Grade 5 Science Worksheet: Earth and Space - The Solar System

Problem: Solving the Science Worksheet on the Solar System

The worksheet asks for definitions and facts about the solar system. Below is a detailed explanation and solution for each question.

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#### 1. Define the term "solar system"
- Answer: The solar system is a group of celestial bodies, including planets, moons, asteroids, comets, and other objects, that orbit around a central star called the Sun due to its gravitational pull.

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#### 2. There are _______ planets in the solar system.
- Answer: 8
- Explanation: The solar system has eight recognized planets: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune. Pluto was reclassified as a "dwarf planet" in 2006.

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#### 3. The hottest planet in the solar system is _______ while the coldest planet in the solar system is _______.
- Answer:
- Hottest planet: Mercury
- Coldest planet: Neptune
- Explanation:
- Mercury: It is the closest planet to the Sun, so it experiences extremely high surface temperatures (up to 430°C during the day).
- Neptune: It is the farthest planet from the Sun, so it is very cold with average temperatures around -214°C.

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#### 4. The fourth planet away from the sun is _______ and it is often referred to as the _______.
- Answer:
- Fourth planet: Mars
- Nickname: Red Planet
- Explanation:
- Mars is the fourth planet from the Sun.
- It is called the "Red Planet" because its surface appears reddish due to iron oxide (rust) in its soil.

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#### 5. The _______ is in the centre of the solar system.
- Answer: Sun
- Explanation: The Sun is the central star of the solar system and provides the gravitational force that keeps all the planets, moons, and other objects in orbit.

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#### 6. Scientists decide to visit a planet that has life on it. Which planet are they more likely to visit?
- Answer: Earth
- Explanation: Earth is the only known planet in the solar system that supports life. All other planets lack the necessary conditions (e.g., atmosphere, liquid water, suitable temperature range) for life as we know it.

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#### 7. Identify the planet which has rings around it.
- Answer: Saturn
- Explanation: Saturn is famous for its prominent ring system, which is made up of countless small ice particles and rocks held together by gravity. Other planets like Jupiter, Uranus, and Neptune also have rings, but Saturn's are the most visible and well-known.

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#### 8. _______ is known as the King of Moons.
- Answer: Jupiter
- Explanation: Jupiter has the largest number of moons in the solar system (over 90 confirmed moons). Its largest moon, Ganymede, is even bigger than the planet Mercury.

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#### 9. _______ is the most distant planet in the solar system.
- Answer: Neptune
- Explanation: Neptune is the eighth and farthest planet from the Sun. It orbits at an average distance of about 4.5 billion kilometers from the Sun.

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#### 10. _______ is the smallest planet in the solar system and the _______ planet to the Sun.
- Answer:
- Smallest planet: Mercury
- Position: closest
- Explanation:
- Mercury is the smallest planet in terms of size.
- It is also the closest planet to the Sun.

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#### 11. Uranus has _______ moons.
- Answer: 27
- Explanation: Uranus has 27 known moons. Some of the larger ones include Miranda, Ariel, Umbriel, Titania, and Oberon.

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#### 12. The tilted planet is _______.
- Answer: Uranus
- Explanation: Uranus is unique because it rotates on its side, with its axis tilted almost perpendicular to its orbital plane. This tilt causes extreme seasonal changes, with each pole experiencing 42 years of continuous daylight followed by 42 years of darkness.

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Final Answers:

1. The solar system is a group of celestial bodies orbiting a central star, the Sun.
2. 8
3. Mercury; Neptune
4. Mars; Red Planet
5. Sun
6. Earth
7. Saturn
8. Jupiter
9. Neptune
10. Mercury; closest
11. 27
12. Uranus

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Final Answer Box:
\boxed{
\begin{array}{l}
1. \text{The solar system is a group of celestial bodies orbiting a central star, the Sun.} \\
2. 8 \\
3. \text{Mercury; Neptune} \\
4. \text{Mars; Red Planet} \\
5. \text{Sun} \\
6. \text{Earth} \\
7. \text{Saturn} \\
8. \text{Jupiter} \\
9. \text{Neptune} \\
10. \text{Mercury; closest} \\
11. 27 \\
12. \text{Uranus} \\
\end{array}
}