5.1 The PlanetPlot Function
PlanetPlot is useful for showing a Mercator projection of the surface of a planet. In the case of the Earth, the shadow of the Moon is also shown during a solar eclipse. Features on the surface of Mars and the clouds on Jupiter are displayed with this function as well.
Plotting surface features in two dimensions.
A typical use of PlanetPlot is to plot the shadow of the Moon on the surface of the Earth during a solar eclipse.
Here PlanetPlot creates a plot of part of the 1994 solar eclipse that passed across South America. The region of totality is shown with a small black dot, and the region where a partial eclipse is visible is indicated by the shadow around that dot. The darker region over Asia and the Pacific is the night side of the Earth.
Here is a three-dimensional plot of the same eclipse in 1994.
When using PlanetPlot to display the state of the Earth during a solar eclipse, you will notice additional gray areas that represent the shadow of the Moon. The shadow is split into two distinct regions. The center part of the shadow is where the Sun is totally blocked out by the Moon, and its size is typically about 100km across. This center portion sweeps across the surface of the Earth at roughly 2000km/hour, and so any given point is in darkness for at most a few minutes. PlanetPlot represents this total eclipse region as a very small black dot.
The outer part of the shadow is where the Sun is only partly blocked by the Moon, and is very much larger at approximately 7,000km in diameter, or about half the diameter of the Earth itself. PlanetPlot shows this partial eclipse region as a slightly grayed out area surrounding the black dot signifying total eclipse.
Plots of other planets can be produced as well.
This is a two-dimensional map of Mars, with the shaded region away from the Sun not shown.
Shading -> False,
FeatureLabels -> True];
By default the full Mercator projection of the planet is shown, extending from longitude -180 to 180, and from latitude -90 to 90. You can use the option PlotRange to zoom into a smaller region.