Investigation Driving Question

How can we determine if a newly discovered asteroid is a threat to Earth?

Storylines

The storyline process is intended to be student-driven and connect lessons within the unit. The Hazardous Asteroids investigation, including this phenomenon, would fit best into unit storylines that deal with:

• Natural Hazards
• Physics of orbits
• Evolution of the Solar System
• Solar System composition

Instructions for Introducing Phenomenon

1. Before class starts, arrange a Driving Question Board (DQB) so it is visible to all students. This can be created using sticky notes or in a digital format (see other resources here). The DQB should include the investigation driving question, “How can we determine if a newly discovered asteroid is a threat to Earth?” Students will be revisiting this DQB throughout the lesson to expand upon their original thoughts and ask questions to better explain the supporting phenomenon. If you have a driving question for the unit or already created a DQB board, this investigation driving question can be used as a sub-question.
   
2. Show the first 2 minutes, 38 seconds of this ABC News video of the Chelyabinsk meteor entry and impact in 2013. (Note- there is an ad at the start of this video).
   
3. Facilitate a discussion with students so they can share what they noticed/thought about the content of this video. Students will likely bring up ideas ranging from “I didn’t think this kind of thing really (still) happened” to “why didn’t we know it was coming?” Be prepared to offer acknowledgment and support if some students find the idea of an asteroid impact disturbing. Suggest that the investigation will go further to address the ideas they have raised.
   
4. Then offer this scenario: “Astronomers have determined a newly-discovered asteroid is on a crash course to hit Earth. You are a member of the team assigned to predict if this asteroid will cause damage when it enters Earth’s atmosphere, and if so, how much damage it might cause. Discuss with your teammates what you need to know about the asteroid in order to determine if it may strike Earth, and the range of its potential damage.”
   
5. Continue to facilitate the discussion with the remaining Leading Questions below, as desired. For some of the questions below, possible answers are listed in parentheses. Do not read these to the students. They are listed for you to develop as prompts in case the discussion stalls.

Leading Questions

• What do you need to know about the asteroid in order to determine its potential damage? (size, mass, density or composition, speed of travel, the angle at which it moves through the atmosphere, at which location it will strike Earth).

• Sometimes asteroids (like the Chelyabinsk asteroid) break into pieces as they move through the atmosphere. Does breaking into pieces make an asteroid more or less dangerous?

• If the asteroid lands in the ocean, would that make it less dangerous? (consider how close it comes to a shoreline, and the depth of the water. It may cause flooding, or a tsunami.)

• If you discovered that this meteor was not going to hit Earth until 90 years in the future, would that change how you felt about its potential damage? Why or why not?

After the Investigation - Making Sense of the Phenomenon

1. Hold a class discussion as students look back at the remaining questions on the DQB. What questions can we answer? What additional questions do you have? Encourage students to independently investigate any remaining questions they have.
   
2. Ask students follow-up questions to make sense of the Phenomenon and apply their understanding in a new way:
   1. What factors make it difficult to detect potentially hazardous asteroids? (possible answers: they are small, dim, close to the Sun in the sky and therefore hard to observe, their orbits may initially be hard to predict and may require multiple observations to refine, the frequency at which we can observe the same area of the sky in order to detect them).
   2. Should we increase the resources currently allocated to discovering potentially hazardous asteroids? Why or why not?
   3. Based on the properties of the known potentially hazardous asteroids, what mitigation strategies should we focus on?