Neptune found 'with the tip of a pen'
A planet calculated first, then found in a single night
From the wobbles in Uranus's orbit, Urbain Le Verrier calculated where an unknown planet should be and wrote to Berlin. Johann Galle got the letter on 23 September 1846 and that same night found Neptune less than a degree from the predicted spot.
Wikipedia (Russian) · Wikipedia (English) · 19th century
Did you know
Galileo saw Neptune 234 years before its discovery and took it for a star. He sketched it in December 1612 and January 1613; it was recognised as a planet only in 1846. Share →
Since its discovery Neptune has gone round the Sun just once. It was found in 1846, and a Neptunian year lasts about 165 Earth years, so the planet celebrated its first 'birthday' in 2011. Share →
Having found Neptune on paper, Le Verrier used the same method to predict a planet that isn't there. In 1859 he proposed Vulcan, near the Sun, to explain Mercury's orbit; people 'saw' it for decades until Einstein explained the orbit in 1915 without it. Share →
Meanwhile around the world (±25 years)
Eastern Europe & Russia
- 1853–1856 Crimean War — 7 years later
- 1861 Emancipation of the serfs in Russia — 15 years later
- 1864 End of the Caucasian War and the Circassian expulsion — 18 years later
- 1867 Alaska Purchase — 21 years later
- 1869 Tolstoy's War and Peace — 23 years later
Middle East
- 1828 Treaty of Turkmenchay — 18 years earlier
- 1839 The Edict of Gülhane opens the Tanzimat — 7 years earlier
- 1839–1842 First Anglo-Afghan War — 7 years earlier
Africa
- c. 1835–1846 The Great Trek — 11 years earlier
- 1847 Liberia declares independence — 1 year later
- 1869 Opening of the Suez Canal — 23 years later
Asia
- c. 1831 Hokusai's Great Wave off Kanagawa — 15 years earlier
- 1839–1842 First Opium War — 7 years earlier
- 1850–1864 Taiping Rebellion — 4 years later
- 1853–1854 Commodore Perry's Black Ships — 7 years later
- 1868 Meiji Restoration — 22 years later
Americas
- 1835 Darwin in the Galápagos — 11 years earlier
- 1838–1839 Trail of Tears — 8 years earlier
- 1846 First public demonstration of ether anaesthesia — same year
- 1846–1848 Mexican–American War — same year
- 1861–1865 American Civil War — 15 years later
Oceania
- 1851 The Australian gold rushes — 5 years later
Alive at the time
- Charles Darwin (aged 37)
- Abraham Lincoln (aged 37)
- Karl Marx (aged 28)
- Queen Victoria (aged 27)
- Fyodor Dostoevsky (aged 25)
- Leo Tolstoy (aged 18)
- Dmitri Mendeleev (aged 12)
- Pyotr Ilyich Tchaikovsky (aged 6)
- Katsushika Hokusai (aged 86)
- Muhammad Ali of Egypt (aged 77)