Vaughan of Arizona saw this incredible triangular shadow from
the top of Mauna Kea, 4205m (13,800ft), the highest peak of the Hawaiian
Islands. The peak has a roughly triangular shape but the shadow cast
through the air owes its angular shape more to perspective.
In the sky, faint anticrepuscular
rays radiate from the antisolar point marked by the mountain
shadow's tip. Image ©Josh vaughan, shown with