locating due south using the constellation, the Southern Cross

In the Southern sky, ancient mariners used the stars that make up the Crux, the Southern Cross, to locate due south.

The Southern Cross is a constellation of 5 stars that can be distinguished from 2 other cross-shaped groups by its size and its two pointer-stars.

Once south was located, the other directions of the compass could be realised.

1 Project an imaginary line along the cross and in a straight line continue on.

2 Then, project another imaginary line that runs perpendicular to the two pointer-stars.

3 Where the two imaginary lines intersect, drop a line vertically down to the horizon. This is due south.

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