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REET Level 1 · EVS

The Solar System — REET EVS Notes

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This page covers the structure of the solar system — the Sun, the order of the eight planets, their relative sizes, and other bodies (moons, satellites, asteroids). In REET EVS, this topic is tested through direct questions on the order of planets, size comparisons, and basic astronomical facts.

  • 1 question in REET 2024
  • Class 1–5 level
  • 6 min read
Verified 17 September 2026 · Source: NCERT Curiosity — Class 6 Science, Chapter 12: Beyond Earth

How this topic is asked in REET

REET 2024 asked which is the largest planet in our solar system — the correct answer was Jupiter. This shows that REET asks direct factual questions on planet size, order, and basic characteristics (biggest/smallest/closest to the Sun) from this topic, all pitched at a level appropriate for Class 1-5.

The Eight Planets of the Solar System, in Order from the Sun

OrderPlanetDistinguishing feature
1MercuryClosest to the Sun, the smallest planet
2VenusThe hottest planet; the brightest object in the direction of sunrise (the 'evening/morning star')
3EarthThe only planet known to support life; has one natural satellite (the Moon)
4MarsThe 'Red Planet'; has two moons (Phobos and Deimos)
5JupiterThe largest planet in the solar system
6SaturnFamous for its beautiful rings; the second-largest planet
7UranusRotates almost lying on its side
8NeptuneThe planet farthest from the Sun

A simple way to remember the order: 'My Very Educated Mother Just Served Us Nachos' (Mercury-Venus-Earth-Mars-Jupiter-Saturn-Uranus-Neptune) — this order follows distance from the Sun.[Source 1]

The Structure of the Solar System

The Sun sits at the centre of the solar system, and the eight planets revolve around it in their own fixed paths (orbits). The Sun is a star that generates its own light and heat, while planets reflect the Sun's light and don't produce any light of their own.

Besides the planets, the solar system also includes satellites (moons that orbit planets — such as Earth's Moon), asteroids (found mainly in the belt between Mars and Jupiter), and comets (bodies of ice and dust that orbit the Sun in long, elongated paths).

The solar system's eight planets are grouped into two types based on their composition — the inner rocky planets (Terrestrial Planets: Mercury, Venus, Earth, Mars), which are smaller but denser, and the outer gas giants (Gas Giant Planets: Jupiter, Saturn, Uranus, Neptune), which are larger but made mostly of gas. Between these two groups lies the Asteroid Belt, stretching between the orbits of Mars and Jupiter. The solar system itself is only a tiny part of a vast collection of stars called the Milky Way Galaxy, which contains billions of stars.

Earth's Motion — Rotation and Revolution

Earth spins on its own axis, which is called rotation — this takes about 24 hours to complete and is what causes day and night. At the same time, Earth also revolves around the Sun along a fixed path, which is called revolution and takes about 365¼ days — it's this revolution combined with the 23.5° tilt of Earth's axis that causes the seasons to change.

Once every four years, an extra day (29 February) is added to the month of February, which is called a leap year — this makes up for the roughly extra 6 hours that build up each year beyond the 365 days of revolution. In EVS this concept also connects to topics like 'our surroundings and the calendar', so it's worth understanding clearly why day-night and the seasons change.

Pluto and Dwarf Planets

Pluto used to be considered the ninth planet of the solar system, but the International Astronomical Union (IAU) set a new definition of 'planet' in 2006, which reclassified Pluto as a 'dwarf planet'. This is why the solar system currently has 8 recognised planets, not 9 — keep this updated fact in mind for exams like REET. Besides Pluto, Ceres, Eris, Haumea and Makemake are also currently classified as 'dwarf planets'.

Interesting Solar System Facts

Largest planet
Jupiter
Smallest planet
Mercury
Hottest planet
Venus — due to its high temperature from a dense atmosphere
Planet closest to the Sun
Mercury
Planet farthest from the Sun
Neptune
Known as the 'Red Planet'
Mars
Fastest-orbiting planet
Mercury — completes one orbit of the Sun in only about 88 days
Planet with the most moons
Saturn has the highest number of confirmed natural satellites (over 140), more than even Jupiter
The Sun
The centre of the solar system and its only star; its diameter is roughly 109 times that of Earth

How to Teach This to Children

Classroom activity

Build a model of the solar system using balls of different sizes, and have children arrange the planets in order by distance and size from the Sun — this activity reinforces both order and relative size.

Teaching aids

Show stars and the moon in the night sky as real observation (where possible), or use pictures/videos to show the solar system — visual experience sparks deep interest in Class 3-5 children.

Common misconception

Children often think stars and planets are the same thing, or still consider Pluto a planet because older textbooks say so. Teachers should clear up both misconceptions with clear examples and updated information.

Assessment idea

Ask children to arrange the planets in the correct order of distance from the Sun (by cutting out pictures or writing names) — a simple, order-based assessment activity.

Hands-on experiment

Demonstrate day and night with a simple experiment using a torch (the Sun) and a ball (Earth) — rotate the ball to show children that the side facing the torch is 'day' and the side facing away is 'night'.

Memory trick

Remember the order of planets with this line: 'Mercury Venus Earth Mars, Jupiter Saturn Uranus Neptune'. Jupiter is the biggest and Mercury is the smallest — lock in these two 'ends' firmly, since REET asks exactly these two facts the most.

REET 2024 Questions (Solved)

Question 131

Which is the largest planet of our solar system ?

  1. Aअरुण
  2. Bवरुण
  3. Cबृहस्पति
  4. Dशनि

Explanation

बृहस्पति (Jupiter) हमारे सौर मण्डल का सबसे बड़ा ग्रह है; इसका आकार अन्य सभी ग्रहों से बड़ा है। शनि दूसरा सबसे बड़ा ग्रह है, जबकि अरुण (Uranus) और वरुण (Neptune) इनसे छोटे हैं।

Practice Questions

Question 1

Which is the smallest planet in the solar system?

  1. Aबुध
  2. Bशुक्र
  3. Cमंगल
  4. Dवरुण

Explanation

Mercury is the smallest planet in the solar system, and it's also the planet closest to the Sun.

Question 2

In order of distance from the Sun, at which position is Earth?

  1. Aदूसरे
  2. Bतीसरे
  3. Cचौथे
  4. Dपाँचवें

Explanation

Earth is third in order of distance from the Sun (Mercury, Venus, Earth).

Question 3

Which planet is located farthest from the Sun in the solar system?

  1. Aशनि
  2. Bअरुण
  3. Cवरुण
  4. Dबृहस्पति

Explanation

Neptune is the planet farthest from the Sun in the solar system.

Question 4

Which planet is most famous for its beautiful rings?

  1. Aबृहस्पति
  2. Bशनि
  3. Cमंगल
  4. Dशुक्र

Explanation

Saturn is the most famous of all for its beautiful rings.

Question 5

Which is the hottest planet in the solar system?

  1. Aबुध
  2. Bशुक्र
  3. Cमंगल
  4. Dबृहस्पति

Explanation

Venus is the hottest planet in the solar system because of its dense atmosphere, even though Mercury is closest to the Sun.

Question 6

What is Earth's only natural satellite?

  1. Aसूर्य
  2. Bचंद्रमा
  3. Cमंगल
  4. Dशुक्र

Explanation

The Moon is Earth's only natural satellite, orbiting the Earth.

Question 7

What is the main difference between a star and a planet?

  1. Aतारे स्वयं प्रकाश उत्पन्न करते हैं, ग्रह सूर्य के प्रकाश को परावर्तित करते हैं
  2. Bदोनों बिल्कुल समान हैं
  3. Cग्रह स्वयं प्रकाश उत्पन्न करते हैं
  4. Dतारे कभी नहीं चमकते

Explanation

Stars (like the Sun) generate their own light and heat through internal nuclear processes, while planets reflect the Sun's light.

Question 8

Which is the most effective activity for teaching Class 4-5 children the order of the planets in the solar system?

  1. Aकेवल नाम याद करवाना
  2. Bअलग-अलग आकार की गेंदों से मॉडल बनवाकर क्रम में सजवाना
  3. Cजटिल खगोलीय गणना करवाना
  4. Dटॉपिक को छोड़ देना

Explanation

A concrete, hands-on model-building activity helps children remember both the order and the relative sizes of the planets better.

Question 9

Why is Mars called the 'Red Planet'?

  1. Aउस पर हमेशा लाल बादल छाए रहते हैं
  2. Bउसकी सतह पर आयरन ऑक्साइड (जंग) की अधिकता के कारण
  3. Cवह सूर्य के सबसे निकट है
  4. Dउस पर पानी बहुत अधिक है

Explanation

Mars appears red because of the abundance of iron oxide (a rust-like compound) on its surface.

Question 10

Between Jupiter and Saturn, which is the second-largest planet in the solar system?

  1. Aबृहस्पति
  2. Bशनि
  3. Cदोनों बराबर हैं
  4. Dअरुण

Explanation

Jupiter is the largest planet, and Saturn is the second-largest, while Uranus and Neptune are considerably smaller than both.

Frequently Asked Questions

Which is the largest planet in the solar system?+

Jupiter is the largest planet in the solar system.

Which is the smallest planet in the solar system?+

Mercury is the smallest planet in the solar system, and it's also the planet closest to the Sun.

What is the correct order of planets by distance from the Sun?+

In order of distance from the Sun, the planets are — Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune.

Why is Mars called the 'Red Planet'?+

Mars appears red because of an abundance of iron oxide (rust) on its surface, which is why it's called the 'Red Planet'.

Is Pluto still considered the ninth planet of the solar system?+

No. In 2006 the International Astronomical Union (IAU) reclassified Pluto as a 'dwarf planet', so the number of recognised planets in the solar system is now 8.

Why do we have day-night and seasons?+

Earth's rotation on its own axis causes day and night, and the tilt of Earth's axis combined with its revolution around the Sun causes the seasons to change.

How many groups are the solar system's planets divided into?+

The solar system's eight planets are divided into two groups — the inner rocky planets (Mercury, Venus, Earth, Mars) and the outer gas giants (Jupiter, Saturn, Uranus, Neptune), with the asteroid belt located between them.

Read Next

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Previous EVS topic — means of transport and communication.

Indian Astronauts and ISRO

Next EVS topic — India's space programme and astronauts.

REET Syllabus

The complete REET Level 1 and Level 2 syllabus in one place.

REET 2024 Solved Paper

All REET 2024 questions with explanations.

Official Sources

  1. NCERT Curiosity — Class 6 Science, Chapter 12: Beyond Earth

Change Log

  • 17 September 2026 — English page published — mirrors the fact-checked Hindi page, independently bilingual-accuracy checked