Earth Moon and the Sun Class 7 Notes

Earth Moon and the Sun Class 7 Notes

Earth Moon and the Sun Class 7 Notes

1. Rotation: The spinning motion of the Earth around its own axis, which takes approximately 24 hours to complete one full turn. This motion causes day and night.
2. Revolution: The movement of the Earth around the Sun in an elliptical orbit, taking about 365.25 days to complete one full cycle. This motion is responsible for the changing seasons.
3. Equator: An imaginary line that divides the Earth into the Northern and Southern Hemispheres, located equidistant from the poles. It is the reference point for latitude at 0 degrees.
4. Celestial Objects: Natural objects in space, such as stars, planets, moons, and asteroids. These objects can be observed from Earth and exhibit apparent motion due to the Earth's rotation and revolution.
5. Foucault Pendulum: A device that demonstrates the rotation of the Earth. It consists of a long string with a heavy bob that swings freely, showing the rotation of the Earth beneath it.
6. Aryabhata: An ancient Indian mathematician and astronomer who made significant contributions to astronomy, including observations about the apparent motion of celestial objects.
7. Apparent Motion: The perceived movement of celestial objects across the sky as observed from Earth, which is caused by the rotation of the Earth on its axis.
8. Sunlight Intensity: The strength or brightness of sunlight that reaches the Earth's surface, which varies based on the angle of sunlight and the Earth's tilt. This affects climate and seasons.
9. Northern Hemisphere: The half of the Earth that is north of the Equator, experiencing different seasons and daylight hours compared to the Southern Hemisphere.
10. Southern Hemisphere: The half of the Earth that is south of the Equator, experiencing seasons and daylight hours that are opposite to those in the Northern Hemisphere.
11. Seasons: The four divisions of the year (spring, summer, autumn, winter) that result from the tilt of the Earth's axis and its revolution around the Sun.
12. Cosmos: The universe seen as a whole.
13. Orientation: Position; direction; or location.
14. Astrophotographer: A person who takes photographs of celestial objects, phenomena, and events, such as stars, planets, and eclipses.
15. Astronomer: A scientist who studies the objects in the sky, including planets, galaxies, black holes, and stars.
16. Indigenous: Occurring naturally in a particular place; native.
17. Autumn equinox: Marks the end of summer and the beginning of autumn.
18. Summer solstice: Marks the official start of astronomical summer and the longest day of the year.
19. Winter solstice: The day with the shortest period of daylight and longest night of the year.
20. Transit: Passage from one place to another.

1. Earth's Rotation:

Observation: The Sun appears to rise in the East and set in the West due to this rotation.

2. Day and Night Cycle:

Description: The cycle created by Earth's rotation, leading to day time when a location is facing the Sun and night time when it is turned away.

3. Sun's Position:

Morning: The Sun rises in the East.

Noon: The Sun is at its highest point in the sky.

Evening: The Sun sets in the West.

4. Shadows:

Observation: Shadows change in length and direction throughout the day due to the Sun's apparent movement across the sky.

5. Lunar Eclipse:

Types:

1. Total Lunar Eclipse: The Moon is completely in the Earth's shadow, appearing red.
2. Partial Lunar Eclipse: Only part of the Moon is in the Earth's shadow.

6. Solar Eclipse:

Observation: The Moon can appear to cover the Sun, despite being smaller, due to its position.

Scientific Understanding: Modern science explains the mechanics behind eclipses, allowing for safe observation.

7. Foucault Pendulum:

Purpose: Demonstrates Earth's rotation through the changing direction of the pendulum's swing.

8. Astronomical Observatories:

Example: Kodaikanal Solar Observatory, which has contributed to solar studies for over a century.

9. Stellarium App:

Function: A tool for predicting and observing solar and lunar eclipses.