NightHemisphere

NightHemisphere[]

is a two-dimensional GeoGraphics primitive that represents the half of the Earth currently in darkness.

NightHemisphere[datespec]

represents the night half of the Earth for the specified date.

Details

  • datespec can be a DateObject or a string that resolves to a date.
  • A date without explicit time zone is assumed to use $TimeZone.

Examples

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Basic Examples  (2)

Shade the part of the Earth currently at nighttime:

Show the unilluminated part of the Earth on the summer solstice, using red lines to denote the Arctic and Antarctic Circles:

Use a different projection:

Scope  (3)

NightHemisphere[] gives a plot for the current date and time:

Using Now explicitly gives the same result:

Illustrate changes in the unilluminated hemisphere at different times of day and year:

Specify dates in other formats:

Properties & Relations  (2)

The terminator line separates the day and night hemispheres:

For a spherical model of the Earth, the night hemisphere is a geo disk:

The true night hemisphere and approximate darkness geo disk differ slightly when using an ellipsoidal model of the Earth:

Introduced in 2014
 (10.0)