Monday, February 13, 2023

Walking in the moonlight


No, this isn't taken on the day. This was actually shot 5:24 am a few days ago. It shows how far current generation of mobile phone's cameras has evolved. I couldn't dream of this few years ago. 


Moonlight consists of mostly sunlight (with little Earthlight) reflected from the parts of the Moon's surface where the Sun's light strikes.


The intensity of moonlight varies greatly depending on the lunar phase, but even the full moon typically provides only about 0.05–0.1 lux illumination.[2] When a full Moon around perigee (a "supermoon") is viewed around upper culmination from the tropics, the illuminance can reach up to 0.32 lux.[2] From Earth, the apparent magnitude of the full Moon is only about 1⁄380,000 that of the Sun.


The Moon's bond albedo is 0.12,[3] meaning only 12% of incident sunlight is reflected from the lunar surface. Moonlight takes approximately 1.26 seconds to reach Earth's surface. Scattered in Earth's atmosphere, moonlight generally increases the brightness of the night sky, reducing contrast between dimmer stars and the background. For this reason, many astronomers usually avoid observing sessions around a full moon.


My other blogs:

Roadscape Photography
Chevrolet El Camino 1970
Life @ Loimaa, mostly Finnish

Monday, February 6, 2023

Sunset is always magnificent

At least when there aren't too much clouds to cover it completely. 




The time of sunset is defined in astronomy as the moment when the upper limb of the Sun disappears below the horizon. Near the horizon, atmospheric refraction causes sunlight rays to be distorted to such an extent that geometrically the solar disk is already about one diameter below the horizon when a sunset is observed.

Sunset is distinct from twilight, which is divided into three stages. The first one is civil twilight, which begins once the Sun has disappeared below the horizon, and continues until it descends to 6 degrees below the horizon. The second phase is nautical twilight, between 6 and 12 degrees below the horizon. The third phase is astronomical twilight, which is the period when the Sun is between 12 and 18 degrees below the horizon. Dusk is at the very end of astronomical twilight, and is the darkest moment of twilight just before night. Finally, night occurs when the Sun reaches 18 degrees below the horizon and no longer illuminates the sky.


My other blogs:

Roadscape Photography
Chevrolet El Camino 1970
Life @ Loimaa, mostly Finnish