If you missed it, you can check part 1 and part 2:
This post is part of a wider teaching project. We engage physics (basics of sound part 1 and part 2) and astronomy (facts about the moon). The main goal is to get young (and why not older) learners involved in a fun and easy-to-digest learning process.
Now, in case you don't remember my trolls set off on a new adventure with their little DIY rocket. Their destination was the moon. There X31, the wise troll, explained that we can't hear on the moon because the atmosphere is too weak to support the propagation of sound waves (part 1) and then he gave us some details on its composition (part 2). In the last episode we left X42 lifting a big rock very easily. Let's follow the troll-team to see why this happened...
- He didn’t get stronger, X54, X31 said, it’s gravity. The earth is a lot bigger than the moon, this means that the force of gravity is greater on earth. We all weigh less up here, almost one sixth of how much we weigh back home.
- Really?
- Yes, that’s why I wouldn’t advise you to jump too high as you might get tossed away into space. You see, gravity is the force that pulls an object towards another and it’s proportionate with the mass of the two objects. Since the mass of the moon is a lot less than the mass of the earth, then gravity is also less up here and the force that keeps us on the moon’s surface is significantly weaker.
- Ha! Now I can eat as much as I want and not worry that I might get fat, cause I am actually lighter on the moon! X54 said happily.
- If only it worked that way, X54, X42 spoiled X54's joy.
- Do you want to know some more interesting facts about the moon?
- Yes, X31! Please, tell us some more! both trolls shouted excitedly.
- Do you know that people falsely believe that there is a dark side of the moon?
- Everyone has their dark side, why not the moon, X31? X42 said.
- I didn’t mean it that way, X42. From the earth we can always see the same side of the moon due the perfect timing of its rotation around its axis and orbit of the earth. Although the sun gets to see the whole of it, people need to get in a spacecraft to see the back of the moon.
- Maybe it looks better from this side and that’s why it shows us only this, said X54.
- Who knows, X54? Also, did you know that the moon is slowly drifting away from us?
- Like trying to escape? X42 wondered.
- Sort of. Every year its orbit gains 3.8 cm. If this continues for another 50 billion years, the period of one orbit around the earth will get from 27.3 to 47 days.
- Are we gonna have to change our calendars too?
- I don’t know, X42, I doubt we’ll be around to see that after so many years.
- Right.
Suddenly the ground starts shaking and the trolls get scared.
- What’s happening!? X54 sounded terrified.
- Guys, be careful! X42 shouted.
- Get on the rocket! Let’s leave this place or the moonquake will toss us out into space.
- All aboard! Troll team, we’re outta here!
To be continued
References
earthobservatory.nasa.gov
van.physics.illinois.edu
theplanets.org
*All images by @ruth-girl - Original background images of the moon surface from: pixabay.com (CC0 - no attribution required)
Thank you for stopping by and giving this post a read. I hope you enjoyed it! If you please, feel free to pay a visit to my blog and check out my short stories along with plenty of educational posts and of course my bizarre natural phenomena series.
Until my next post,
Steem on and keep smiling, people!
