hämarust

Hämarust is a Estonian word that translates to "twilight" or "dusk" in English. It refers to the period of time between daylight and full darkness, or between full darkness and daylight. This transitional phase occurs twice a day: in the evening as the sun sets, and in the morning as the sun rises.

During hämarust, the sky is not fully illuminated by direct sunlight, nor is it completely dark. The intensity of light gradually decreases in the evening and increases in the morning. This phenomenon is caused by the scattering of sunlight in the Earth's atmosphere. As the sun dips below the horizon, its rays pass through a greater thickness of the atmosphere, scattering shorter wavelengths of light (blues and violets) and allowing longer wavelengths (reds and oranges) to become more visible, creating the characteristic colors of twilight.

There are generally considered to be three stages of twilight: civil twilight, nautical twilight, and astronomical twilight. Civil twilight is the brightest, occurring when the sun is up to six degrees below the horizon. Nautical twilight is dimmer, when the sun is between six and twelve degrees below the horizon, and allows for navigation by stars. Astronomical twilight is the darkest, when the sun is between twelve and eighteen degrees below the horizon, and is the point at which the sky is considered fully dark for astronomical observations. The precise duration and appearance of hämarust vary depending on the latitude, time of year, and weather conditions.