Earth’s Rotation and Revolution
September 08, 2021
Photographer: Orazio Mezzio
Summary Author: Orazio Mezzio
The image above shows a composite photo shot during the vernal equinox (March 20, 2020) and the summer solstice (June 21, 2021). The Earth experiences two types of motion, namely rotation and revolution. Rotation is defined as the spinning motion of an object about its axis. Earth rotates around its axis once per day, which causes each day to be 24-hour long. Conversely, revolution is the motion of an object around another object. In the case of Earth, it revolves around the Sun once per year, thus producing the 365-day year.
On the left of the image above, the apparent path of the setting sun (rotation) is shown on the day of the vernal equinox (revolution). During the golden hour, the sky fills with warm colors (rotation). On the right side of the image, the crepuscular rays on the day of the summer solstice (revolution) are clearly visible. It is the blue hour and the sun is far enough below the horizon that only the blue, colder light of the sunset is visible (rotation).
Photo Details: Equinox: Nikon D750; Ob., Nikkor 105mm; Exposure Time: Sun 14 frames, 1/4000 sec – f/29 – iso 100; Church 2 frames, 1/640 sec – f/6.3 – iso 100. Photoshop CC. Image Date: March 20, 2020 ; Solstice: Nikon D750; ob. Signa art 20mm; 1/80 sec. - f/4.5 – iso 100. Image Date June 21, 2021.