves around on Mars. Knowing where to obtain water is of upmost importance for future Mar 1 This is thought to be an old glacier a?er almost all the ice has gone. What is le? are the moraines—the dirt and debris carried by the glacier. The center is hollowed out because the ice is mostly gone. ESP_028352_2245; 44.2 N and 28.5 E. 2 In contrast, here is a glacier that probably s 3 This CTX image displays features called Lobate Debris Aprons. They are, in essence, wide glaciers that form along mesas. Debris aprons are quite common in some areas of Mars. The area inside the oval will be enlarged in later pictures. B13_006200_2228; 41.4 N and 14.7 E. 4 This close-up HiRISE image is 6 kilometers across. This mesa appears to have debris aprons almost all around it. ESP_28313_2220; 41.4 N and 14.7 E. 5 Here is the area inside the oval enlarged. It could even be enlarged further. The le? side of the image is brain terrain. Narrow ridges make up open-celled brain terrain. Most of the other, wider ridges are called closed-cell brain terrain. ESP_28313_2220; 41.4 N and 14.7 E. 6 Lineated valley fill is found in valleys and is composed of linear structures. Valley fill is very common in large areas of Mars. It seems to form when lobate debris aprons coalesce. When enlarged it shows a complex of shapes. The next two images will expand a part from the center of this image. P16_007359_2220; 41.3 N and 48.9 E. 7 At this magnifica 8 Now, closed-cell and open-cell brain terrain are easily dis 9 Craters containing concentric crater fill are very common in certain regions and can easily be iden<fied from orbit. These craters appear to be almost filled with some sort of material. They have several concentric ridges. This is a CTX image and is therefore 30 kilometers across. P17_007714_2184; 38 N and 75.9 E. 10 This enlarged sec 11 Now, one can see a great deal of closed-cell brain terrain and small areas of open-cell brain terrain. The surface is similar to what we saw on the surface of lobate debris aprons and lineated valley fill. One would guess that all three may contain water ice. Our knowledge of impact craters gives us clues to the nature of CCF. ESP_030526_2185; 38 N and 75.9 E. 12 When a impact crater forms, a deep bowl usually is formed, along with rims. Some 13 We have found that if a crater has a certain diameter, it will have a certain depth when it is formed. 14 By comparing calculated depth diameter ra 15 So 3 features are believed to contain water ice. Radar studies from orbit have already confirmed ice in LDA and LVF. These landscapes can be mapped from orbit. Next, we will examine how water ice may have arrived in these loca 16 An ice-rich mantle from the sky has been suggested to bring in the ice. In the higher la 17 This covering has layers in some spots and is gone in other spots. ESP_028336_1395; 40.164 S and 116.859 E. 18 The inside wall of the crater has up to 4 layers visible in the smooth mantle. Researchers have found 6 layers at other sites. It s believed that the layers are from different events of mantle falling from the sky. The mantle shown here may be rela 19 This 30 km wide CTX image shows gullies along a scarp in the lower right. P14_006536_1460; 34.666 S and 210.6 E. 20 These gullies are formed almost totally in mantle material. Gullies are one of the most significant discoveries of this century. They are thought to have been made by liquid water. These gullies were probably formed when ice in the mantle melted and flowed down the slope. It may take only a few warm hours for liquid water to make progress at eroding a gully. ESP_28860_1450; 34.666 S and 210.6 E. 21 The wide picture at the le? is a 30 km wide CTX image of part of Milankovic Crater, which is in the far north--almost directly north of Olympus Mons. The box is enlarged at the right in a HiRISE image. The depressions are called scallops. The mantle is very thick this far north. The next image will greatly enlarge the right side of the top scallop. P17_007788_2347; 54.3 N and 212 E. ESP_024943_2345; 54.3 N and 212 E. 22 At this resolu 23 This wide CTX image shows linear pits and a wide view of scalloped terrain. The area under the box is greatly enlarged in the next photo. P18_008030_2217; 41.667 N and 87.188 E. 24 Now we see polygons that are classified as low center polygons. They too are thought to form in ice-rich areas. Examples of these can be seen a few hours drive from here in Rocky Mountain Na 25 So, observa 26 The pictures we have looked at have come from the areas outlined in black. There is a popular model that seeks to explain how ice gets to these mid-la 27 Currently Mars is 28 When the 29 So at 30 A half of a year later the sun will be concentrated at the opposite pole. Then, ice is transferred to southern mid-la 31 32