I m a g e c o ur t e s y o f E S A 2 0 0 7 M P S f r o O I S R I S T Glaciers on Mars: e a m M P S / U P D / L looking for the ice A M / I A A / R S S D / I N T A / One of the scientists’ main U P M / D A S interests in Mars research is P / I D water. Is there water on Mars? A True-colour image of Mars. The image was acquired in 2007 from a distance of about 240 000 km; its resolution is about 5 km/pixel. By Miguel A. de Pablo and Juan D. Centeno Do you know the composi- that Mars had liquid water millions tion of the Martian polar of years ago – flowing on its surface, caps? filling the basins of impact craters, t the expected time, the orbiter, forming lakes, flowing downslope of The northern polar cap of flying at about 300 km in alti- some volcanoes’ flanks, from the Mar- Mars is mainly H O ice. tudeA and around 3.5 km.s-1, focused 2 tian highlands to the lowlands, where However, the southern toward the surface of the arid, cold an extensive ocean could have existed polar cap comprises H O and reddish planet and opened the 2 (referred to as Oceanus Borealis). ice and CO2 ice. shutter of the complex and precise BACKGROUND Solid water is a different matter. Ice camera. A new image from the Mar- polar caps on Mars were identified tian surface, and gigabytes of data, from telescopes and clearly recognis- were then recorded at the same time. – never before have so many experts able on orbiters’ imagesw6, and frozen This process has been repeated many shared so much information and pro- soils have been confirmed in several times in recent decades by the differ- duced so many models and results. places on the planet, mostly thanks to ent orbiters, landers and roversw1 that we have sent to our nearest planet. Water and ice on Mars Every new image and data set increas- One of the scientists’ main interests w2,w3 es the incredibly huge database in Mars research is water. Is there Image courtesy of ESA of information on Mars. Scientists water on Mars? Where is it? Is it liquid from all around the world use these or frozen? In the past, were there resources to study the planet’s chemi- oceans, seas, lakes and rivers on Mars? cal, physical, climatic and geological How did they disappear? Is their environment, with the aim of under- disappearance related to the past and standing more about Mars and how present climate of the planet? But also: it – and even Earth – has evolved. This Is there, or was there, life on Mars? widespread availability of imagesw4 And could humans live there one day? and data is one of the most amazing Thanks to the data acquired by orbit- phenomena in the history of science ers, landers and roversw5, we know The ExoMars rover 12 I Science in School I Issue 28 : Spring 2014 www.scienceinschool.org Cutting edge science Image courtesy of NASA/JPL/HiRISE/University of Arizona HiRISE image of Mars from NASA’s Mars Reconnaissance Orbiter mission, showing the surface with very high resolution (0.35 m/pixel), enough to identify features as small as 1 m in size. ence of ice and glacial-related features using new high-resolution (as high as 35 cm/pixel) images acquired by the active missions of NASA and the European Space Agency (ESA). Our research group focused on the north- west flank of the Hecates Tholus vol- Physics cano in the Elysium region of Mars, Ages 10-11+ at tropical latitudes of the northern Earth science The article is interesting hemisphere. We analysed all the avail- because the teachers and able images from different orbiters stu dents can understand covering this region (at different spec- that currently research can mean temperature of Mars is about tral, temporal and spatial resolutions), be done if you spend many -80 ºC during daytime; at the Equa- and observed features that we inter- hours in search of free inter- tor, the sunny slopes in the summer at preted to be caused by glacial erosion national databases, if you or sedimentation: moraines, crevasses, noon hours can reach a surface temp- Physics compare many images and erature of 15 ºC. roches moutonnées, glacial cirques, of course if you have ex- hanging valleys, eskers, drumlins or arêtes, among othersw9. pertise in a scientific field. Studying martian glaciers Then you can emit a theory Our interpretations were based on w7 which has to be proved by Today, research on Martian ice fo- the comparison between the mars- another research and so on. cuses on finding evidence of the pres- forms (the reliefs observed on Mars) The supplementary links Image courtesy of NAS/JPL/HiRISE/University of Arizona and educational resources can be the starting point for inquiry based learning projects with the title like these: Earth and Mars Simi- larities, Studying the Mars Planet or Life on Mars. Corina Lavinia Toma, Com- puter Science High School “Tiberiu Popoviciu” REVIEW Cluj Napoca, Romania the images reported by NASA’s Phoe- nix mission at high latitudes. The low temperatures of the planet through- out the year, measured by different This unusual structure with traces of a glacier is located in Promethei Terra at the landers and rovers (such as Viking I eastern rim of the Hellas Basin. A so-called ‘block’ glacier flowed from a flank and II, Mars Pathfinder, Spirit, Oppor- of the massif, past mountains several thousand metres high, into a bowl-shaped tunity and Curiosity, which arrived on impact crater, nine kilometres wide, which has been filled nearly to the rim. The Mars in August 2012), confirm that block glacier then flowed into a 17 kilometre wide crater, 500 metres below, ice is stable at all latitudes. In fact, the taking advantage of downward slope. www.scienceinschool.org Science in School I Issue 28 : Spring 2014 I 13 Did you know that Mars had Images courtesy of NASA/JPL/University of Arizona ice ages? Polygonal terrain near the northern po- Crater counting has provided lar cap of Mars, where water ice was evidence of glacial activity, observed just a few centimeters below both ancient (more than 1000 the surface. million years ago) and recent (less than 2 million years ago). The cold periods in Mars history are related to orbital changes (mainly changes to spin axis angle) – just like Earth, where the orbital cycles control most of the Quaternary climate change, as discovered by Milutin BACKGROUND Milankovic in 1922! Images courtesy of NASA Polygonal terrain, typical of frozen soil areas on Earth, surrounding the Phoenix landing site. and the terrestrial landforms in the work in front of the computerw8 and Alps, Iceland or Antarctica, where on different field trips, and thanks to we conducted fieldwork looking for the satellite images and topographic, terrestrial analogues. We also used spectrometric and thermal data, we the ‘multiple working hypotheses’ carried out a detailed description, scientific method to discard other pro- mapping and age determination of the cesses that are able to produce similar features observed on the flank of the features as the origin of the marsforms Martian volcano. Our first conclusion, we observe. Then, after months of based on the long list of glacial-related features on the Hecates Tholus vol- cano, is that an important amount of ice existed there for a long time, form- ing glaciers that flowed downslope, Did you know that Martian sculpting the flanks of the edifice. volcanoes had glaciers? The problem is… we couldn’t find Many Martian volcanoes ice anywhere! However, we could see show reliefs on their flanks some glacial features that we know that are caused by glacial can’t survive for long after ice melts. ice flows – just as we see on This is the case for crevasses: fractures Earth. Those volcanoes are in the glacier disappear when ice located not at polar but at melts or sublimates. We didn’t see the tropical latitudes. Olympus ice on this part of Mars, but we could Mons, Ascraeus Mons and recognise the crevasses sculpted in the View of the Hecates Tholus volcano, Hecates Tholus are examples dust layer that covers the ice. For that in the Elyisum region of Mars, and of volcanoes with glaciers, reason, our second conclusion is that the area in which glacial marsforms similar to Mount Kiliman- the ice causing the extensive fields of have been observed. The area was jaro (Tanzania) and Cotopaxi glacial marsforms must still be below chosen because its high concentration of glacial forms found during general (Ecuador) on Earth. the surface – or it melted very, very BACKGROUND exploration of the volcano slopes. recently. 14 I Science in School I Issue 28 : Spring 2014 www.scienceinschool.org Cutting edge science Partial view of the geomorphological map showing multiple glacial-related features, highlighting the potential Earth science glacier tongues. Colours are part of a conventional map legend: blue hues Image courtesy of Miguel A. de Pablo and Juan D. Centeno represens glacial areas. A B Images courtesy of HiRISE/UA/NASA and DigitalGlobe Similarities between marsforms in Physics Hecates Tholus (A) and landforms in Deception Island, Antarctica (B) help scientists to deduce their origin – in this case, glacial ridges are observed in the images (black arrows). A B Crevasses (fractures on the ice due to its flow) on Hecates Tholus (A) and on glaciers on Deception Island, Antarctica (B), where they are cov- ered by volcanic deposits from the last eruption in 1970.