Tag: astronomy

Astronomy Labs

When I worked as a Science Education Specialist in the Department of Physics & Astronomy at UBC with the Carl Wieman Science Education Initiative, I had the opportunity to create lab activities for the survey astronomy courses (aka “Astro 101”). These are courses aimed at students outside the Faculty of Science who need some science credits to graduate. One course was about the Solar System; the other is about stars and galaxies.

With the support of the CWSEI, I worked with some terrific course instructors to first write learning outcomes for each course. We then identified the outcomes that would be better supported by hands-on learning in the labs. For example, it’s well known students struggle to learn about the phases of the Moon by listening to the professor and looking at diagrams in a traditional lecture, whereas in a hands-on lab setting, students would be better able to

  1. use the geometry of the Earth, Moon, and Sun to illustrate the phases of the Moon and to predict rise/set times
  2. illustrate the geometry of the Sun, Earth, and Moon during lunar and solar eclipses and explain why there are not eclipses every month

I aimed to develop activities that gave students opportunities to practice thinking and acting in more expert-like ways, rather than replicating and confirming known results. So, some of these activities are a bit unusual, like figuring out the best night of the month to sneak across campus or spaghettifying a Playdoh astronaut as he falls into a blackhole.

Format and Files

All the activities have a similar format:

  • The activities are designed to be completed in 50 minutes by 20-30 students in a basic lab environment (large tables to support teamwork and collaboration, some specialized equipment, space for students and TAs to circulate). They’re classified as “tutorials” because they’re only 50 minutes long, rather than 3-hour “labs”.
  • Each activity has a brief intro that motivates the outcomes, one or more active, hands-on, discovery phase(s), and ends with a short assessment the students hand in on their way out the door.
  • The activities are facilitated by 1 (or sometimes 2) trained and engaged Teaching Assistants and that required us to write guides for the TAs. It’s well known that “recipe” labs are less effective: students are able to follow a detailed set of instructions but often are unable to transfer what they verify to other contexts. We learned quickly that providing TAs with a recipe for running the activity (“1. Do A. 2. Get students to do B. 3. Do C….”) did not engage the TAs, gave them no opportunity to learn about teaching, and provided minimal professional development for those looking ahead to academic careers. So, I revised the TA Guides so they identify the required equipment and steps and also give recommended questions and scripts to drive the discussions and explanations for the pedagogical choices.
  • The files linked here include PDFs of the materials handed out to students, the TA Guide, and a .zip file with LaTeX, .eps graphics, and any other supporting materials. The LaTeX files use several packages including pstricks. Overleaf has no problem compiling the files when you select xelatex instead of pdflatex.

Attribution

You’re welcome to copy, borrow, and adapt to fit your context and outcomes. If there’s an opportunity to add some attribution, you can write

Unless other wise noted, resources are shared under a Creative Commons Attribution 4.0 International (CC-BY) license by Peter Newbury peternewbury.org. This work is supported by the Carl Wieman Science Education Initiative at the University of British Columbia.

 

When a meteorite hits the surface of a planet or moon, it creates an impact crater. This picture of our Moon’s Mare Nubium and surrounding hills shows some of the Moon’s surface is quite smooth while other regions are covered in craters. By measuring the sizes and number of craters, astronomers can learn about the objects (called the “impactors”) that struck the surface and also about the ages of various regions on the planet’s surface.
An orrery is a mechanical model of the Solar System. When you turn a crank, the planets and moons orbit the Sun at correctly-scaled distances with correctly-scaled periods. In this tutorial, you and your classmates build a scale model of the Solar System by marking the locations of the visible planets, Mercury, Venus, Earth, Mars, Jupiter and Saturn, at regular intervals of time. Later, when you and your classmates step from location to location, you’ll reproduce the motion of the planets – a human orrery!
Every month, the Moon appears to change shape in the sky as it goes through phases from new Moon to full Moon and then back to new. Ancient civilizations used the phases of the Moon to track the passage of time. Today's Gregorian calendar no longer depends on the phases of the Moon but the Islamic, Hebrew and Chinese cultures still base festivals and holy days on the cycles of the Moon.

The more you understand the nature of the Moon's phases, the more you can appreciate how astronomy influences our culture and the better you'll be able to predict when important events like Ramadan, Hannukah, Easter and Lunar New Year will occur.

In this tutorial, you will explore the changing geometry of the Sun-Earth-Moon system that produces each phase of the Moon, and then the connection between the geometry and the time of day the Moon rises and sets.

Madden et al. (2020) use an adaptation of this activity in an interesting astronomy education research project that compares students' learning and experiences using VR, a desktop computer simulation, and this hands-on analog activity.
The Sun, stars and planets cross our sky in complicated patterns that depend on the Earth’s daily rotation around its tilted axis and its annual revolution of the Earth around the Sun. For thousands of years, astronomers have watched the sky, figured out the patterns and built “computers” so they could predict when and where the Sun, stars and planets rise and set each day. In this tutorial, you’ll use your 21st Century computer to explore the motion of the Sun.

 

Note: this activity was built using the NAAP Motions of the Sky Simulator which doesn't function any more. You can easily adapt the activity to a simulation that shows the path of the Sun across the sky.

(Credit: NASA/Tim Pyle)
Astronomers have discovered hundreds of planets orbiting other stars. These planets are in solar systems beyond ours so they are called “extrasolar” planets. A growing number extrasolar planets are found by the transit method. In the transit method, astronomers take precise, long term observations of the brightness (or “intensity”) of a star and create a light curve for the star. In this tutorial, you’ll explore the connections between light curves and extrasolar planets and learn how to decode the light curve. Then you’ll examine the light curve of a real star and discover the characteristics of the planet HD 209458b, the first transiting extrasolar planet ever found.

(Credit: Robert Gendler)
Stars are the building blocks of the Universe – there are billions of stars in our Galaxy and billions of galaxies in the Universe. To understand how the Universe works, we need to understand how stars work. In this tutorial, you'll create a concept map to organize the content, reveal relationships and patterns, and make the content easier to recall later.
(Image credit: : Mt. Wilson Archive, Carnegie Institution of Washington)
Since the Big Bang nearly 14 billion years ago, the Universe has been expanding. We know that because we’re watching other galaxies follow a curious pattern: the farther away the galaxy, the faster it is moving away from us. This discovery, made by Hubble in 1929, is known as the Hubble Law. The Hubble Law comes with an optical illusion: it looks like we’re at the center of the Universe. Are we really that special? In this Tutorial, you’ll clear up this illusion.
In this activity, students investigate the quantities that determine the strength of the force of gravity between two objects, identifying what matters and how that quantity changes the force. So they can recognize and appreciate the inverse-square law of gravity, the students first play with an analogy: the amount of pain the cartoon character Fry feels when he looks are different sized light bulbs, from near and far and with open or squinting eyes. They do this through an “invention activity” (Schwartz and Martin, 2004) which are proven to increase students’ understanding of the new concept (gravity) and their ability to transfer that knowledge to other situations.
Look at the desk and look around the room. Seems pretty flat, doesn’t it? But the Earth isn’t flat, so why is the room? What about the Universe? Is it flat? Does it have positive curvature? Negative? How can we tell? In this activity, you’ll do experiments that explore the effects of curvature. The key to determining the shape is the number of degrees in a triangle.
White dwarfs and neutron stars are two bizarre forms of stellar corpses left behind after the star collapses. For a very massive star, though, nothing can stop its end-of-life collapse. The star becomes a black hole, one of the strangest and most extreme objects in the Universe. How extreme? Spacetime is so curved (or as Newton would say, “gravity is so strong”) not even light can escape once it falls into a black hole. What would happen to a star or a planet that gets too close to the black hole? In this tutorial, you’ll figure that out by watching a poor astronaut fall into the black hole of death!
The colour of a glowing gas, like a candle flame, the burner on a gas stove, or a star reveals its temperature: hotter gases glow blue, colder gases glow red. On more careful inspection, though, the light we receive from each gas contains an enormous amount of information: not just its temperature but also its chemical composition, motion and more. This information is found by decoding the spectrum of the gas. In this tutorial, you’ll learn how to “crack the code” and reveal what the glowing objects are made of.
Stars come in all colours and sizes, masses and brightnesses, ages, and distances. How can we possibly learn how stars work when each one appears to be unique? What we need are some relationships between the characteristics of stars. We already know that the colour of a star is directly related to the temperature of the star: red stars are cool, blue stars are hot. That means we don’t have to measure both colour and temperature – we get one from the other. Are there any other relationships? What does a “relationship” look like, anyway? And what does a relationship tell us about how stars work? In this tutorial, you’ll see what it means for characteristics to be related (or not related) and then see how to use the relationships.  

You don’t have to wait for the clock to strike to start teaching

In the astronomy education community, it’s almost universal that we come into the classroom and, as quickly as possible, get a browser on the screen showing Astronomy Picture of the Day. As the students find their seats and settle, they can’t help but glance up at the picture. It gets them into “astronomy mode.” More often than not, the instructor can find some connection between each day’s APOD and the class’ content. We can begin each day with a conversation about astronomy.

Recently, I’ve been visiting classes of first-time instructors. Many times, the students arrive, find their seats, stare momentarily at the blank screen, and launch into some conversation with their neighbors. And not one about astronomy or chemistry or history or whatever they’re going to be doing for the next 50 or 80 minutes.

That’s an opportunity lost.

Instructors, your students are here, ready to turn their attention to your material. Grab their fleeting curiosity and exploit it! Find a picture or diagram or something interesting, maybe even from later in today’s class, and put it on the screen. And then do this:

Add two lines of text:

What do you notice?
What do you wonder?

Can there be better prompts for starting a conversation with your students? EVERY student can notice something and wonder about it. This is another opportunity for you to

  • give your students practice interpreting graphs/diagrams/photographs
  • give them practice talking about your field
  • create an opportunity for your students to contribute to the class, rather than being spectators
  • learn what your students are thinking about — that’s critical if you want to build new knowledge on existing knowledge (you know, How People Learn…)

For example…

I know N=1 isn’t data so let me call this a case study about how a simple picture with those “notice” and “wonder” prompts reveals wonderful things about your students. I was in a meeting with half a dozen grad students, from all across campus, and I put up this slide:

sunset_whatdoyounoticewonder_peternewbury_ccWithin 30 seconds of me saying, “Well?”, they’d taught each other that this was a sunset. It went something like this:

There’s a half a Sun.
So it’s sunrise or sunset.
Dude, we’re in San Diego. The only place you see a horizon like that is West. This is a sunset.

Get. Outta. Here! Do you know how much context and personal experience and astronomical knowledge was revealed there! And I didn’t say a word of it!

So, do it! Find an interesting picture and make it your first slide. When you get to class, get it on-screen as quickly as possible, before you straighten your notes and pull last week’s homework from your bag and get the microphone cord threaded through your shirt and talk to that student about that thing and…

You don’t have to wait for the clock to strike before you start teaching.

Credit where it’s due

Big tip-of-my-hat to Fawn Nguyen who, through this post, introduced me to Annie Fetter at The Math Forum @ Drexel. Got 5 minutes? Watch this:

 

A Tale of Two Comets: Evidence-Based Teaching in Action

Comet McNaught
Comet McNaught wow'd observers in the Southern Hemisphere in 2007. (Image by chrs_snll on flickr CC)

We often hear about “evidence-based teaching and learning.” In fact, it’s a pillar of the approach to course development and transformation that we follow in the Carl Wieman Science Education Initiative.

It’s a daunting phrase, though, “evidence-based teaching and learning.” It sounds like I have to find original research in a peer-reviewed article, read and assimilate the academic prose, and find a way to apply that in my classroom. Does a typical university instructor have the time or motivation? Not likely.

It doesn’t have to be like that, though. There are quicker, easier analyses and subsequent modifications of materials that, in my opinion, qualify as evidence-based teaching. Let me share with you an example from an introductory, general-ed “Astro 101” astronomy course. First, a bit of astronomy.

Comets and their tails

Comets are dusty snowballs of water ice and other material left over from the formation of the Solar System. The comets we celebrate, like Comet Halley, travel along highly-elongated, elliptical orbits that extend from the hot, intense region near the Sun to the cold, outer-regions of the Solar System.

Comet's tail
A comet's tails point away from the Sun. The comet is orbiting clockwise in this diagram so the yellow dust tail trails slightly behind the blue ion tail.

As comets approach the Sun, like Comet Halley does every 76 years, the comet’s nucleus warms up. The ice turns to gas which creates a sometimes-spectacular tail. The tail grows larger and larger, streaming out behind the comet until it rounds the Sun and begins to head back out into the Solar System. That’s when something interesting happens. Well, another interesting thing, that is. You may think the comet’s tail streams out behind like the exhaust trail (the contrail) of an airplane but once the comet rounds the Sun, the tail swings around ahead of the comet. Yes, the nucleus follows the tail. That’s because the tail is blown outward by the solar wind so that the tail of a comet always points away from the Sun. (Well, there are actually 2 tails. The ion tail is strongly influenced by the solar wind – it’s the one blown directly away from the Sun. A dust trail also interacts gravitationally with the Sun, causing it to curl out behind the ion tail.)

Teaching and learning

It’s not what you’d expect, the tail wagging the dog. And that’s make it a great opportunity for peer instruction and follow-up summative assessment.

Last December, the course’s instructor and I sat down to write the final exam. We could have used a multiple-choice question

The ion tail of a comet always…
A) points away from the Sun
B) trails behind the comet
C) D) E) [other distractors]

Or perhaps a more graphical version, like this one from the ClassAction collection of concept questions:

Comet Trajectories concept question from ClassAction
A concept question about the shape of a comet's tail from the ClassAction collection at the University of Nebraska - Lincoln. The correct answer is C, by the way.

Both of these questions are highly-susceptible to success-by-recognition where the student doesn’t really know the answer until s/he recognizes it in the options. “What do comets’ tails do again? Oh right, they point away from the Sun.”

Instead, we decided on a question that better assessed their grasp of how comet tails behave. The cost is, this question is more difficult to mark:

Assessment

Oh, the question was marked out of 2, 1 pt for each tail pointing away from the Sun. That’s not the kind of assessment I mean, though. I’m talking about the assessment that goes into evidence-based teaching and learning. How did the students respond to this question? What it a good test of their understanding?

I went through the stack of N=63 exams and sorted them into categories. It wasn’t hard to come up with those categories, it was pretty obvious after the first 10 papers.

  • 46 students: tails of equal lengths pointing away from the Sun. Yep, 2 out of 2.
  • 5 students: tails of equal lengths pointing away from the Sun with guidelines. Nice touch, reinforcing why you drew the tails the way you did. 2 out of 2. And some good karma in case you need the benefit of the doubt later on the exam.
  • 3 students: drew ion tail correctly and dust tail mostly correct. Good karma for adding extra detail, though the dust trail is too much traily-behindy. Be careful, kids, when you write more than is asked for – you could lose marks.
  • 1 student: tails with (correctly) unequal lengths pointing away from the Sun. Oh, very good! Maybe 3 out of 2 for this answer!
  • 8 students: various incorrect answers. I like this first one (“Oh, geez, there’s something about pointing and the Sun, isn’t there? Ummm…”)

Evidence-based teaching

It’s clear that the vast majority of students grasp the concept that a comet’s tail points away from the Sun. Terrific!

So why are we wasting this question on such an obvious bit information, then? Let me put that another way:  These students are evidently, and I mean evidently, capable of learning more about comets. We thought this <ghost> “Oooooo, watch oouuttt! Comet tails point awaaaaayyyy from the Suuuun…” </ghost> concept would be difficult enough. Nope, yhey surprised us. So let’s crank it up next year. Let’s explore the difference between the ion and dust tails. And that the length of the tail changes as the comet approaches and recedes from the Sun. Next year, the answer that gets full marks will be the one with

  • 2 tails at each position,
  • the ion tail pointing away from the Sun,
  • the dust tail lagging slightly behind the ion tail,
  • short tails at the far location, large tails at the close location

That’s evidence-based teaching and learning. Find out what they know and then react by building on it and leveraging it to explore the concept deeper (or shallower, depending on the evidence.) It’s not difficult. It doesn’t require poring over Tables of Contents, even in the excellent Astronomy Education Review. All it requires is small amount of data collection, analysis and ability to use the information. Hey, those are all qualities of a good scientist, aren’t they?

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