1. What is Surface Gravity?

Surface gravity (g) is the gravitational acceleration experienced at the surface of a celestial body. It determines the weight of objects and influences atmospheric retention and geological processes on planets and moons.

2. How Does the Calculator Work?

The calculator uses Newton's law of universal gravitation:

Where:

• \( g \) — Surface gravity (m/s²)
• \( G \) — Gravitational constant (6.67430 × 10⁻¹¹ m³ kg⁻¹ s⁻²)
• \( M \) — Mass of the celestial body (kg)
• \( r \) — Radius of the celestial body (m)

Explanation: The equation shows that surface gravity is directly proportional to mass and inversely proportional to the square of radius.

3. Importance of Surface Gravity Calculation

Details: Calculating surface gravity is essential for understanding planetary characteristics, space mission planning, exoplanet studies, and comparing different celestial bodies in our solar system and beyond.

4. Using the Calculator

Tips: Enter mass in kilograms and radius in meters. Both values must be positive numbers. For Earth: mass = 5.972 × 10²⁴ kg, radius = 6.371 × 10⁶ m.

5. Frequently Asked Questions (FAQ)

Q1: Why is surface gravity different on other planets?
A: Surface gravity varies because planets have different masses and radii. Larger mass increases gravity, while larger radius decreases it.

Q2: What is Earth's surface gravity?
A: Earth's surface gravity is approximately 9.8 m/s², though it varies slightly depending on location and altitude.

Q3: How does surface gravity affect weight?
A: Weight = mass × gravity, so the same object will have different weights on celestial bodies with different surface gravities.

Q4: Can this formula be used for any celestial body?
A: Yes, this formula works for any spherical body where mass is evenly distributed, including planets, moons, and stars.

Q5: Why is the gravitational constant so small?
A: The gravitational constant is a fundamental physical constant that reflects the relative weakness of gravity compared to other fundamental forces.