Crepuscular rays are sunrays in twilight skies

Crepuscular rays are sun rays that appear during twilight skies, specifically around sunrise or sunset when the sun is below the horizon. These rays are more noticeable when the sky is darker, creating a higher contrast between light and dark. The sun's rays are actually parallel, but they appear to fan out due to linear perspective, much like how parallel train tracks seem to converge in the distance.

Dust, smoke, or water droplets in the air scatter the light, making these rays visible. The darker streaks alongside the sunrays are caused by shadows, either from the terrain or clouds that block the sunlight. Sometimes, these obstructions are below the horizon from your point of view, making the darker rays less apparent.

When these rays extend from behind a cloud toward the ground, they are often referred to as Jacob's Ladder, a term derived from a biblical story. Although the rays seem to converge, they are actually parallel and can be traced across the sky to the point on the horizon opposite the sunset. It's worth turning around to spot the less noticeable anticrepuscular rays, which create a similar illusion to standing on train tracks with parallel lines converging in the distance.