Theories related to the origin of the moon
1. The Giant Impact Hypothesis (Also known as the Big Whack or the Theia Impact)
– This is the most widely accepted theory for the Moon’s formation.
– It suggests that around 4.5 billion years ago, a Mars-sized object called Theia collided with the early Earth.
– The immense impact blasted out a massive amount of debris from the Earth’s mantle and crust.
– This debris went into orbit around the Earth and eventually coalesced to form the Moon.
– This explains the Moon’s smaller size, its relatively thin crust, and the similarities in composition between the Moon’s rocks and Earth’s mantle.
2. The Fission Hypothesis
– This older theory proposes that the Moon split away from the Earth when the Earth was still a rapidly rotating, partially molten mass.
– The centrifugal force caused a chunk of the Earth to break off and form the Moon.
– However, this theory fails to explain the Moon’s relatively small iron core and the angular momentum of the Earth-Moon system.
3. The Capture Theory
– This theory suggests that the Moon formed elsewhere in the solar system and was later captured by the Earth’s gravitational pull.
– However, the chances of such a capture are extremely low, and it cannot explain the similarities between the Earth and Moon’s composition.
4. The Co-Formation Theory
– This theory proposes that the Earth and Moon formed together from the same spinning cloud of gas and dust, rather than the Moon forming from the Earth’s debris.
– However, it cannot fully explain the differences in composition between the two bodies.
5. The Accretion Hypothesis
– This theory suggests that the Moon and Earth accumulated from the same material in the early solar system, with the Moon forming closer to the Earth than other planets.
– However, it does not account for the angular momentum of the Earth-Moon system or the Moon’s lack of iron core.
Formation of Star, Planet and Solar System Class 11 Notes
The Universe is a vast expanse filled with celestial bodies, each with its unique formation process and characteristics. From stars that illuminate the cosmos to planets that orbit around them, understanding their origins and evolution is a captivating field of study. This text delves into the intricate processes that give rise to these celestial wonders, shedding light on the theories and mechanisms that shape our cosmic neighborhood.
Let us learn in detail about the formation of stars, planets, and solar system!
Formation of Star, Planet and Solar System Class 11 Notes