Why gravity matters
Gravity changes every landing. A light moon feels forgiving. A dense planet feels dangerous. Your ship may still fly well in cruise. The final descent can still become risky. This calculator helps you estimate that risk before touchdown.
Mass and radius drive the result
Planetary mass gives the pull. Radius gives the distance from the center. A body with high mass and small radius can produce severe surface gravity. That combination needs a careful approach. The formula uses Newtonian gravity, so it works for moons, planets, and large bodies.
Surface gravity is not the only value
The tool also estimates gravity at altitude. This is useful during approach planning. Gravity becomes weaker as distance increases. The change may look small near large planets. It may matter more near compact high-g worlds. The chart makes that drop easier to read.
Escape speed and orbit speed
Escape velocity shows how strong the body is overall. A higher value means more energy is needed to leave. Circular orbital speed estimates the speed needed at your selected altitude. These values help compare worlds, even when landing is not planned.
Landing risk score
The landing score combines surface gravity, vertical speed, free-fall speed, and glide load. It is not a flight computer. It is a planning guide. Keep vertical speed low on high-g planets. Avoid steep angles near the surface. Give thrusters time to respond.
Using density checks
Density can reveal unusual bodies. The calculator computes density from mass and radius. If you enter a reference density, it also shows the percentage difference. Large differences may mean the entered units are wrong. They may also show a very dense world.
Commander safety notes
High gravity punishes rushed landings. Use shallow glide paths. Reduce sink rate early. Keep extra altitude while checking terrain. Watch shield strength and thruster response. A careful descent is usually safer than a late correction. Use the exports to save results before exploration trips.