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Orbital Period Calculator

Orbital Period Equation:

\[ P = 2 \pi \sqrt{\frac{a^3}{G M}} \]

meters
kg
m³/kg·s²

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1. What is the Orbital Period Equation?

The orbital period equation calculates the time it takes for one object to complete an orbit around another object, based on Kepler's Third Law of Planetary Motion. It relates the semi-major axis of the orbit to the mass of the central body.

2. How Does the Calculator Work?

The calculator uses the orbital period equation:

\[ P = 2 \pi \sqrt{\frac{a^3}{G M}} \]

Where:

Explanation: The equation shows that the orbital period increases with the size of the orbit (a³) and decreases with the mass of the central body.

3. Importance of Orbital Period Calculation

Details: Calculating orbital periods is essential for satellite deployment, space mission planning, and understanding celestial mechanics. It helps determine when objects will be in specific positions.

4. Using the Calculator

Tips: Enter the semi-major axis in meters, central mass in kilograms, and gravitational constant (default is 6.67430 × 10⁻¹¹). All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What is the semi-major axis?
A: For circular orbits, it's simply the radius. For elliptical orbits, it's half the longest diameter.

Q2: Can I use this for planets orbiting the Sun?
A: Yes, use the Sun's mass (1.989 × 10³⁰ kg) and the planet's semi-major axis.

Q3: What units should I use?
A: The equation uses SI units: meters, kilograms, and seconds.

Q4: Does this work for all orbits?
A: It works for idealized two-body systems. Perturbations from other bodies may require more complex calculations.

Q5: How accurate is this calculation?
A: It's theoretically exact for point masses or perfect spheres. Real-world factors like oblateness may introduce small errors.

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