Everything You Never Knew You Wanted to Know About Berlin
Did you know that nearly 171 years ago, on September 23, 1846, no other place on Earth was closer to stars than Berlin? It was here that Johann Gottfried Galle, German astronomer who at the beginning of 1835 joined the team working at Berliner Sternwarte, an observatory built in today´s Berlin-Kreuzberg, where he spent the next 16 years, made a breakthrough discovery: he observed and proved the existence of a new planet, Neptune.
To celebrate Galle´s birthday – the scientist was born on June 9, 1812 – here is a short story of this epic achievement.
On the morning of September 23, 1846 Galle, the discoverer of Kreppring (the inner dark ring) of Saturn as well as of three new comets, received a letter from French mathematician and astronomer, Urbain Le Verrier, who had been studying interesting irregularities of the orbit of Uranus, then the last known planet. However, the results of Le Verrier´s observation of the planet´s movements were at odds not only with his expectations but they were also at odds with Newton´s laws of gravity. Something was causing perturbations in Uranus´ orbit – something that was large enough to influence another planet´s movements.
In his letter to Galle the French scientist pleaded with his German colleague to point his telescope, a massive 9-inch Fraunehofer Refraktor used by the Berlin Observatory and world-famous for its quality, in the direction Le Verrier had established in his lengthy calculations.
Later that day, after getting the necessary permission from the then head of the observatory, Johann Franz Encke (who, interestingly, was celebrating his 55th birthday that very day), Galle began to prepare for the night observation. Assisted by Heinrich Louis d´Arrest, a couple of hours later he saw a massive star only 1° away from the position calculated by Le Verrier. The star was not registered on the Celestial Map of Berlin Academy, one of the best, if not the best, piece of celestial cartography available at the time. The star turned out to be a new planet: Neptune.
Galle never accepted the title of Neptune´s discoverer, attributing the breakthrough, entirely to Le Verrier and his calculations.
As for the old Berlin Observatory, Berliner Sternwarte, designed by Berlin´ chief early 19th-century architect, Karl Friedrich Schinkel, the building was demolished in 1913 to make room for the large Flower Market Hall (Blumengroßmarkthalle), later completely destroyed during WWII. The observatory itself moved to a new location in Potsdam-Babelsberg. Today only the names of the surrounding streets, Besselstrasse and Enckestrasse (both named after other famous Berlin astronomers) remind of this spot´s celestial past.
Here are two stunning images of the planet Neptune and its largest moon, Triton, as well as on its one (colour blue is the result of the strong presence of methane in Neptune´s atmosphere) by Voyager 2, an US space prob launched by NASA in 1977 – it reached the vicinity of Neptune in 1989 (if the distance of 4,591 km can be described as “vicinity”) and is still travelling through space towards the outer reaches of our solar system; Voyager 2 has been flying on its interstellar mission for almost 40 years now!