Mercury's magnetic field
Graph showing relative strength of Mercury's magnetic field. | |
| Discovery | |
|---|---|
| Discovered by | Mariner 10 |
| Discovery date | April 1974 |
| Internal field | |
| Radius of Mercury | 2,439.7 ± 1.0 km |
| Magnetic moment | 2 to 6 × 1012 T•m3 |
| Equatorial field strength | 300 nT |
| Dipole tilt | 0.0° |
| Solar wind parameters | |
| Speed | 400 km/s |
| Magnetospheric parameters | |
| Type | Intrinsic |
| Magnetopause distance | 1.4 RM |
| Magnetotail length | 10–100 RM |
| Main ions | Na+, O+, K+, Mg+, Ca+, S+, H2S+ |
| Plasma sources | Solar wind |
| Maximum particle energy | up to 50 keV |
| Aurora | |
Mercury's magnetic field is approximately a magnetic dipole, apparently global, on the planet of Mercury. Data from Mariner 10 led to its discovery in 1974; the spacecraft measured the field's strength as 1.1% that of Earth's magnetic field. The origin of the magnetic field can be explained by dynamo theory. The magnetic field is strong enough near the bow shock to slow the solar wind, which induces a magnetosphere.