Do You Love Twilight? The 3 Stages Explained

View at EarthSky Community Photos. | Soumyadeep Mukherjee shared this composite image from photos taken at Singalila National Park in India in 2024. The bright object is Venus! Soumyadeep wrote: “There are some images, which, after you create, make you happy. This is one of them.” Thank you, Soumyadeep!

Twilight is that magical time of day when a glow pervades the air, even though the sun is below the horizon. Earth’s atmosphere scatters the sun’s rays to create the colors of twilight. On worlds with no atmospheres, such as the moon, the sky falls instantly dark after the sun sets.

And, if you could see twilight from outer space, you’d find that it isn’t marked by a sharp boundary on Earth’s surface. Instead, the shadow line on Earth – sometimes called the terminator line – is spread over a fairly wide area on the surface and shows the gradual transition to darkness we all experience as night falls.

Astronomers – those experts on nighttime – recognize three stages of twilight. Keep reading or watch a video to hear about the intricacies of civil, nautical and astronomical twilight, below.

(Source: earthsky.org)