1. What is Surface Gravity?

Surface gravity (g) is the gravitational acceleration experienced at the surface of an astronomical body. It determines the weight of objects on that planet or moon and influences atmospheric retention and geological processes.

2. How Does the Calculator Work?

The calculator uses the surface gravity formula:

Where:

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

Explanation: The formula shows that surface gravity is directly proportional to the planet's mass and inversely proportional to the square of its radius.

3. Importance of Surface Gravity Calculation

Details: Calculating surface gravity is essential for understanding planetary characteristics, planning space missions, studying exoplanets, and comparing gravitational forces across different celestial bodies.

4. Using the Calculator

Tips: Enter the planet's mass in kilograms and radius in meters. Both values must be positive numbers. For reference, Earth's mass is approximately 5.972 × 10²⁴ kg and radius is about 6,371,000 m.

5. Frequently Asked Questions (FAQ)

Q1: Why is the gravitational constant important?
A: The gravitational constant (G) is a fundamental physical constant that determines the strength of the gravitational force between objects with mass.

Q2: How does surface gravity affect life on a planet?
A: Surface gravity influences biological evolution, atmospheric density, fluid dynamics, and the maximum size of organisms that can develop on a planet.

Q3: What is Earth's surface gravity?
A: Earth's standard gravity is approximately 9.80665 m/s², though it varies slightly depending on location (latitude, altitude, and geological formations).

Q4: Can this formula be used for any celestial body?
A: Yes, this formula applies to any spherical body with mass, including planets, moons, stars, and other astronomical objects.

Q5: How does surface gravity relate to escape velocity?
A: Escape velocity is calculated using the formula \( v_e = \sqrt{\frac{2GM}{r}} \), which is directly related to surface gravity through the same fundamental parameters.