Two worlds · one reference frame
Compare
Numbers become useful when their definitions stay visible. Dynamic observations are deliberately excluded: this comparison uses version-controlled planetary reference data.
Relative diameter
Two circles, one radius scale
A minimum visible size keeps small worlds selectable. Use the numerical values for exact comparisons.Human-scale differences
Change the reference, not the science
Earth
- 70 kg on Earth
- 70.0 kg-equivalent
- 23 Earth years
- 23.00 local years
- One Earth day
- 100.00% of this world's solar day
Mars
- 70 kg on Earth
- 26.5 kg-equivalent
- 23 Earth years
- 12.23 local years
- One Earth day
- 97.32% of this world's solar day
Accessible reference table
Definitions stay beside the values
| Measure | Earth | Mars |
|---|---|---|
| Mean radius | 6,371 km | 3,389.5 km |
| Mass | 5.972e+24 kg | 6.417e+23 kg |
| Density | 5,513.4 kg/m³ | 3,934 kg/m³ |
| Gravity | 9.80 m/s² · surface-equatorial reference | 3.71 m/s² · surface-equatorial reference |
| Average Sun distance | 1 AU | 1.524 AU |
| Orbital period | 365.3 Earth days | 687 Earth days |
| Sidereal rotation | 23.9 h · prograde | 24.6 h · prograde |
| Solar day | 24 h | 24.7 h |
| Axial tilt | 23.4° | 25° |
| Temperature reference | 15 °C · surface | -65 °C · surface |
| Atmosphere | A nitrogen-oxygen atmosphere that supports liquid surface water and life. | A thin atmosphere dominated by carbon dioxide. |
| Recognized moons | 1 · as of Feb 12, 2026 | 2 · as of Jul 17, 2026 |
| Rings | Earth has no planetary ring system. | Mars has no ring system. |
| Escape velocity | 11.2 km/s | 5 km/s |
| Sunlight travel | 8.3 min | 12.7 min |