🌟 Class
7 Science Curiosity – Chapter 12 Notes
🌍 Earth,
Moon, and the Sun | Amresh Academy
📘 1.
Introduction
👉 We
observe that shadows change length during the day 🌴
🧠
Reason:
- Not
Sun moving ❌
- Earth
rotates on its axis ✔️
🌍 2.
Rotation of the Earth
🔄
Definition:
👉
Rotation = spinning of Earth on its axis
📌 Key
Points:
- Axis
passes through:
- North
Pole ❄️
- South
Pole ❄️
- Direction:👉 West → East (anticlockwise)
- Time:👉 1 rotation = 24 hours ⏳
🎡 3.
Understanding Rotation (Activity)
👉
Merry-go-round example:
- When
you rotate → objects seem to move
opposite 🔄
- Same
happens with Earth
🌞🌙 4. Day
and Night
📌 Cause:
👉
Earth’s rotation
🌍
Explanation:
- Half
Earth → Day ☀️
- Other
half → Night 🌙
🌅
Sunrise & Sunset:
- Sun
rises in East 🌅
- Sets
in West 🌇
🌎 5.
Globe Activity
👉 Use
globe + torch 🔦
Observation:
- Light
side → Day
- Dark
side → Night
🇮🇳 6.
Sunrise in India
👉
Sunrise happens first in eastern India
☀️ 7.
Apparent Motion of Sun
👉 Sun
appears to:
- Rise
in East
- Move
across sky
- Set
in West
🧭 8.
Demonstration of Earth’s Rotation
🔄
Foucault Pendulum
👉
Demonstrates Earth’s rotation
👨🔬
Scientist: Leon Foucault
📍
Example: Installed in New Parliament, Delhi
⭐ 9.
Apparent Motion of Stars
👉 Stars
appear to move 🌌
Example:
- Big
Dipper (Saptarishi)
- Pole
Star (Dhruva Tara)
⭐ Pole
Star:
👉
Appears fixed
🌙 Moon:
👉 Also
appears to rise East & set West
🌠 10.
Star Trails
📷
Long-exposure photos show:
👉 Stars
as circular arcs
📌
Called: Star Trails
🇮🇳 11.
Ancient Indian Astronomy
👨🔬
Aryabhata
- Explained
star movement
- Said
Earth rotates
☀️ 12.
Revolution of the Earth
🔄
Definition:
👉
Movement around Sun
📌 Key
Points:
- Path
= Orbit 🌀
- Shape
= Nearly circular
⏳ Time:
👉 365
days + 6 hours = 1 year
🌌 13.
Changing Night Sky
👉 Stars
change over months
📌 Used
by tribes (Bhil, Pawara) to predict monsoon 🌧️
🌦️ 14–15.
Seasons on Earth
📌
Causes:
- Tilt
of Earth’s axis
- Shape
of Earth
🌞 16–17.
Summer (Northern Hemisphere)
👉 Around
June
- Tilted
toward Sun
- More
heat 🔥
- Longer
days
❄️ 18.
Winter (Northern Hemisphere)
👉 Around
December
- Tilted
away from Sun
- Less
heat
- Shorter
days
🌍 19.
Southern Hemisphere
👉
Opposite seasons:
- June
→
Winter
- December
→
Summer
🌞 20.
Solstices
- 🌞
Summer Solstice → 21 June (longest day)
- ❄️ Winter Solstice →
22 Dec (shortest day)
⚖️ 21.
Equinox
👉 Day =
Night (12 hours)
- 🌸
Spring → 21 March
- 🍂
Autumn → 23 September
🧊 22.
Poles Situation
- Sun
visible for 6 months ☀️
- Darkness
for 6 months 🌙
🌍 23.
Equator
👉 Day
& night almost equal
👉 No
extreme seasons
🌘 24–25.
Eclipses
🌑 Solar
Eclipse
👉 Sun → Moon → Earth
- Moon
blocks sunlight
Types:
- Total
eclipse
- Partial
eclipse
💍 26.
Diamond Ring Effect
👉 Bright
ring seen during eclipse 💎
⚠️ 27.
Safety
👉 Never
look directly at Sun
✔️ Use:
- Special
glasses
- Projection
method
🧠 28.
Superstitions
🌕 29.
Lunar Eclipse
👉 Sun → Earth → Moon
Types:
- Total
(red moon) 🔴
- Partial
👉 Safe
to watch ✔️
🔭 30.
Astronomy in India
📍
Kodaikanal Solar Observatory (Tamil Nadu)
👉
Studies Sun
👨🔬 31.
Indian Scientist
🌟 M. K.
Vainu Bappu
- Father
of Modern Indian Astronomy
- Built
observatories in India
📌 32.
Final Summary
✨ Perfect
for revision + exams + teaching 🚀
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