Mercury

Mercury structure (Large File: 15.6 MB). 

Overall

The visualization for Mercury creates a detailed model with appropriate layers for the inner core, outer core, mantle, crust, exosphere, magnetosphere, and Hill sphere. The visualization includes informative descriptions and properly scales the components.

Inner Core

This shell accurately represents Mercury's inner core as a solid inner core about 1,000 kilometers thick based on MESSENGER findings (2019). The use of a radius fraction of 0.41 for the inner core is reasonable based on current understanding. 

Outer Core

The representation of Mercury's outer core as a liquid metallic layer that generates the planet's weak magnetic field is accurate, as is the approximate thickness of 1074 km. The radius fraction of 0.85 is consistent with our understanding of Mercury's structure.

Mantle

The description of Mercury's mantle correctly indicates it's significantly thinner than Earth's (about 331 kilometers thick) and mentions recent research suggesting possible diamond content formed from carbon-rich material under pressure. This is consistent with current theories.

Crust

The representation of Mercury's crust as heavily cratered and resembling Earth's Moon is accurate. The description correctly notes its thinness (about 35 km) compared to Earth's and includes the theory about possible diamond content from meteorite impacts on a graphite-rich surface.

Atmosphere/Exosphere

The description of Mercury's exosphere as extremely thin and composed mostly of oxygen, sodium, hydrogen, helium, and potassium atoms is accurate. The explanation that these atoms are blasted off the surface by solar wind and micrometeoroid impacts is correct.

We have included description of the sodium tail extending up to 24 million kilometers (approximately 10,000 Mercury radii), which is scientifically accurate and an important feature of Mercury's exosphere.

Magnetosphere

The description of Mercury's magnetosphere is accurate, noting it's surprisingly active despite Mercury's small size and slow rotation, but significantly weaker and smaller than Earth's. 

Our descriptions about the sunward distance to the bow shock (1.4-2.0 Mercury radii), the equatorial radius of the magnetopause (1.1-1.5 radii), and the polar radius (0.8-1.2 radii) align with observations from the MESSENGER and BepiColombo missions.

Hill Sphere

Our description of Mercury's Hill sphere is accurate, noting that it's the region where Mercury's gravity dominates over the Sun's tidal forces. The visualization uses a radius fraction of 94.4 Mercury radii. This is the most reliable astronomical data.

The Hill sphere is an important concept that explains why Mercury doesn't have natural satellites - any potential moon would need to orbit well within Mercury's relatively small Hill sphere to remain gravitationally bound, which is difficult given Mercury's proximity to the Sun's overwhelming gravitational influence.