🪐 Gravity & Orbit Sim
Launch planets into orbit around the sun! Experiment with mass and velocity to see how celestial bodies dance through deep space.
🚀 Mission Profile
To launch a planet: Click anywhere and drag your mouse/finger away from the starting point. The longer the line, the faster the launch!
- The central yellow star has a massive gravitational pull.
- Planets will speed up as they get closer to the star.
- If a planet hits the sun or flies too far into deep space, it will be destroyed.
- Try creating a stable binary system by launching two planets in opposite directions!
About the Gravity & Orbit Physics Simulator
Have you ever wondered how planets stay suspended in the vast emptiness of space without falling into the sun or drifting away into the dark abyss? The secret lies in a delicate cosmic dance between velocity and gravity. Our free Interactive Gravity & Orbit Simulator allows you to play the role of a cosmic architect, giving you the power to launch your own planets, manipulate mass, and watch the fundamental laws of astrophysics unfold in real-time right in your browser. Whether you are a physics student studying orbital mechanics or a space enthusiast wanting to build a custom solar system, this sandbox provides a fun, risk-free environment for experimentation.
How Orbital Mechanics Work
In our universe, every object with mass exerts a gravitational pull on every other object. The massive central yellow star in this simulator acts as your sun. According to Sir Isaac Newton's Universal Law of Gravitation, the force of this pull depends on two things: the mass of the objects and the distance between them.
- Launching a Planet: When you click and drag your mouse within the tool, you are giving a planet its initial velocity (speed and direction) via a "slingshot" mechanic. If you just drop a planet with no velocity, the sun's gravity will immediately pull it straight down into a fiery collision!
- Achieving Orbit: To achieve a stable orbit, you must launch the planet sideways. The planet naturally wants to fly off in a straight line into deep space due to inertia, but the sun's gravity constantly pulls it inward. When these two forces—the forward momentum and the inward pull—perfectly balance each other out, the planet enters a continuous free-fall around the star, creating an orbit.
- Elliptical Paths: You will notice that most orbits are not perfect circles; they are ovals, or ellipses. As a planet gets closer to the sun (perihelion), the gravitational pull gets stronger, causing the planet to whip around the star at high speeds. As it flings further away (aphelion), it slows down.
Customize Your Solar System
Use the control panel below the simulation to tweak the laws of physics. The "Sun Gravity" slider allows you to increase or decrease the mass of the central star. Watch what happens to your stable orbits when you suddenly double the sun's gravitational pull—your planets might instantly spiral inward and crash! You can also toggle the "Trails" button to map out the exact elliptical paths of your celestial bodies, making it easier to track their orbital periods and understand their trajectory.
Explore More Free Physics & Science Tools
If you enjoyed building your own solar system, FlipNSpin has an entire galaxy of free, interactive science tools for you to explore! Take a tour of our actual cosmic neighborhood with the Interactive Solar System Explorer. Want to see how gravity affects objects here on Earth? Try launching objects in our Projectile Motion Simulator or experiment with swinging motion using the Pendulum Wave Simulator. If you want to dive into the building blocks of matter instead of the stars, check out the Interactive Periodic Table. Browse our complete library of Science Games & Calculators to keep your brain challenged and entertained!