PHYSICS OF A LIVING PLANET

50 ways to understand Earth.

Measure the atmosphere, explore the ocean, study earthquakes and discover orbital motion with no account, no paid APIs and no server calculations.

50Interactive tools

4Science domains

0API requests

ATMOSPHERE

Choose a calculator

Pick a tool from the library.

Calculated result

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Input sensitivity

Calculated by changing the first input, holding others fixed

START END

Method and limits

These are simplified educational models. Do not use their outputs for emergency warnings, engineering certification, navigation, flight operations, medical assessment or safety decisions.

Measurement journal

Saved calculations remain in this browser. No PlanetHeartbeat account or server storage.

Comparison board

Keep up to four outputs side by side. Different physical units are not numerically comparable.

Reference constants

Earth radius6,371 km (mean)

Gravity9.80665 m/s² (standard)

Seawater density1,025 kg/m³ (illustrative)

Earth gravitational parameter398,600.4418 km³/s²

Standard atmosphere1013.25 hPa at sea level

Light travel, 1 AU~8.317 minutes

Constants and approximate models follow conventional introductory Earth-science and physics formulas. Real conditions vary with location, temperature, density and other effects.

Existing public Earth data sources · Read the 50-tool release notes