Suppose you want to photograph the Moon, and you want to know what it will look like in the photo. Given a location on the Earth, and a date/time, this program calculates the orientation of the sunlit side of the Moon with respect to the top of your photo image. It assumes the camera faces directly toward the Moon's azimuth and tilts upward to its altitude angle above the horizon. The angles are defined counterclockwise from the zenith, as shown here:

Culmination

Finds when the Sun, Moon, and planets reach their highest position in the sky on a given date, as seen by an observer at a specified location on the Earth. Culmination is also the moment a body crosses the meridian, the imaginary semicircle in the sky that passes from due north on the horizon, through the zenith (straight up), and then toward due south on the horizon.

Horizon Intersection

This is a more advanced example. It shows how to use coordinate transforms to find where the ecliptic intersects with an observer's horizon at a given date and time.

Lunar Eclipse

Calculates details about the first 10 partial/total lunar eclipses after the given date and time.

Moon Phase Calculator

This example shows how to determine the Moon's current phase, and how to predict when the next few quarter phases will occur.

Positions

Calculates equatorial and horizontal coordinates of the Sun, Moon, and planets.

Rise/Set

Shows how to calculate sunrise, sunset, moonrise, and moonset times.

Seasons

Calculates the equinoxes and solstices for a given calendar year.

Solar Time

An example of how to use the Sun's hour angle to calculate true solar time.

Triangulate

Given the geographic coordinates of two observers, and angular directions they are looking in, determines geographic coordinates of the point they are both looking at. This example demonstrates use of the geoid functions VectorObserver and ObserverVector that convert between geographic coordinates and vectors.

API Reference

Complete documentation for all the functions and types available in the C# version of Astronomy Engine.