The gravitational force between planets works the same way gravity works everywhere else in the universe: it gets stronger with increasing mass and weaker with increasing distance.
Here's a breakdown:
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Newton's Law of Universal Gravitation: This law fundamentally explains gravity between any two objects with mass, including planets. The equation is:
- F = G * (m1 * m2) / r^2
- Where:
- F is the gravitational force
- G is the gravitational constant (a universal number)
- m1 and m2 are the masses of the two objects (planets in this case)
- r is the distance between the centers of the two objects
- Where:
- F = G * (m1 * m2) / r^2
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Mass Matters: The more massive a planet is, the stronger its gravitational pull. A larger mass directly translates to a stronger gravitational force. For example, Jupiter, being the most massive planet in our solar system, has a significantly stronger gravitational pull than Earth.
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Distance Diminishes: The farther apart two planets are, the weaker the gravitational force between them. The force decreases with the square of the distance. This means if you double the distance, the gravitational force becomes four times weaker (1/2^2 = 1/4).
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Planetary Orbits: The Sun's immense mass dominates the gravity within our solar system. It's this gravitational dominance that keeps all the planets in orbit around it. The planets also exert gravitational forces on each other, causing slight perturbations (deviations) in their orbits.
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Example: Consider Earth and Mars. Earth is more massive than Mars. Therefore, Earth exerts a stronger gravitational force on Mars than Mars exerts on Earth. Additionally, as Mars' orbit takes it further from Earth, the gravitational force between the two planets weakens.
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In summary: Gravity between planets (and all objects with mass) is a fundamental force that depends on the mass of the objects and the distance separating them. More mass means stronger gravity; greater distance means weaker gravity.
