Are we alone in the Universe? This age old question has gained momentum recently with scientific heavyweights such as Stephen Hawking entering the debate. A newer question has recently been posed, however: should we announce ourselves to other intelligent life in the universe by broadcasting a message into the depths of space? Some scientists consider this strategy, termed ‘Active SETI’, to be a dangerous one – others argue it may be the only way to answer the question within our lifetimes. What do your students think?
The aims of this lesson revolve around the debate of whether other worlds could offer habitable environments and the possibility of any life that exists being capable of receiving and transmitting messages. Students carry out research to develop their understanding on both sides of the scientific and moral arguments for and against the Active SETI approach. The highlight for students is working in teams to attempt to design a communication of their own; you may decide to enter your best examples in an international competition that is open to all, including teams of leading international scientists.
WHY TEACH THIS?
The subject of space is one that continues to captivate students of all ages. At the moment there are a vast number of projects reaching fruition, such as New Horizons, as well as initiatives to broaden the search for extra-terrestrial life with SETI@home and Active SETI. Space travel is showcased on the big screen with films such as Interstellar and The Martian. Studying space encourages students to become part of the ethical and scientific debates surrounding our role in discovering and communicating with life outside of Earth. These activities also encourage students to look at Earth and features of extremophile survival and geology that may have parallels on Mars and Pluto.
STARTER ACTIVITY
A Goldilocks planet
In this activity students work in groups to try and draw a plan of what a habitable planet would be like. They should consider the Earth and its resources including, for example, the atmosphere, rocks, temperature, availability of oxygen and water. More able students might consider the type of star and the likely distance the planet would be from it.
Encourage students to consider other planets within our own solar system and compare and contrast the conditions. Good examples to use are Venus, closer to the Sun, and Mars, which is further away. Internet resources that can help to form a plan include Earthsky [AR1] and an incredible interactive resource from the New York Times [AR2], which shows a tally of 1000+ Kepler planets and an animation of their orbiting around their sun. This shows the relative size and characteristics of the stars, the planets themselves and their orbits (including size and speed).
MAIN ACTIVITIES
1. Project Haystack: The search for life in the galaxy
This detailed and well-resourced sequence of activities has been designed by the SETI Institute [AR3] to engage students of all ages. Within the resources, Project Haystack [AR4] has a number of scenarios that explore what it means to send and receive messages across interstellar distances divided into ‘Missions’.
To complete all the missions would require a sustained length of time and could form an ongoing project for a science club. For a shorter sequence within a lesson or couple of lessons why not select from missions 8-12, where students can build, test and experiment with a radio receiver, learning their applications in the search for life in our galaxy? In mission 10 they are challenged to find a simulated signal that has been sent through space and must decipher its meaning. In the final mission, 12, students imagine the impact on our culture of receiving a message from an extra-terrestrial intelligence by role-playing various special interests at a mock scientific conference.
2. Breakthrough message
If we, or others succeed in discovering intelligent life beyond our solar system, what – if anything – should we say to them? The international competition ‘Breakthrough Message’ [AR5] claims that it will encourage debate about how and what to communicate with possible intelligent beings beyond Earth. The challenge for competitors is to create messages that could be read by an advanced civilisation.
The message must be in digital format, and should be representative of humanity and planet Earth. As an extra incentive to your students, the total prize fund for best messages is $1,000,000. The competition is open to everyone. Why not start by holding an internal school competition to find the best entry for the international competition and then support a team of students to refine that message and submit an entry? Developing a message that could both speak for us and be understood by alien intelligences is a difficult problem and advice can be found from a number of sources on the internet including a recent article in The Guardian [AR6]. It may require insight in fields from mathematics and physics to linguistics, psychology and art. If this sounds like a daunting challenge tell your students about a comment made by scientist Dr Sandberg, who is part of a UK team entering the competition: “There’s a fair chance that we’ll get beaten by a schoolgirl somewhere, and in that case, more power to her!” [AR7]. Do you have the power?
SUMMARY
Closer to home
In this activity students explore the difference between intelligent life elsewhere in the galaxy and the captivating possibility that we may be able to discover evidence of primitive life much closer to home. Show students NASA’s recent announcement that liquid water exists on Mars at certain times of the year [AR8] including an animation of the seasonal flows in the Hale Crater. Scientists have reacted with the possibilities that this could mean for the current existence of microbial life on the planet, including the European Space Agency which plans a mission to investigate, ExoMars, leaving Earth as early as 2016 [AR9]. It is certain that such life, if it existed, would have to be adapted to live in extreme conditions.
Develop the cross-curricular link to biology by asking students to investigate extremophile survival. Divide the class into teams that can investigate the type of life that survives in high altitude on Mount Everest, searing temperatures in the desert, extreme heat and concentrations of dissolved salts in deep-sea vents, the mineral rich hot springs in Yellowstone National Park and the crushing darkness of the deepest place on Earth, the Mariana Trench. Each team can feedback in a presentation showcasing their organisms and how they are adapted to survive. In an extension or follow up activity you could carry out your own microscope investigation to find tardigrades. These incredible microscopic creatures (about 0.5mm in size) are easy to find and have survived exposure to outer space in temperatures close to absolute zero and a vacuum [AR10]. For instructions of how to find them, consult the UK microscopy website [AR11].
+KEY RESOURCE
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Learn Chemistry is the Royal Society of Chemistry’s award-winning website with over 3,900 free resources to help support you and inspire your students. Whether you want to make sure your lessons get off to the best start, encourage your students to grow in confidence, involve them more actively in their own learning or help them prepare for post-16 chemistry, Learn Chemistry has a free resource for you; and the helpful feedback from these computer-marked assessments will help advance your students’ learning and guide your teaching.
Explore the full range of free resources at http://rsc.li/resources
HOME LEARNING
Join SETI@home Give students the link [AR14] and ask them to join SETI@home on their home computers and become part of the search for extraterrestrial life in space.
STRETCH THEM FURTHERR
Pluto’s paradoxes
New Horizons is an incredible mission that is transmitting details of Pluto back from its recent fly-past of the distant dwarf planet. To put this into context for students play a NASA animation that shows our images of Pluto from its discovery until today [AR12]. Interesting features include blue skies, water ice, glacial shores and cliffs. All of these point to the possibility of internal tectonic forces at work. In this extension task, students investigate the features on the surface of the Earth caused by continental drift and the Earth’s internal geothermal energy supply. This is not dependent on solar energy and the vast majority of Earth’s geothermal energy is constantly generated by the decay of radioactive isotopes, such as potassium-40 and thorium-232. This process could also be alive and well on Pluto, and despite its vast distance from the sun it could have a lot in common with Yellowstone Park! Download high-resolution images of Pluto from NASA [AR13] and ask students to use Google Earth to identify similar geological features on Earth’s surface. The images of Pluto and their analysis is still at an early stage – if you find any exciting similarities why not share your research with NASA?
Make a Mars Rover
Have your students ever thought about how you could get around on Mars? If your school sent a rover to Mars, what would you want it to do? Climb to the top of the tallest mountain? Test a sample of soil to figure out what plants might grow? Find the best location to land humans on Mars? Use the resources provided by NASA to construct your own Mars Rover [AR15]
About the Author
Dr Joanna L. Rhodes M.Chem, D.Phil, MRSC is a teacher of science at Shelley College, Huddersfield.
