These DAV Class 5 Science Notes and DAV Class 5 Science Chapter 12 Notes – Observing The Sky act as excellent revision resources, particularly in preparation for board exams.
Observing The Sky Class 5 DAV Notes
→ Day Time Sky: The sun dominates the day time sky. We can also see the moon sometimes during day. Mercury and Venus also appear sometimes during early morning or early evening. Hence, these are often called the ‘morning and evening stars’. Since the earth rotates from west to east, the apparent path of the sun in the sky is from east to west.
→ Night Time Sky: The stars dominate the night time sky. We can also see the planets and the moon in night sky. Some planets can be seen by naked eye, e.g. Venus, Mars, Tupiter and Saturn.
→ Pole Star: Pole Star is known as Dhruvtara in Hindi. This is a unique star because its position in the night sky never changes. This happens because the Pole Star is in line with the axis of the earth. All other stars appear to rotate around the Pole Star. Pole Star has been used by travellers to find direction; since ages.
→ Identifying the Planets in the Sky
→ Planets appear as tiny discs while a star appears like point because planets are closer to us than stars.
→ Stars appear to twinkle, while planets do not twinkle.
→ Stars do not appear to change their relative positions. They appear almost stationary. But the planets appear to change their relative positions. In fact, the term ‘planet’ means ‘wandering star’.
→ Changing Night Sky: The apparent position of stars also appears to change from east to west; the way it happens with the sun and the moon.
→ Constellation: A group of stars which resembles recognizable shape.
→ Star: Huge celestial bodies which emit their own light.
→ Pole Star: The star which never changes its position in the night sky.