1. What is Surface Gravity?

Surface gravity is the gravitational acceleration experienced at the surface of a celestial body. It depends on the body's mass, radius, and is influenced by factors like temperature and rotation.

2. How Does the Calculator Work?

The calculator uses the surface gravity equation:

Where:

• \( G \) — Gravitational constant (6.67430 × 10⁻¹¹ m³/kg·s²)
• \( M \) — Mass of the celestial body (kg)
• \( R \) — Radius of the celestial body (m)
• Temperature adjustment — Accounts for thermal expansion effects

Explanation: The equation calculates basic gravitational acceleration and includes a temperature correction factor to account for changes in density due to thermal expansion.

3. Importance of Surface Gravity Calculation

Details: Surface gravity is crucial for understanding planetary characteristics, space mission planning, and studying exoplanets. It affects atmospheric retention and potential for liquid water.

4. Using the Calculator

Tips: Enter the gravitational constant (default is Earth's), mass in kilograms, radius in meters, and temperature in Celsius. All values must be positive.

5. Frequently Asked Questions (FAQ)

Q1: Why include temperature in gravity calculations?
A: Temperature affects material density through thermal expansion, which can slightly alter a body's effective radius and mass distribution.

Q2: What's Earth's surface gravity?
A: Approximately 9.81 m/s² at sea level, though it varies slightly with latitude and altitude.

Q3: How significant is the temperature effect?
A: For most solid bodies, the effect is small (fractional percentage changes), but becomes important for gas giants or very hot planets.

Q4: Does rotation affect surface gravity?
A: Yes, centrifugal force reduces effective gravity at the equator, but this calculator focuses on the mass-attraction component.

Q5: Can this be used for stars?
A: The basic equation works, but stellar gravity requires additional factors like radiation pressure and relativistic effects.