The document describes an educational exercise that uses simulations to help students understand how galaxy shapes form through interactions and collisions. Students will observe images of galaxies, then use a "Galaxy Crash" simulation to test different parameters and try to recreate the shapes. They will analyze the simulations to determine how long interactions take and what may happen to the galaxies in the future. The goal is for students to understand conceptually how galaxy morphologies arise and to think critically about astronomical observations and simulations.

1. CRASHING GALAXIES
(INQUIRY BASED TEACHING)
Tsourlidaki Eleftheria
Ellinogermaniki Agogi

2. GENERAL INFORMATION
• Brief Description: The following exercise aims to introduce to
students the concept of varying galactic morphologies. Students
will try to investigate the origin of the shapes of the galaxies that
stem from galaxy interactions.
• Connection to the curriculum:
Elementary education: Interdisciplinary courses, Astronomy:
Galaxies
Secondary education: Introduction to astronomy and space
physics, Gravity
• Age range: 9 – 11, 11 – 14, 14 – 16
• Time required: 2 didactic hours
• Technical Requirements:
Computers with internet connection and flash
Go-Lab platform
• Keywords: galaxy, elliptical, spiral, irregulars, lenticular, Hubble

3. GENERAL INFORMATION
Educational Objectives:
- Learn about the different shapes of galaxies.
- Get acquainted with making and studying astronomical
observations.
- Learn about simulations and how they may be used in a
scientific context.
Cognitive domain (processes): to think critically and creatively
Cognitive domain (knowledge): conceptual knowledge,
procedural knowledge
Affective domain: to respond and participate
Psychomotor domain: to adapt and perform creatively

4. QUESTIONS ELICITING ANSWERS :
EXHIBIT CURIOSITY
- What do these pictures depict?
- How are galaxies created?
- What would happen to our Galaxy if it
collided with another?

5. QUESTIONS ELICITING ANSWERS :
EXHIBIT CURIOSITY
During this exercise we will:
- Collect images of galaxies using a robotic
telescope
- Investigate the origin of the shape of the
galaxy we’ll observe using simulations.

6. QUESTIONS ELICITING ANSWERS :
DEFINE QUESTION FROM CURRENT KNOWLEDGE
- How are galaxies formulated?
- How many galaxies are there in the universe?
- What is a galaxy composed of?
-What is so special about the centre of galaxies?
-Why are galactic centres so bright?

7. ACTIVE INVESTIGATION : PROPOSE
PRELIMINARY EXPLANATION OR HYPOTHESIS
- How can we learn how these shapes came to be?
- How do you think these galaxies looked like before
they started interacting?
- What will happen to these galaxies in the future?
- How long does it take for a galaxy to be
formulated?

8. ACTIVE INVESTIGATION :
PLAN & CONDUCT SIMPLE INVESTIGATION
Choose some of the galaxies indicated and make
observations using the Faulkes telescopes.

9. ACTIVE INVESTIGATION : PLAN &
CONDUCT SIMPLE INVESTIGATION
NGC 4038 - The Antennae
12:01:52.68, -18:51:54.00
Coordinates:
Filter: Color
Exposure: 180 s
M51 and its companion, NGC 5195
Coordinates: 13:29:53.16, 47:11:48.120
Filter: Color
Exposure: 180 s

10. ACTIVE INVESTIGATION :
PLAN & CONDUCT SIMPLE INVESTIGATION
- We are now going to investigate the shapes of the
galaxies we observed.
How was their shape created?
How long did it take to be created?
What will happen in the future?
We are going to investigate the origin of these two
galaxies and answer the questions mentioned above
using a simulation. Just like astronomers do, we will try to
reproduce the observed image using a simulation, in order
to understand the process behind the shape of the
observed image.
•

11. ACTIVE INVESTIGATION :
PLAN & CONDUCT SIMPLE INVESTIGATION
- Go to the “Galaxy Crash” simulation
- Look at the galaxy in the image you have obtained from the
telescope and try to recreate its shape by using the simulator. In
order to do this, change the parameters in the panel and carry
out numerous simulations until you achieve the desired result.
- When the shape of the galaxy in the image resembles the
shape in the simulation stop the simulation and make a print-
screen. Insert your print screen in your notebook. If needed,
prior to making your print-screen, rotate and enlarge the image
in the simulation in order to make a more accurate match to
the real image.

12. ACTIVE INVESTIGATION :
PLAN & CONDUCT SIMPLE INVESTIGATION

13. DISCUSSION:
EXPLANATION BASED ON EVIDENCE
- Explain which parameters you used for your best model in the
simulations you have carried out.
- How long did it take for this interaction to reach the observed
stage?
- Based on your simulation, describe how the current shape of the
galaxy has been formed.
- Based on your simulation, what do you think will happen to these
galaxies in the future?
- What happens to the relative velocities of the galaxies as they
reach their point of closest approach (perigalacticon, or peri for
short)?

14. DISCUSSION:
CONSIDER OTHER EXPLANATIONS
- Do your team’s parameter match the parameters
chosen by other teams?
- Could there be any other different way to form the
same galaxy?
- Do you conclusions much your initial predictions?

15. REFLECTION:
COMMUNICATE EXPLANATION
- What parameters are involved in the shaping of
galaxies?
- Why are spiral galaxies more active in terms of
star formation?
- How long does it take for a galaxy to form?
What kind of galaxy is the Milky Way?