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NASA Ames Research Center

Using Kepler LEGO Orreries in a College Astronomy Lab

An Interview with Doug Duncan conducted 2008 August 27 by Dawn Robles


Doug Duncan with LEGO orrery
Doug Duncan with LEGO orrery at University of Colorado Astronomy Lab.

Doug Duncan is a faculty member in the department of astrophysical and planetary sciences at the University of Colorado-Boulder, and director of the Fiske Planetarium. He has used the Lego Orrery in his introductory astronomy courses for non-science majors to teach about the transit method. Duncan found out about the orrery at an American Astronomy Society conference in 2006; it was on display in a booth hosted by Alan Gould. Duncan downloaded instructions and had several models built. At the time of this interview, Duncan was not involved with any other aspects of the NASA-funded Education and Outreach efforts of the Kepler mission.

Why did you decide to use it?

I am pretty familiar with assessment and know a lot about how people learn… so when I saw a wonderfully imaginative and simple-to-use Lego orrery I instantly thought ‘that could improve the learning of my college students.’

What is your purpose or goal of using the orrery?

LEGO orrery college lab setup
LEGO orrery college lab setup

I know from experience that many labs are quantitative and pretty cookbook style – I find that it is quite possible for students to follow instructions in a typical beginning college lab but not to really learn the concepts. So I am always looking for ways for them to do experiments that are more qualitative; it’s not so much about the numbers, it’s about the concepts. So when it comes to something like the Kepler mission, it is nice that that method of planet detection is concrete – students can easily visualize a dip of light when something moves in front of something else, as compared with Doppler detection of planets. But I really like the Lego orrery -- the technology was simple enough that students would not be distracted by the technology.

How do you use it?

LEGO orrery in University of Colorado Astronomy Lab
LEGO orrery in University of Colorado Astronomy Lab

I divide the class into two teams – we have two orreries and so the numbers are manageable. Each team has 4 students. I take a big piece of cardboard and I hide the orrery from one set of four, and the other set of four gets to work with it. The four who can’t see what is going on with the orrery are called the observers; the others who work with the orrery are called the creators. The orrery I give them does not have planets on each of the three arms yet. I give the creators little Styrofoam balls, clay, and aluminum foil – I tell them ‘you are god, you make a solar system,’ and they love that. It is up to them to choose which planets of the three are big or small. Then once they have made the solar system and they turn it on, the observers get to see the traces and the dips. The challenge to the observers is to describe the unseen solar system. It has a lot of human interest when done this way; they are curious about what is there and what their friends are doing. Then once they make their hypothesis about what the solar system looks like, we take down the cardboard, and we let them see and then of course we swap. It delighted me that I have students be so creative that they take a toothpick and attach a moon, and make a planet with rings using clay. That makes for a complicated enough tracing during the transit that the other side could not figure it out what it was. But they sort of had a sense that something was weird. Remember that these are non-science majors; they’re typically freshmen, and this is their first science class. So we don’t spend a lot of time expanding the trace and looking at it in slow motion or finer detail like a more advanced scientist would do. I think if you were to add multiple orbits or if you were to decrease the data-taking rate or something a little more sophisticated you would get the depth to show you a few more details. They are not sophisticated enough to do that but they are absolutely sophisticated enough and motivated enough to be very creative when they make the solar system. They want to make this challenging: ‘how can we fool the other team?’

What do you like about the orrery?

LEGO orrery at CU
LEGO orrery at CU

There are many things that are positive about the Lego orrery. First of all, once the students marvel at the fact that it is made of Legos, then they can concentrate on what’s happening rather than the gizmo itself. At the same time, it’s important for them to know that science happens in everyday life, not just in the science lab, so it’s another plus that it is built out of everyday materials.

Another point, and maybe the biggest, is that few labs get to this level of success. What I love about the way that I have been able to use the orrery is that it is an open-ended, inquiry-based lab that invites creativity… it allows them to do something sort of cool, that’s concrete enough that they can visualize it and have success and its purely qualitative; it’s all about the concepts.

Do you have ideas about other possible ways to use it?

LEGO orrery at CU

We have a large planetarium that seats 220 – it also has a lobby with some science exhibits. One of my future projects is to put an orrery into this unstructured space so students and the public could wander in and out; I think that would be quite fun. It would have to be made stronger and more robust to be put out on an exhibit floor.

Probably just this conversation is going to motivate me to talk to the person who is teaching the solar system this fall and say, ‘hey I tried this experimental orrery lab and it was fantastic;’ and ask him if he is interested in substituting it for one of the old fashioned labs.

Are there any issues or problems with the model?

Aiming the light sensor at the model star of the LEGO orrery
Aiming the light sensor at the model star of the LEGO orrery

The only real problem we have had in the lab is parts falling off the orrery… it’s easy to fix – you just put them back on… it’s probably a problem because when we first built the two I couldn’t decide whether to glue them or not – I didn’t have the courage if it didn’t work we could never get the orrery apart. Because of that we made the choice not to glue them and that was probably wrong. It happens during student use. They are a little rougher with it than we are. If the teaching assistant or the lab manager is not available the activity comes to a halt until they are. In our case I have asked our lab manager to rebuilt it and glue it. Alan has a version out of wood that looks more robust. But for non-science majors, I want to show students that science is all around you and in everyday life. So I like that this is made of LEGOs.

Do you see any evidence of orrery helping students better understand the solar system?

Divider separates lab teams; one team cannot see the LEGO orrery, only the light curve
Divider separates lab teams; one team cannot see the LEGO orrery, only the light curve.

I would love to say yes, but the true answer is no. We had a standard syllabus of cookbook labs; yet again the bureaucracy gets in the way. I am one of the newer faculty members in this department and in order to make this an official lab it would probably have to replace one of the previous labs that was official and done by someone senior to me. So I was encouraged to do this as an experimental lab.

[The orrery activity/lab] certainly gives the students an example of scientific inquiry that they can actually do and the enthusiasm they display is completely obvious. In the affective domain it clearly was one of the most popular things about all the labs. I’ve personally seen enough students use to know that.

…Ironically I do have assessment data on the old labs that proves they don’t work. That is because they are more complicated in execution so students spend most their brainpower learning how to do the lab, and they can explain that to you beautifully. But when you ask them, ‘ok, what did it teach you?’ they are at a loss. I believe that really good educational technology should be as transparent and easy to use as possible.

Are there accompanying materials/activities?

Students like the open ended nature of the lab
Students like the open ended nature of the lab.

It’s a little embarrassing but I simply told my learning and teaching assistants to explain to the students how it works. They all stand around and look at it, and the assistants explain: ‘This is the apparatus; you see when the little arm goes around the light dips down. This is how we hope to detect planets with the Kepler mission. You’re just going to break into two teams and do it.’ It’s not even written up… but when we do write it down we will have to be careful to not say too much. I think it would be a typical but poor idea to say, for example: ‘you may want to try different sizes of planets, etc…’ because the students really appreciate that they are allowed to be creative.

What suggestions do you have for improving it?

Not much! It would be good to post, on the Kepler website where the orrery is, something that says ‘some astronomers are using this in the formal setting; they are using this as a lab,’ and then give a basic description. Try to get more people to do this - you have a valuable resource and it might as well spread.