المملكة: The Earth is approaching the sun next Saturday in an annual astronomical phenomenon

Engineer Majid Abu Zahra explained that the Earth’s orbit around the sun is not completely circular, but rather elliptical, which leads to a change in the distance between the Earth and the sun throughout the year. When the Earth reaches perigee, the distance separating them will reach approximately 147,099,587 kilometers, that is, about five million kilometers closer than what it will be approximately six months later when the Earth reaches apogee, the farthest point from the sun, on July 6, when the distance will then reach approximately 152,081,196 kilometers.

Winter Season

He explained that this difference in distance, although not relatively large, makes the disk of the sun appear apparent. Slightly larger and brighter by approximately 7 percent.

He stressed that the Earth’s proximity or distance from the sun is not the reason for the succession of the four seasons, as this phenomenon is mainly due to the tilt of the Earth’s axis of rotation.

He pointed out that during the winter the North Pole is tilted away from the sun, while it tilts towards it during the summer, while the situation is reversed in the Southern Hemisphere.

The distance between perigee And apogee

As for the difference in the distance between perigee and apogee, it mainly affects the speed of the Earth’s movement in its orbit, as the Earth moves at perihelion at a faster speed, reaching about 30.3 kilometers per second, compared to its speed at aphelion, which makes the winter season in the Northern Hemisphere slightly shorter than the summer season.

Abu Zahra added that the timing of the Earth’s arrival at perihelion in early January is an ideal opportunity for astronomy and solar photography enthusiasts to take pictures of the sun’s disk and compare them later with pictures. It is taken during the month of July at apogee.

At perigee, the Earth is closest to the sun, so its disk appears larger and brighter by about 7 percent compared to the apogee period, which allows a clear visual comparison of the difference in the apparent size of the sun, and helps clarify the relationship between the Earth’s distance from the sun and its effect on visual observation.

He stressed that the accuracy of this comparison requires adherence to several conditions, including using the same telescope or lens, adjusting the same exposure settings, and maintaining the shooting angle. itself, in addition to using a safe solar filter to protect the eyes and the sensor.

A useful educational and scientific experience

Regarding the scientific aspect, he explained that these observations allow measuring the apparent size of the sun accurately, noting the difference in brightness between the periods of perihelion and apogee, and highlighting the relationship between the position of the Earth in its orbit and how the sun appears to the observer, which makes it a useful educational and scientific experience for amateur astronomers and those interested in space sciences.

The attached image shows the planet Earth as seen from space, With the northern half tilted away from the sun and the winter season continues, while the southern half tilts toward the sun where summer prevails.

The image also highlights the Earth’s natural colors, the movement of clouds and weather systems, and different terrains such as deserts and forests, and the contrasting colors of the seas, which also allows monitoring the ozone layer, levels of suspended particles in the atmosphere, high clouds, and plant growth characteristics, in addition to the Earth’s reflectivity to ultraviolet rays.

The satellite. “Discover”

Given the intense brightness of the Earth compared to the darkness of space, such images are taken with short exposure periods ranging between 20 and 100 milliseconds, which explains why the stars do not appear in the background of the images.

Abu Zahra concluded by pointing out that the image was taken by the “Discover” satellite of NASA and the US National Oceanic and Atmospheric Administration (NOAA), from a distance of about 1,393,002 kilometers from Earth.

The satellite was launched on February 11, 2015, and is stationed at the first Lagrange point (L1) between the Earth and the Sun, approximately 1.5 million kilometers away, where gravitational forces provide a relatively stable location outside the Earth’s magnetic environment, which makes it ideal for measuring the solar wind and observing planet Earth.