The Constellations in Astronomy - Grade 9 .pptx

About the constellations

1. CONSTELLATIONS

2. Learning Objectives Identify and describe different constellations. Differentiate seasonal and circumpolar constellations. Appreciate the importance of constellations in navigation, culture, and astronomy.

3. Have you ever looked at the night sky and noticed patterns of stars? What do you think they are?

4. A constellation is a group of stars in the sky that forms a pattern and has a name. For example, the stars on the right are nicknamed the Big Dipper because they look like a ladle! CONSTELLATIONS

5. Ancient civilizations used constellations for navigation, calendars, and mythology.   Modern astronomy recognizes 88 official constellations that divide the sky into regions. CONSTELLATIONS

6. TYPES OF CONSTELLATIONS 1. Seasonal Constellations These constellations are visible only during certain times of the year. Their visibility changes due to Earth's revolution around the Sun. Because Earth orbits the Sun, the position of stars changes throughout the year. This is why we can only see certain constellations during particular months .

7. TYPES OF CONSTELLATIONS Examples: Orion ( The Hunter ) – visible in winter, known for Orion’s Belt. Leo ( The Lion ) – visible in spring, represents the lion of Greek mythology. Scorpius ( The Scorpion ) – visible in summer, linked to the myth of Orion. Pegasus ( The Winged Horse ) – visible in autumn, associated with Greek myths

8. ORION

9. LEO

10. SCORPIUS

11. PEGASUS

12. TYPES OF CONSTELLATIONS 2. Circumpolar Constellations These constellations are visible all year long because they are near the celestial poles.   They appear to rotate around the North or South Pole due to Earth’s rotation. Circumpolar constellations are always visible in the night sky for certain latitudes, particularly in the northern hemisphere.

13. TYPES OF CONSTELLATIONS Examples: Ursa Major ( The Great Bear ) – contains the Big Dipper, a useful navigation tool. Ursa Minor ( The Little Bear ) – contains Polaris, the North Star. Cassiopeia ( The Queen ) – recognizable by its "W" shape. Draco ( The Dragon ) – a long, winding constellation in the northern sky.

14. URSA MAJOR

15. URSA MINOR

16. CASSIOPEIA

17. DRACO

18. IMPORTANT CONSTELLATIONS Orion One of the most famous and easily recognized constellations. It is known for the three stars that form the "belt" of Orion, representing a hunter in Greek mythology. Ursa Major (Big Dipper) A circumpolar constellation visible throughout the year in the northern hemisphere. The Big Dipper is part of Ursa Major and is used to find the North Star (Polaris).

19. Importance of Constellations Navigation Sailors and travelers used constellations like the North Star (Polaris) to find directions. Timekeeping Early civilizations tracked seasons for farming using constellations. Culture & Mythology Many constellations have stories from Greek, Chinese, and other mythologies.

20. Modern Use of Constellations In modern astronomy, constellations help astronomers locate stars and other celestial objects. The International Astronomical Union (IAU) officially recognizes 88 constellations , which are used as a way to divide the sky into manageable sections for study. Today, constellations still serve as a way to locate stars, planets, and galaxies in the night sky. Modern astronomers use the IAU's system to map the stars and track the movement of celestial bodies.

21. Why Do Constellations Seem to Move?   Earth's Rotation Stars appear to move from east to west because Earth rotates on its axis. Earth's Revolution Different constellations are visible in different seasons due to Earth’s orbit around the Sun.

22. The Earth rotates on its axis once every 24 hours, which is why our day/night cycle is 24 hours long. Earth's rotation impacts how we view constellations. EARTH'S ROTATION

23. As the Earth rotates, your position on Earth changes relative to the stars. This phenomenon, known as diurnal motion , makes it appear as though the constellations move across the sky throughout the night, just like the Sun 'moves' from East to West each day. DIURNAL MOTION E W

24. THE VIEW FROM EARTH E W 6:oo PM 12:0o AM 6:0o AM

25. Just as the Moon orbits the Earth, the Earth orbits the Sun. It takes the Earth around 365 days to orbit the Sun, which is why our calendar year is 365 days long. Earth's orbit also affects how we view constellations. EARTH'S ORBIT

26. Throughout the year, constellations gradually shift West due to Earth's revolution around the Sun. This is called annual motion . Since the Earth faces a different direction each season, some constellations are only visible during certain times of the year. ANNUAL MOTION Pisces Aquarius Capricorn Sagittarius Scorpio Libra Virgo Leo Cancer Gemini Taurus Aries

27. One set of constellations visible along Earth's elliptical orbit belongs to the zodiac . These constellations are the foundation for zodiac signs and astrology. THE ZODIAC Pisces Aquarius Capricorn Sagittarius Scorpio Libra Virgo Leo Cancer Gemini Taurus Aries

28. Pisces Aquarius Capricorn Sagittarius Scorpio Libra Virgo Leo Cancer Gemini Taurus Aries The months that correspond to each zodiac are based on the Sun's position relative to the zodiac constellations. For instance, the Sun faces the constellation Aries in April, so people born in (most of) April are of the Aries astrological sign. THE ZODIAC

29. EAST WEST 1:0o AM What will be the approximate position of the constellation in five hours? CHECK FOR UNDERSTANDING #1 A B D C

30. EAST WEST 1:0o AM The constellation will be in position D (approximately) after five hours because constellations appear to move from East to West in a 24 hour cycle. CHECK FOR UNDERSTANDING #1 D 6:0o AM

31. Which zodiac constellation is the sun 'in' on the diagram to the right and, given that the Sun is in Aries for most of April, what month is it on Earth? CHECK FOR UNDERSTANDING #2 Pisces Aquarius Capricorn Sagittarius Scorpio Libra Virgo Leo Cancer Gemini Taurus Aries

32. The Sun is facing Sagittarius in the diagram and it is most likely December, but it could also be November. CHECK FOR UNDERSTANDING #2 Pisces Aquarius Capricorn Sagittarius Scorpio Libra Virgo Leo Cancer Gemini Taurus Aries

33. RESOURCE PAGE