One hundred seventy-five years ago, on September 23, 1846, the German astronomer Johann Gottfried Galle discovered the eighth and farthest planet in the solar system, Neptune.

Even the ancient astronomers who were the first to spy on celestial phenomena distinguished between the stars that seemed to be motionless and the planets that changed their positions. From their geocentric viewpoint, the Earth was the center of the universe, and the five known planets are Mercury, Venus, Mars, Jupiter and Saturn. With the spread of the heliocentric worldview, the Earth also ranked sixth among the planets. The seventh, discovered by German-Englishman William Herschel, Uranus in 1781, was observed several times with the naked eye, but was thought to be a star. (Stars are celestial bodies that produce fusion with their own light, while planets reflect the light of their central star, their emitted radiation is negligible.)

Galileo had already observed Neptune, invisible to the naked eye, in 1612, but it was thought to be a permanent star.

It also appeared on the star chart of Joseph Lalande, who spotted it in different places twice in 1795, so his first measurement was considered incorrect. From the irregularities (orbital perturbations) in the newly discovered motion of Uranus, which intensified in 1821-22, as we now know when Uranus and Neptune coexist, in 1834 the English astronomer Thomas J. New planet. However, the head of the royal constellation, George Biddle Airy, did not dwell on his assumption, nor did he make any observations to substantiate the calculations when John Cush Adams, in 1845, calculated the locations of the unknown planet from motion disturbances. Therefore, in Britain, many blame Airy for making them the only English companions in the discovery of Neptune.

The French Urbain Le Verrier, completely independent of Adams, also calculated disturbing celestial body data from differences in the calculated and observed motion of Uranus. His thesis, in which he also presented the planet’s expected size and location, was submitted to the French Academy on August 31, 1846. As the Paris Observatory put off observations, the impatient Le Verrier also sent a letter to Berlin containing his calculations. Johann Gottfried Galle measured it on the day the letter was received, more precisely on the night of September 23, 1846, with his pupil Louis Darst, and found the supposed orb one degree away from the specified place. After being moved the next day, it was confirmed that they had found a new planet, not a star.

Thus, the glory of the discovery officially belongs to Le Verrier and Gale, since Adams’ correct accounts were not verified by observation.

It found its third planet in solar system mass, fourth in diameter, and first in theory, as French mathematician François Arago noted, discovered by Le Verrier with “the tip of a feather,” a mathematical-based discovery that dramatically proves Newton’s law of gravitation. At the suggestion of Le Verrier, the new celestial body was named after the Roman god of the sea, Neptune, so that – with the exception of Earth – all the planets in our solar system bear the names of the gods of Greco-Roman mythology. Of the eight planets, four rocky planets (Mercury, Venus, Earth, and Mars) orbit the inner solar system, and four gaseous or giant planets (Jupiter, Saturn, Uranus, and Neptune) orbit the outside.

Studying the motion of Uranus also revealed the rotation of Pluto in the Kuiper belt behind Neptune in 1930, which was then considered the ninth planet. However, the concept of a planet was revised by the International Astronomical Union in 2006: according to the new definition, it is a celestial body revolving around the Sun, having sufficient mass to be hydrostatically balanced, nearly spherical, and dominant in its orbit, that is, cleared of other celestial bodies. Pluto no longer meets the new conditions, so it was “degraded” and placed in the category of a newly created dwarf planet. Pluto is the most famous example of a type of celestial body that travels between a planet and an asteroid, and the plutoids (the dwarf planets that orbit around Neptune) also include Eris, Haumea, and Makemake. The only non-plutodic dwarf planet in the Solar System is Ceres, located in the asteroid belt between Mars and Jupiter.

Neptune, marked by a trident, is the farthest planet in the solar system. Its average orbital distance from the Sun is 4.5 billion km, 30 times farther from Earth, and its diameter is 49,500 km, almost four times the distance from Earth. It has orbited the Sun for 165 years, so it has only circumnavigated the center of our star system once since its discovery. Its axis of rotation deviates from the vertical by 29.6 degrees, which makes one revolution in 16 hours and 5 minutes. The bluish color of its atmosphere is caused by methane, but it also contains hydrogen, helium and ethylene, and its core contains ice and rocks. It weighs 17.1 times and has a volume of 57 times the size of the Earth. Density (1.76 g/cm3) is higher than other gaseous planets, with a surface temperature of about minus 220 degrees Celsius. It also has some internal energy because it radiates more heat than it receives from the sun. Its atmosphere is changing very quickly, and by 1994, the Great Dark Spot, discovered during a 1989 visit by the Voyager 2 spacecraft, which blew the fastest winds in the solar system at 2,200 km / h, was gone. Voyager 2 also discovered Neptune’s magnetic field and faint ring system. The three brightest of his episodes are Galle, Adams and Le Ferrer.

The largest of Neptune’s 14 known moons is the first, Triton, discovered in 1846, and the second, Nerida, discovered in 1949. In addition to the six moons found by Voyager-2, five were recorded using ground-based telescopes in 2002- 2003, and another in 2013 using Hubble Space Telescopes.

If you want to know something about similar things, you can like it HVG Tech’s Facebook page, which also deals with scientific issues.

The number of editorial boards independent of power is steadily declining, and those that do still exist are trying to stay afloat under growing headwinds. At HVG, we persevere and never give in to pressure, bringing local and international news every day.

That’s why we ask you, our readers, to support us! We promise to continue to give you the best we can!