Mercury is the only inner planet other than the Earth that has a significant magnetic field (220 nT). This field, along with the planet's high density and small size relative to the Earth, indicates that it probably has a molten iron core. The magnetic field has two poles, and is tilted in the same direction as Mercury's axis. Mariner 10 observed a shock wave called a "bow shock" in front of the planet, where the planet's magnetic field meets the solar wind.

Mercury is the only inner planet other than the Earth that has a significant magnetic field (220 nT). This field, along with the planet's high density and small size relative to the Earth, indicates that it probably has a molten iron core. The magnetic field has two poles, and is tilted in the same direction as Mercury's axis. Mariner 10 observed a shock wave called a "bow shock" in front of the planet, where the planet's magnetic field meets the solar wind.

Mercury is the only terrestrial planet other than the Earth that has a significant magnetic field (220 nT). This field, along with the planet's high density and small size relative to the Earth, indicates that it probably has a molten iron core. The magnetic field is approximately dipolar and is tilted less than 10 degrees from Mercury's rotation axis. Mariner 10 observed a shock wave called a "bow shock" in front of the planet, where the planet's magnetic field meets the magnetic field carried by the oncomi ng solar wind. Other magnetospheric phenomena have been observed at Mercury.