It is a 2000 word chemistry research task (yr 11 standard)
Microsoft Word - 20S1 1SCH research - life on Mars (5).docx 1 Specific unit goals measured by this task • understand how models and theories have developed based on evidence from a range of sources, and the uses and limitations of chemical knowledge in a range of contexts • evaluate, with reference to empirical evidence, claims about chemical properties, structures and reactions • communicate, predict and explain chemical phenomena using qualitative and quantitative representations in appropriate modes and genres. Assessment criteria specific to this task • knowledge and understanding • critical thinking • investigative skills • communication skills • effective work practices Word Limit if applicable Absolute limit of 2000 words, excluding references. Rubric Supplied Yes Total Marks Available 26 Submission through box required No Life On Mars? How do you search for chemical evidence of life when you’re 250 million kilometres from your sample? In the late nineteenth century, speculation was rife that Mars was criss-crossed by geometric canals of non-natural origin, and that it must therefore be home to an advanced civilisation1. Since then, the idea of life on Mars has persisted. With the development of robotic space probes and with the engineering of increasingly sophisticated scientific instruments, humanity has invested significant time and money over the last few decades in studying this idea. In the early 2000s, spectroscopic measurements from Earth-based telescopes suggested that there was methane in the Martian atmosphere. This is significant, because methane is a relatively reactive molecule and would only be expected to stay in a planet’s atmosphere for up to a couple of hundred years. Hence if methane is present, there must be a source that replenishes it as it gradually reacts and disappears. There are two main ways methane could be produced – geologically (from chemical reactions occurring in certain types of rocks) or biologically (by certain types of bacteria). In mid-2012, NASA successfully landed the Mars Science Laboratory (MSL) – otherwise known as “Curiosity” – in Gale Crater. Curiosity was built to answer two questions: whether methane is present on Mars, and if so, whether its origin is geological or biological. While the evidence for the presence of methane is now fairly robust, the second question remains unresolved. One of the primary instruments carried on the Curiosity rover is SAM (Sample Analysis at Mars). This is actually a suite of three instruments, one of which is a mass spectrometer. This is used not only to identify different gases in samples taken from the atmosphere, but also to detect the ratios of different isotopes in those samples, which provide clues to the origin of the gases. 1https://www.nasa.gov/audience/forstudents/postsecondary/features/F_Canali_and_First_Martians.html 2 As time passes, Curiosity is being joined on Mars by a variety of other robotic probes. The European Space Agency’s Exomars mission launched their Trace Gas Orbiter in 2016 and will this year launch the Rosalind Franklin rover. The Rosalind Franklin also carries a mass spectrometer – even more sensitive than SAM – which will examine organic molecules in the soil and rock of Mars. The search for life on Mars continues… * * * Your assignment is to write a feature article for a popular science magazine, looking at how the search for life on Mars has played out over the last decade. You should focus on methane in the Martian atmosphere, the results from the Curiosity rover and the use of mass spectrometry as a detection tool, but you may be flexible with the inclusion of other material. It should use language and a level of detail appropriate for a scientifically literate audience. Hints for tackling this task: To do this properly, you will need to read quite a bit about the debate, so brush up your note-taking skills and make sure you do in-text referencing as you write. If you leave it until later, you will forget what information came from which reference, and you’ll waste time trying to figure it out (or you’ll get lazy and miss references). A list of suggested references is provided below. Pay careful attention to the publication date and author of each reference, because in order to make sense of the story, you need to understand the order in which different discoveries were made. Article Structure Use this guide to help plan your article. You do not have to follow the order or headings of the questions below, but you must cover all of them in some way. For ideas about structuring a feature article, flick through some Cosmos or New Scientist magazines in the iC. Try making good use of break-out boxes, pictures and diagrams (remember to reference these if they come from other sources). 1. Provide a descriptive and engaging title for your article. [Communication Skills] 2. Lay out an argument for the importance of looking for evidence of life on Mars. [Critical Thinking] 3. Explain what methane is andwhy it is a molecule of interest in this context. [Knowledge and Understanding, Investigative Skills] 4. Detection Methods a. Choose and outline several detection methods that have been used to analyse the chemistry of Mars. b. Specifically describe the technique of mass spectrometry. How is this being used on the Curiosity rover? c. What is an isotope ratio and why is it important in this research? [Knowledge and Understanding, Investigative Skills] 5. The Data a. Describe the published data that are relevant to the question of life on Mars. While the focus should be on Curiosity, include results from other missions if they help you flesh out the story. 3 [Knowledge and Understanding, Investigative Skills] b. Analyse and evaluate how this data has influenced the various debates relating to the presence and origin of methane and the possibility of life on Mars. [Critical Thinking] 6. Science as a Human Endeavour. As you construct your article, focus on the following two points from the Australian Curriculum strand “Science as a Human Endeavour”. Note that each point has a code. Cite the relevant code in your text when you describe a situation that illustrates one of the points. Science is a global enterprise that relies on clear communication, international conventions, peer review and reproducibility (ACSCH009) Advances in science understanding in one field can influence other areas of science, technology and engineering (ACSCH011) [Critical Thinking] 7. The Big Picture. a. Summarise the current state of the debate. b. Describe the next steps that scientists are taking in the search for life on Mars. [Knowledge and Understanding, Investigative Skills] Bibliography In-text referencing and a full bibliography in Harvard style [Investigative skills] Formatting: Format your article to make it easy to read, but don’t spend excessive amounts of time on the layout. It should look like a magazine article, but content is more important than bling. Plagiarism and Turnitin: Your assignment must be submitted through Turnitin, using the link on the class Moodle page. If submitting through Turnitin messes up your formatting, you may also send me a copy via email. In a complex research-based writing task like this it can happen that you inadvertently use someone else’s wording. To avoid this, follow these pro tips: - read widely (you’re less likely to imitate someone else’s phrasing if you’ve read several sources on the same topic) - make your own dot-point notes as you go - rearrange and assemble your dot-points into a logical story/argument - write it out in your own words - submit to Turnitin early to check for inadvertent plagiarism - leave it for a couple of days (let your brain relax before you attack it again) - edit and improve 4 5 Suggested References Any sources you use from this list must be cited correctly in your bibliography. You may of course use any others you find useful, providing you cite them correctly also. Note: • ‘Astrobiology’, ‘The Economist’, ‘New Scientist’ and ‘Scientific American’ are reputable magazines. • ‘Nature’, ‘Science’, and ‘Astrobiology’ are peer-reviewed scientific journals (note that Astrobiology magazine is different to Astrobiology journal). • NASA and ESA are the American and European space agencies respectively. Getting started: the state of the methane debate in 2010, prior to Curiosity’s launch. • The Economist: http://www.economist.com/node/17797286 • New Scientist: http://www.newscientist.com/article/dn19902-did-martian-methane-signal-come-from-earth.html Does methane on Mars come from a biological or a geological source? • NASA media release: http://www.nasa.gov/home/hqnews/2009/jan/HQ_09-006_Mars_Methane.html • European Space Agency: https://exploration.esa.int/web/mars/-/46038-methane-on-mars • Astrobiology magazine: https://www.astrobio.net/extreme-life/making-sense-of-mars-methane/ Mars Missions Curiosity: • NASA’s mission website for MSL Curiosity: http://mars.jpl.nasa.gov/msl/ • Information on SAM instrument (containing the mass spectrometer): http://www.astrobio.net/news-exclusive/sam-i-am/ Exomars 2016 (Trace Gas Orbiter) and 2020 (Rosalind Franklin rover): • http://exploration.esa.int/mars/ Curiosity’s findings 2012-2013: no methane • Nature, 2013: http://www.nature.com/news/missing-methane-gas-mystifies-mars-scientists-1.13779 2014-2020: detection of methane, water and other organic molecules • Scientific American, 2014: http://www.scientificamerican.com/article/nasa-rover-finds-mysterious-methane-emissions-on-mars/ • Zahnle et al, Science, 2015, “Play it again, SAM.” (Download article as PDF from assessment tab on Moodle page.) • Eric Hand, Science, 2018, “Mars Methane Rises and Falls with the Seasons.” Download article as PDF from Moodle. 6 • NASA press release, 2018: https://mars.nasa.gov/news/8347/nasa-finds-ancient-organic-material-mysterious-methane-on- mars/?site=msl • The Conversation, 2018: https://theconversation.com/discovered-a-huge-liquid-water-lake-beneath-the-southern-pole-of- mars-100523 • NASA press release 2019: https://mars.nasa.gov/news/8452/curiositys-mars-methane-mystery-continues/?site=msl • Alexandra Witze, Nature, 2019: “Mars data deepen methane mystery” (Trace Gas Orbiter results) Download article as PDF from Moodle. • ANU research, 2019: https://www.anu.edu.au/news/all-news/a-step-closer-to-solving-the-methane-mystery-on-mars • Universe Today, 2020: