Mass of Mars
| Value | 6.4171e23 kg |
| Status | Measured: ± 1.40e+19 kg (0.000022 relative) |
| Source | NASA planetary fact sheet; GM from JPL DE440 divided by CODATA 2022 G |
| Categories | Astronomicalsolar-systemplanets |
| microgram | 6.4171000e+32 μg |
| milligram | 6.4171000e+29 mg |
| gram | 6.4171000e+26 g |
| kilogram | 6.4171000e+23 kg |
| metric tonne | 6.4171000e+20 t |
| ounce | 2.2635654e+25 oz |
| pound | 1.4147284e+24 lb |
| stone | 1.0105203e+23 st |
| US short ton | 7.0736419e+20 ton |
| grain | 9.9030987e+27 gr |
| unified atomic mass unit (dalton) | 3.8644679e+50 u |
Learning zone
Mars is a tenth of Earth's mass and half its radius, and nearly everything distinctive about the planet follows from that. A small body cools quickly, so its core dynamo shut down some four billion years ago, stripping away the global magnetic field that had shielded the atmosphere from the solar wind; MAVEN has since measured the escaping ions directly. With gravity too weak to hold what remained, surface pressure fell to about 0.6 per cent of Earth's and liquid water became unstable.
The mass is measured to exquisite precision by tracking orbiters and landers — Doppler ranging to the surface stations is good enough to detect the seasonal transfer of carbon dioxide between the atmosphere and the polar caps as a wobble in the planet's rotation.