Explore Orbit & Gravity through experimentation.

Explore the lab

What you can explore

• Mass and radius

  Change central mass or initial radius to compare gravity, circular target speed and circular period.

• Initial speed and orbit shape

  Choose circular, slow or escape-like launches to inspect changing position, speed and trail.

• Forces and energy

  Display velocity/gravity vectors and radius, then inspect total orbital energy calculated from speed and radius.

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The model

Formula and underlying model

M, m

Central and orbiting masses (kg in SI; model units otherwise)

r

Separation from central body (m in SI; model units otherwise)

G

Gravitational constant: 6.67430×10⁻¹¹ in SI; 1 educational (m³/(kg·s²) in SI)

v_c, T_c

Circular target speed and circular period (m/s; s in SI)

F, g, E

Gravity force, acceleration and total energy (N; m/s²; J in SI)

Fixed-central-mass Newtonian educational model, not an n-body simulation. Render coordinates are normalized. Ten playback seconds represent four initial circular periods; a collision cutoff stops the integration near the center.

Learning outcomes

What you’ll learn