Professor Harrington was ready before students began to show up at her door. They slowly filed in and she smiled at each student hoping to remember their names soon. "Kia ora katoa, hello all," she said gaining the attention of the students. "So last week, I left off with a question, has anyone looked up the answer, as to why the stars move across the sky at night?" Sarah looked around the class asking her students. She saw one hand raised in the class and pointed to the student. "The Earth is spinning so they move like the Sun does," the student replied. "Yes! Exactly right, 5 points to you," Professor Harrington smiled at the student.
"We are spinning in a small circle around what is called an axis, like this globe I have here in the front of the room. We are also spinning in a large ellipse around the Sun. I'll define those words in a moment on the board," Sarah said noticing some of her students seemed confused by the words, probably on how to spell them she figured. "So standing on Earth we are actually traveling very very fast through space. Above us in the sky the stars appear to be fixed on giant sphere around us, this is called a celestial sphere," Professor Harrington paused for a moment in case she was beginning to talk to fast. "In truth stars are various distances from us but for now we will look up and talk about them as though they are all on this sphere around us. This sphere would look very similar to the bubble I placed around us last week, but with the other half. The Earth actually blocks our view at what is called the horizon, causing us to only see part of the celestial sphere."
"Now last week we saw the difference between 10pm and 3am on the same day. Tonight we are going to go up... right now actually! So you can see the sky at about 10pm today about mid November," Sarah said hurrying the students to go up the stairs to the observatory deck. Once there she began to speak again, "We talked about Vega and Vega was roughly to the northwest fairly close to the horizon." Professor Harrington pointed out to the spot on the horizon the students would expect to see the star. But the star wasn't there, in fact she waved her wand and a magical line connected dots and the constellation Pegasus was visible there again. "Two months ago we would have needed to stay up well past your bedtimes in order to see our friend Pegasus, but now at 10:14pm he is visible to us, this is because of that giant path the Earth is taking around the Sun. To sum up the star movements in the sky, the stars will rise and set daily, they will also shift slowly based on the time of year it is, or rather where we are on our path around the Sun, now back downstairs!"
"We ran out of time this week, so next week I'll have a list of words with their definitions that are important to us that you'll need to study. Once you've packed up you're free to go to your dorms or to come and ask me questions if needed," Professor Harrington said dismissing the class with a smile. She hoped they would be excited next week, for less lecturing and more looking at the nighttime sky. This week seemed boring even for her but they needed to know all this information.
*Kia ora katoa means Hello All in the Native New Zealand Language, Maori.
Please post with your student role playing the lesson!
First student to answer the question will be awarded the extra points.