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CIE iGCSE Co-ordinated Sciences-P6.1 The Solar System- Study Notes- New Syllabus

CIE iGCSE Co-ordinated Sciences-P6.1 The Solar System – Study Notes

CIE iGCSE Co-ordinated Sciences-P6.1 The Solar System – Study Notes -CIE iGCSE Co-ordinated Sciences – per latest Syllabus.

Key Concepts:

CIE iGCSE Co-Ordinated Sciences-Concise Summary Notes- All Topics

The Solar System

(a) The Sun:

    • The Solar System contains one star – the Sun.
    • The Sun is a medium-sized yellow star (G-type main-sequence).
    • Contains about 99.9% of the total mass of the Solar System.
    • Source of light and heat for all planets.
    • Provides the gravitational force that keeps planets and other bodies in orbit.
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(b) The Eight Planets (in order from the Sun):

  • Mercury – smallest planet, closest to the Sun, no atmosphere.
  • Venus – thick carbon dioxide atmosphere, hottest planet.
  • Earth – only known planet with life, water in all three states.
  • Mars – the “Red Planet”, thin atmosphere, polar ice caps.
  • Jupiter – largest planet, gas giant, Great Red Spot storm.
  • Saturn – gas giant, famous for its ring system.
  • Uranus – ice giant, tilted axis (rotates on its side).
  • Neptune – farthest planet, strong winds, ice giant.

Mnemonic:My Very Educated Mother Just Served Us Noodles

(c) Minor Planets and Other Bodies:

    • Dwarf Planets: e.g., Pluto, Eris, Ceres – smaller bodies orbiting the Sun.
    • Asteroids: Rocky objects, mostly found in the asteroid belt between Mars and Jupiter.
    • Comets: Made of ice and rock; develop tails when near the Sun due to sublimation of ice.
    • Meteoroids: Small rocky fragments that can enter Earth’s atmosphere as meteors.

(d) Moons (Natural Satellites):

    • Moons orbit planets due to gravity.
    • Earth’s Moon stabilises Earth’s tilt and causes tides.
    • Jupiter has at least 79 moons (largest: Ganymede, Io, Europa, Callisto).
    • Saturn has over 80 moons (including Titan, larger than Mercury).
    • Moons vary in size from tiny asteroid-like rocks to planet-sized bodies.

Example

Which planet is the farthest from the Sun, and what are two of its key features?

▶️Answer/Explanation

Step (1): The farthest planet from the Sun is Neptune.

Step (2): Key features include:

  • It is an ice giant with a thick atmosphere of hydrogen, helium, and methane.
  • It has the strongest winds in the Solar System (up to 2000 km/h).

Final Answer: Neptune – farthest planet, ice giant with extreme winds.

Example 

Write down the eight planets of the Solar System in order, starting from the Sun.

▶️Answer/Explanation

Step (1): Recall the order using the mnemonic “My Very Educated Mother Just Served Us Noodles.”

Step (2): Planets in order:

Final Answer: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune.

Example 

Pluto is no longer classified as a major planet. State its current classification and one reason for this change.

▶️Answer/Explanation

Step (1): Pluto was reclassified in 2006 by the International Astronomical Union (IAU).

Step (2): Its current classification is a dwarf planet.

Step (3): Reason: Pluto does not clear its orbit of other debris, one of the conditions required to be called a planet.

Final Answer: Pluto is a dwarf planet because it shares its orbit with other objects in the Kuiper Belt.

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