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 and influences atmospheric retention and planetary features.

2. How Does the Calculator Work?

The calculator uses the surface gravity equation:

Where:

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

Explanation: The equation shows that gravity is directly proportional to mass and inversely proportional to the square of distance from the center.

3. Importance of Surface Gravity Calculation

Details: Surface gravity calculations are essential in astrophysics, planetary science, and space mission planning. They help determine if a body can retain an atmosphere and influence potential habitability.

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 = 6,371,000 m.

5. Frequently Asked Questions (FAQ)

Q1: What's Earth's surface gravity?
A: Approximately 9.807 m/s², though it varies slightly by location due to Earth's rotation and shape.

Q2: How does gravity compare on other planets?
A: Mars has about 3.71 m/s², Jupiter 24.79 m/s², and the Moon 1.62 m/s².

Q3: Why is G so small in value?
A: The gravitational constant is a fundamental physical constant that reflects the relative weakness of gravity compared to other forces.

Q4: Does surface gravity depend on the object's density?
A: Indirectly - two objects with same mass but different radii (and thus densities) will have different surface gravities.

Q5: Can this be used for artificial objects?
A: Yes, but for human-made objects the gravity would be negligible unless they're extremely massive and compact.