NCERT Solutions Class 7 Science Chapter 12 Earth, Moon and, the Sun
Earth, Moon and Sun is the 12th Chapter of Class 7 Science and its focus is to explores the Earth, Moon, and Sun in detail, explaining their movements and interrelationships. It covers the concept of rotation and revolution, phases of the Moon, eclipses, and how these phenomena influence day, night, tides, and seasons.
The NCERT Solutions Class 7 Science Chapter 12 provide detailed, step-by-step explanations to simplify complex astronomical concepts covered in the questions at the end of the chapter. These solutions enhance conceptual clarity, improve answer-writing accuracy, and help students prepare effectively for exams with confidence.
1.0NCERT Solutions Class 7 Science Chapter 12 Earth, Moon and the Sun – Download PDF
Learn how the Earth, Moon, and Sun interact through rotation, revolution, phases, and eclipses. Download NCERT Solutions Class 7 Science Chapter 12 PDF to gain clear explanations, improve understanding, and excel in exams.
2.0Earth, Moon and the Sun Class 7 Science Chapter 12 – Revision Notes
The Earth's rotation causes day and night. Its tilted axis and revolution cause seasons, and the Sun, Earth and Moon lining up causes eclipses.
Key Concepts:
- Rotation: The Earth spins on its axis from west to east in about 24 hours. This causes day and night.
- Apparent Motion: The Sun, Moon and stars seem to rise in the east and set in the west because the Earth rotates.
- Revolution: The Earth moves around the Sun in a fixed path called its orbit. It takes about 365 days and 6 hours.
- Tilted Axis: The Earth's axis is tilted by about 23.5°. With revolution, this causes seasons.
- Solar Eclipse: The Moon comes between the Sun and the Earth.
- Lunar Eclipse: The Earth comes between the Sun and the Moon.
Rotation of the Earth:
- The Earth spins on an imaginary axis through the North and South Poles.
- Seen from above the North Pole, it turns anti-clockwise, from west to east.
- The Sun does not really move. Its motion is only apparent, like trees seeming to move when you spin on a merry-go-round.
- The side facing the Sun has day. The other side has night.
- Eastern India sees sunrise first because the Earth turns from west to east.
At the Equator, the Sun is in the east in the morning, overhead at noon and in the west in the evening.
- Foucault used a long pendulum to give the first simple proof that the Earth rotates.
Stars in the Night Sky:
- Stars seem to rise in the east and set in the west because of the Earth's rotation.
- The Pole Star (Dhruva Tara) seems fixed because the Earth's axis points almost at it. Other stars seem to circle around it.
- Long exposure photographs show this motion as star trails.
- Aryabhata explained star motion with trees seen from a moving boat. He gave the rotation time as 23 hours, 56 minutes and 4.1 seconds.
Revolution and Orbit:
- Orbit is the path of an object revolving around another object.
- The extra 6 hours each year add up to one day in four years. This day is added as 29 February in a leap year of 366 days.
- As the Earth orbits the Sun, the night sky after sunset changes slowly through the year.
Seasons:
- Seasons are caused by the axis tilt and the Earth's revolution.
- In June the Northern Hemisphere tilts towards the Sun. It gets more direct sunlight and longer days, so it has summer.
- In December it tilts away. It gets less direct sunlight and shorter days, so it has winter.
- The Southern Hemisphere has opposite seasons.
- Places near the Equator, like southern India, have 12 hours of day and night all year, so seasons are not clear.
- Seasons are not caused by distance from the Sun. The Earth is closest to the Sun in January.
- Summer solstice: About 21 June, longest day in the Northern Hemisphere.
- Winter solstice: About 22 December, shortest day.
- Equinoxes: About 21 March and 23 September, day and night nearly equal.
- Near the poles, six months of daylight are followed by six months of darkness.
- A greater tilt would make seasons more extreme. Uranus is tilted about 98°, so its poles get about 42 years of sunlight, then 42 years of darkness.
Solar Eclipse:
- It happens at new moon, when the Moon passes between the Sun and the Earth.
- The Moon is much smaller than the Sun but much closer, so both look nearly the same size.
- Total: The Moon fully covers the Sun. It is seen from the umbra, a small region, and only for a few minutes.
- Partial: The Moon covers part of the Sun. It is seen from the penumbra, a much larger area.
- Annular: The Moon cannot cover the Sun fully, so a bright ring remains.
- Mercury and Venus are too far away to block the Sun.
Lunar Eclipse:
- It happens at full moon, when the Earth comes between the Sun and the Moon.
- It can be seen from everywhere the Moon is above the horizon.
- Total: The whole Moon is in the umbra and looks dark red.
- Partial: Only part of the Moon is in the umbra.
- Penumbral: The Moon is only in the penumbra and dims slightly.
- It is safe to see with the naked eye.
Umbra and Penumbra:
- Umbra: The darkest part of a shadow, where no light reaches.
- Penumbra: The lighter part around the umbra, where only some light is blocked.
3.0Chapter 12 Terminologies to Know – Earth, Moon and the Sun:
- Rotation: Spinning of an object around its axis.
- Axis: The imaginary line about which an object spins.
- Revolution: Movement of the Earth around the Sun.
- Orbit: Path of an object around another object.
- Apparent motion: Motion that seems to happen because of the viewer's own movement.
- Pole Star: A star that seems fixed because it lies near the Earth's axis.
- Constellation: A group of stars forming a pattern.
- Celestial objects: Stars, planets, the Moon and other objects in the sky.
- Leap year: A year of 366 days.
- Solstice: The longest or shortest day of the year.
- Equinox: A day when day and night are nearly equal.
- Eclipse: Hiding of one celestial object by another.
- Umbra: Darkest part of a shadow.
- Penumbra: Lighter part of a shadow.
- Annular eclipse: A solar eclipse with a ring of the Sun visible.
4.0Learning Guide for Class 7 Science – Earth, Moon and the Sun:
- Merry-go-round Activity: Sit facing outward as it turns anti-clockwise. Observation: Objects around seem to move clockwise, like the Sun's apparent motion.
- Globe Rotation Activity: Mark your place on a globe and turn it anti-clockwise as seen from above the North Pole. Observation: Your place returns to its start after one rotation.
- Globe and Torch Activity: Shine a torch on a globe in a dark room and turn it west to east. Observation: One half is lit (day) and the other is dark (night). Eastern India is lit first.
- Big Dipper Activity: Sketch the Big Dipper against the Pole Star every two hours on the same night. Observation: It seems to circle the Pole Star.
- Coin and Clock Activity: Cover a wall clock with a coin held at arm's length. Observation: A small near object can hide a large far one, like the Moon and the Sun.
- Mirror Projection Activity: Fix a small mirror on a ball half-filled with sand and project the Sun's image on a wall. Observation: The Sun can be seen safely without looking at it.
Everyday Examples:
- Long shadows in the evening and short shadows at noon.
- Sunrise, sunset and stars appearing after dark.
- Sweaters in winter and light clothes in summer.
Revision Tips:
- Rotation gives day and night. Revolution with tilt gives seasons.
- Solar eclipse: new moon, Moon between Sun and Earth. Lunar eclipse: full moon, Earth between Sun and Moon.
- Solstices: 21 June and 22 December. Equinoxes: 21 March and 23 September.
Safety Rules:
- Never look directly at the Sun during an eclipse, even through sunglasses, binoculars or telescopes. It can cause permanent blindness.
- Do the mirror projection activity only with a teacher. Never point the reflected beam at anyone's eyes.
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8.0Key Features and Benefits of NCERT Solutions Class 7 Science Chapter 12
- Accurate & Aligned: Solutions strictly follow NCERT content, ensuring clarity and compliance with the latest 2025–26 syllabus.
- Concise Answers: Includes Very‑Short, Short, and Long Answer formats with relevant diagrams (e.g. Earth’s tilt, eclipse geometry).
- Educational Activities: Solutions enhance classroom experiments like globe‑torch demonstrations and star observations.
- Diagram Practice: Supports drawing of phases, orbits, and alignment during eclipses to help visual learning.
- Conceptual Clarity: Explains terms like rotation, revolution, orbit, tilt, solstice, equinox, lunar phase, eclipse, etc.
- Quick Revision Points: Summaries and “Points to Remember” lists enhance last‑minute revision efficiency.