Seton Keough High School Team: Victoria Alexander, Nicole Backert, Sarah Balles, Emily Burgess, Sarah Tillman Teacher Mentor: Mr.

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1 Seton Keough High School Team: Victoria Alexander, Nicole Backert, Sarah Balles, Emily Burgess, Sarah Tillman Teacher Mentor: Mr. Bill Mason Professional Mentor: Mr. Sébastien Besse

2 What did we study? Various lunar rilles on the moon (in particular, subjects found in areas of the Marius Hills and Aristarchus Plateau). Why rilles? There is less information on rilles than on other lunar features like craters. What was the point in studying rilles? To create explanations of the aspects of their formation. Study of rilles/lava tubes can lead to lunar habitat.

3 What are sinuous rilles? Long meandering channels in the moon s surface, previously likened to riverbeds. Formation theories Lava erosion Collapsed lava tubes Sunken mare, created by lava floods Sunken crust between parallel faults Apollo 15 Metric Mapping Camera Image of Aristarchus Plateau

4 Begin in a crateriform depression. Decrease in width and depth towards end. Avoid topographic highs. Termination of rille and later reappearance is due to an intact lava roof. Usually are found around other volcanic features, indicating origin. High concentrations around Marius Hills, Aristarchus Plateau, Mare Imbrium, and Mare Orientale Head of Schroter's Valley near Aristarchus, from AS Close up of Mare Serenitatis Apollo Image AS15-M-1116

5 Areas Studied Other High Concentrations Mare Orientale Lunar Nearside mosaic from NASA Lunar Reconnaissance Orbiter

6 Where did we measure the rilles? In the Marius Hills and Aristarchus areas. How did we measure? We used a software, ImageJ, to measure a rille s length, displacement, and sinuosity. Lunar sinuosity formula: (length of rille/length of rille course) What does it tell us? Comparison of rilles in different areas. Form possible theories of the formations of rilles. Determine what makes rilles sinuous.

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8 Rille Length (m) Shortest Length (m) Sinuosity (l/sl) Displacement (m) Dispacement Sinuosity Measurements Summary Length Measurements Summary , 4% x< 20, m , 7 4% 3, % , % ,000 x<40, m , 22% , 8% m Less than , 7% ,000 x<60,000 20,000 x<40, , 11% m , 15% 17, 65% 40,000 x<60, , 20, 63% 74% 60,000 x<80, m ,000 x m Average:

9 Marius Hills Elevation Map Reference Point for Measurements km

10 Sinuosity Distance from Highest Elevation (m) Sinuosity Distance from Peak Rille Number on of Elevated Area Map

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12 Rille Length (m) Shortest length (m) Sinuosity (l/sl) Displacement (m) 1, 4% 1, 4% , 15% 4, 4, 15% , 23% 10, 10, 38% 39% , 4, 8% 15% 3, 12% Displacement Sinuosity Length Measurements Measurements Summary Summary x< x< 20,000 20,000 m m 20,000 x<40,000 Less than ,000 x<40,000 m m 40,000 x<60, ,000 x<60,000 m m 60,000 x<80, ,000 x<80,000 m m 80,000 x<100,000 Greater than ,000 x m m 100,000 x m , 15% 8, 31% 9, 35% 8, 31% Average:

13 Aristarchus Plateau Elevation Map Reference Points for Measurements km References used in places that seem to have most significance in affecting sinuosity.

14 Sinuosity Distance from Peak of Elevated Area Rille Number on Map Sinuosity Distance from Elevation (m)

15 Contains a secondary rille a rille within a rille. Formed after the primary rille, Schroter. Mimics the shape of Schroter but much more sinuous. Cratering along rille, especially inside head of primary. Due to decreasing depth of Schroter towards the end, the lava on the secondary rille was able to flow overtop of primary. Scroter s Valley in Apollo 15 image AS Theory: When lava flows through a rille, it is constantly cooling around the edges. At the end of a rille, lava has become considerably cooler and starts to collect at bottom of rille, explaining decrease of depth. - This could explain increase in depth of secondary rille.

16 Rille Formation Start as Lava Tubes (which can cause cratering) Lava Erosion OR Lava Tubes that Transition to Lava Erosion Continue Sinuosity based on slope of rille Amount of slopes and topographic highs differ per region of moon, which affects average sinuosity End Termination with fading depth and width due to lava build-up Rille Measurements Aristarchus more sinuous than Marius Hills Aristarchus has longer rilles Longer displacement consistent with this data Rilles on Marius Hills more affected by elevation Seems to suggest that many rilles formed before topographic highs on Aristarchus Marius Hills also a smoother transition from high to low

17 Fielder, Gilbert. Geology and Physics of the Moon: A Study of Some Fundamental Problems. Amsterdam [u.a.: Elsevier, Print. Guest, John, and Ronald Greeley. Geology on the Moon. London: Wykeham Publications, Print. Google Images Lunar Reconnaissance Orbiter Camera (LROC)