El twilight It is one of the most magical moments of the day, when the light of the Sun begins to disappear or appear behind the horizon without the Sun being visible yet or no longer. This moment offers a spectacle of colors and shades due to the light refraction in the Earth's atmosphere. But what exactly is twilight and why does it occur? Throughout this article, we will explore in depth the different types of twilight, their duration, and their importance in various disciplines such as astronomy and photography.
What is twilight?
Generally speaking, twilight is the period of time The period between sunset (when the Sun sets below the horizon) and nightfall, or the time between sunrise and the full appearance of the Sun above the horizon. During this interval, sunlight is scattered in the atmosphere, creating a variety of colors ranging from pink to orange or violet. This optical phenomenon occurs due to the diffraction of the Sun's rays by atmospheric particles.
There are two main times of the day when twilight occurs:
- Morning twilight: It occurs just before sunrise, also known as dawn.
- evening twilight: It occurs after sunset, when the Sun is no longer visible, but the horizon still receives some light.
During these moments, daylight is not completely gone, but it is not full either. At this moment, even though the Sun is no longer visible on the horizon, its light continues to indirectly illuminate the sky. The term can also refer to a phase of transition or decline, such as the “twilight of a hero,” in a more metaphorical sense.
Different types of twilight
Twilight can be classified into three categories depending on the amount of sunlight still illuminating the sky:
- Civil twilight: This is the first phase of twilight, during which the Sun is between 0 and 6 degrees below the horizon. During this phase, there is still enough light to carry out daily activities without the need for artificial lighting. People are still able to see objects clearly and the sky is still bright enough.
- Nautical twilight: This occurs when the Sun is between 6 and 12 degrees below the horizon. During this phase, it is no longer possible to clearly distinguish the horizon at sea. However, some stars and planets begin to be visible in the sky.
- astronomical twilight: This is the darkest phase of twilight, which occurs when the Sun is between 12 and 18 degrees below the horizon. At this point, the sky is almost completely dark and only the brightest stars are visible. For astronomers, this is the best time to observe celestial bodies without interference from sunlight.
Twilight light and its impact
El visual effect Twilight is particularly appreciated by photographers and filmmakers for the warm, golden light that illuminates the landscape at these times of day. The hues produced during this phenomenon vary depending on the amount of particles present in the air. This type of light, also known as golden hour light, is ideal for capturing dramatic landscapes and beautiful portraits.
The refraction of the sun's rays is what causes the sky to take on such characteristic colours. The rays of light pass through the Earth's atmosphere, disperse and create shades ranging from violet to red, including orange and pink tones that many people associate with romantic or introspective moments.
Twilight duration
The length of twilight depends on the latitude of your location and the season of the year. In general, this transition phase can last from 20 to 30 minutes in most temperate zones of the planet. However, this duration varies considerably in areas close to the poles or the equator.
- In the regions closest to the polo, like in the Antarctica or Arctic, twilight can last for several weeks due to the Earth's tilt and rotation. There, dawn and dusk only occur once a year.
- In Ecuador, twilight is much shorter and hardly varies throughout the year, as the Sun moves more perpendicular to the horizon.
This fact is of particular importance to stargazers and photographers, who rely on these moments to capture light at its optimal point.
Twilight and Astronomy
For astronomers, astronomical twilight is a key moment, as it marks the beginning of the astronomical night, at which point sunlight no longer interferes with the observation of celestial bodies. Once astronomical twilight ends, total darkness is reached, allowing for close observation of stars, planets, and other celestial bodies. In some remote areas near the poles, such as Iceland, twilight can last for hours or even days during certain times of the year, providing long windows for astronomical observation.
In addition, the upper layers of the atmosphere also play an important role in this phenomenon, as sunlight is refracted and scattered in all directions. This provides an excellent opportunity to observe phenomena such as Aurora borealis in regions near the poles.
Twilight is one of the most fascinating times of the day, whether from a scientific, artistic or simply aesthetic point of view. Not only is it an indicator of the transition between day and night, but it also connects us with nature in a unique and inspiring way.