AUTOKINESIS

Staring at a single source of light at night for a long time may make the light appear as it is moving, even though it is actually stationary. As a result, a pilot may mistakenly interpret a star or distant light as another aircraft. There have been many reported cases of such misidentification. This illusion occurs because of small, involuntary eye movements that the brain does not register, and instead interprets as movement of the object itself. To prevent this effect, pilots should avoid prolonged staring and instead shift their gaze regularly.

Let's examine the given options:

A moving light appears to be stationary. → INCORRECT. It is the opposite effect. A stationary light appears to be moving.

A stationary light appears to move. → CORRECT. Staring at a single source of light at night for a long time may make the light appear as it is moving, even though it is actually stationary. This illusion is called autokinesis and is caused due to involuntary eye movements that the brain does not register, and instead interprets as movement of the object itself.

The horizon appears to be tilted due to sloping clouds. → INCORRECT. The horizon is not visible at night so it is not related to this illusion.

You perceive your aircraft to be higher than it actually is. → INCORRECT. This may occur due to black hole effect instead, during an approach to land at night when there is absence of lighted terrain between the aircraft and the runway.