1. Through the teaching of this course, students are required to know Cassiopeia and Orion. They will use Cassiopeia to find the North Star, knowing that the positions of Cassiopeia and Orion in the sky are constantly moving with time.
2. Cultivate students' observation ability-identify constellations and observe their movements.
3. Infiltrate the scientific view of nature-by observing the movement of constellations, let students realize that all celestial bodies in the universe are moving and changing.
Second, preparation before class
Teacher preparation: flip chart or slide-Cassiopeia and Polaris, Orion.
Student preparation: Observe the Big Dipper.
Third, the teaching process
Introduce a new course
1. Speak:
What season is it now?
(2) Which constellations have we observed in spring and summer?
(3) Last class, the teacher arranged for everyone to find the Big Dipper at night. Did you find it?
2. tell:
As we know, as the date goes on, the Big Dipper turns counterclockwise. In autumn night, the Big Dipper no longer hangs high at the zenith, but has turned to the horizon. At this time, it is more difficult to find the Big Dipper. So which constellation is more prominent in autumn? We will discuss this problem in this class.
Learn new lessons
1. Guide students to know the obvious constellations in autumn.
(1) Show wall charts or slides-Cassiopeia and Polaris.
(2) Description: On autumn night, at the zenith of the northern sky, there is a very obvious constellation similar to "M", called Cassiopeia. (blackboard writing "Cassiopeia")
(3) Observation: From the star map, how many stars does the M-shape of Cassiopeia consist of? Are these stars the same brightness? Which stars are brighter?
(4) Description: In ancient Greek mythology, this constellation was imagined as a fairy queen wearing a crown and sitting on a throne, so it was named Cassiopeia. It is very useful to know Cassiopeia, which can be used to find Polaris.
(5) Question: By observing the star map, can you see how to use Cassiopeia to find the North Star?
(6) Explanation: We mark five stars in Cassiopeia, which form an M-shape, and use 1, 2, 3, 4, 5 in turn to draw a line from the first star to the second star and extend it, and then draw a line from the fifth star to the fourth star and extend it, and the two lines have a little intersection; Draw a line segment from this intersection to the third star, and extend this line segment. At about five times the length of this line segment, you can see a brighter star, Polaris. Cassiopeia and the Big Dipper are opposite each other across the North Star. They go around the North Star like wheels. Cassiopeia hangs high at the zenith in autumn, and the Big Dipper hangs high at the zenith in spring. Cassiopeia is m-shaped at the zenith and w-shaped at the horizon.
(7) Exercise: Draw the relationship between Cassiopeia, Polaris and Big Dipper on paper, and the method of finding Polaris by using Big Dipper and Cassiopeia.
2. Guide students to know the meaningful constellations in winter.
(1) Explanation:
Next, the teacher will introduce you to a remarkable constellation in winter. (Show a map or slide of Orion. )
In winter, you can see a very striking constellation in the southern sky. In this constellation, four bright stars form an irregular quadrilateral, and there are three bright stars in the quadrilateral, which are arranged in a row obliquely.
In ancient Greek mythology, this constellation was imagined as a mighty hunter with a shield in his left hand, a big stick in his right hand and a sword hanging obliquely around his waist, so people called this constellation Orion. (Blackboard Orion) The four bright stars that make up a quadrilateral are located on the hunter's shoulders, left foot and right leg respectively, and the star on the left foot is white and bright. Three brighter stars are arranged horizontally at the hunter's waist, just like his belt.
(2) ask questions:
(1) In which season is Orion an important constellation? In which direction? (South or North? )
(2) What are the salient features of Orion?
③ Which stars in Orion are brighter? Which star is the brightest? What color is that?
(3) Practice:
Draw Orion on paper.
arrange work
1. Look for Cassiopeia in the northern sky at night, and use Cassiopeia to look for Polaris.
2. Observe and record: Will Cassiopeia's position in the sky change at different times of the day? Has the arrangement of the five stars changed? (record with a diagram. )
3. When winter comes (about 1 1 month later), look for Orion in the southern sky and see if its position in the sky has changed at different times of the day. Has the arrangement of the seven stars changed?