@beyondearthsky.bsky.social
Reality observer. Astronomy and sci-fi fan. Amateur historian.
My Blog: https://beyondearthsky.blogspot.com
My Blog: https://beyondearthsky.blogspot.com
#OTD in 1901, Werner Heisenberg, a German theoretical physicist, considered one of the founders of quantum mechanics and known for the uncertainty principle, was born. He received the Nobel Prize in Physics in 1932 "for the creation of quantum mechanics".
December 5, 2025 at 8:09 PM
#OTD in 1901, Werner Heisenberg, a German theoretical physicist, considered one of the founders of quantum mechanics and known for the uncertainty principle, was born. He received the Nobel Prize in Physics in 1932 "for the creation of quantum mechanics".
#OTD in 1965, Gemini VII spacecraft was launched. It carried astronauts Frank Borman and Jim Lovell on the 14-day mission – a new record for the duration of a spaceflight. The spacecraft also acted as a rendezvous target for the Gemini VI-A mission.
December 4, 2025 at 9:53 PM
#OTD in 1965, Gemini VII spacecraft was launched. It carried astronauts Frank Borman and Jim Lovell on the 14-day mission – a new record for the duration of a spaceflight. The spacecraft also acted as a rendezvous target for the Gemini VI-A mission.
#OTD in 1639, the first recorded transit of Venus was observed by two English amateur astronomers – Jeremiah Horrocks and William Crabtree. This phenomenon was predicted by Horrocks. The observations allowed Horrocks to estimate the size of Venus and the distance between Earth and the Sun.
December 4, 2025 at 8:45 PM
#OTD in 1639, the first recorded transit of Venus was observed by two English amateur astronomers – Jeremiah Horrocks and William Crabtree. This phenomenon was predicted by Horrocks. The observations allowed Horrocks to estimate the size of Venus and the distance between Earth and the Sun.
#OTD in 2015, ESA's LISA Pathfinder satellite, a technology demonstrator for future spaceborne gravitational wave detectors, was launched.
December 3, 2025 at 10:34 PM
#OTD in 2015, ESA's LISA Pathfinder satellite, a technology demonstrator for future spaceborne gravitational wave detectors, was launched.
#OTD in 1999, Mars Polar Lander crashed on the surface of Mars, most likely due to premature termination of the engine firing prior to the lander touching the surface.
December 3, 2025 at 10:26 PM
#OTD in 1999, Mars Polar Lander crashed on the surface of Mars, most likely due to premature termination of the engine firing prior to the lander touching the surface.
#OTD in 2013, Chang'e 3 with Yutu rover was launched. On Dec. 14 it landed in Mare Imbrium, the first spacecraft to soft-land on the Moon since Luna 24 in 1976.
#OTD in 2020, Chang'e 5 landed in Oceanus Procellarum. The spacecraft collected 1.7 kg of lunar soil and returned to Earth on Dec. 16.
#OTD in 2020, Chang'e 5 landed in Oceanus Procellarum. The spacecraft collected 1.7 kg of lunar soil and returned to Earth on Dec. 16.
December 1, 2025 at 10:04 PM
17-year-old Yuri Gagarin at the foundry department of the Lyubertsy Steel Plant in 1951. He graduated from trade school as a foundryman and later pursued his studies at the Saratov Technical College, where he specialized in tractors.
November 30, 2025 at 8:56 PM
17-year-old Yuri Gagarin at the foundry department of the Lyubertsy Steel Plant in 1951. He graduated from trade school as a foundryman and later pursued his studies at the Saratov Technical College, where he specialized in tractors.
#OTD in 1967, PSR B1919+21, the first known radio pulsar, was discovered at the Mullard Radio Astronomy Observatory in Cambridge, UK, by Jocelyn Bell Burnell. Pusars are now understood to be rapidly rotating, magnetized neutron stars.
November 28, 2025 at 6:44 PM
#OTD in 1967, PSR B1919+21, the first known radio pulsar, was discovered at the Mullard Radio Astronomy Observatory in Cambridge, UK, by Jocelyn Bell Burnell. Pusars are now understood to be rapidly rotating, magnetized neutron stars.
#OTD in 1964, Mariner IV, the first successful mission to Mars, was launched. The spacecraft flew by Mars on July 15, 1965, and returned the first close-up pictures of another planet.
November 28, 2025 at 6:09 PM
#OTD in 1964, Mariner IV, the first successful mission to Mars, was launched. The spacecraft flew by Mars on July 15, 1965, and returned the first close-up pictures of another planet.
#OTD in 1971, Soviet Mars 2 spacecraft entered orbit around Mars, but its lander crashed on the Martian surface. The lander became the first human-made object to reach the surface of Mars.
November 27, 2025 at 9:22 PM
#OTD in 1971, Soviet Mars 2 spacecraft entered orbit around Mars, but its lander crashed on the Martian surface. The lander became the first human-made object to reach the surface of Mars.
Astérix, the first French satellite, was launched #OTD in 1965, on the maiden flight of a Diamant A launch vehicle from Hammaguir, Algeria. With this launch, France has become the third nation to launch a satellite on its own launch vehicle.
beyondearthsky.blogspot.com/2025/11/and-...
beyondearthsky.blogspot.com/2025/11/and-...
November 26, 2025 at 10:49 PM
Astérix, the first French satellite, was launched #OTD in 1965, on the maiden flight of a Diamant A launch vehicle from Hammaguir, Algeria. With this launch, France has become the third nation to launch a satellite on its own launch vehicle.
beyondearthsky.blogspot.com/2025/11/and-...
beyondearthsky.blogspot.com/2025/11/and-...
#OTD 110 y ago "Die Feldgleichungen der Gravitation" paper with field equations formulated by Albert Einstein was presented to the Prussian Academy of Sciences. Einstein’s field equations are a central part of general relativity, describing how matter and energy influence the curvature of spacetime
November 25, 2025 at 7:25 PM
#OTD 110 y ago "Die Feldgleichungen der Gravitation" paper with field equations formulated by Albert Einstein was presented to the Prussian Academy of Sciences. Einstein’s field equations are a central part of general relativity, describing how matter and energy influence the curvature of spacetime
#OTD in 1990, the Keck I Telescope at the W. M. Keck Observatory near the summit of Mauna Kea, Hawaii, at that time the largest optical telescope, saw its first light (the Keck II saw its first light in 1996). Both telescopes have 10-metre aperture primary mirrors with 36 segments.
November 24, 2025 at 1:56 PM
#OTD in 1990, the Keck I Telescope at the W. M. Keck Observatory near the summit of Mauna Kea, Hawaii, at that time the largest optical telescope, saw its first light (the Keck II saw its first light in 1996). Both telescopes have 10-metre aperture primary mirrors with 36 segments.
#OTD in 1969, Apollo 12, the second crewed mission to land on the Moon, successfully returned to Earth. The Command Module, carrying astronauts Charles "Pete" Conrad, Alan L. Bean, and Richard F. Gordon, splashed down in the Pacific Ocean, about 300 miles east of American Samoa.
November 24, 2025 at 1:46 PM
#OTD in 1969, Apollo 12, the second crewed mission to land on the Moon, successfully returned to Earth. The Command Module, carrying astronauts Charles "Pete" Conrad, Alan L. Bean, and Richard F. Gordon, splashed down in the Pacific Ocean, about 300 miles east of American Samoa.
The fourth and final test launch of the Soviet N1 super heavy-lift launch vehicle (N1 7L), carrying Soyuz 7K-LOK spacecraft and a mockup LK lunar module, took place #OTD in 1972. The engine cutoff caused propellant line hammering, rupturing the fuel system, and the rocket failed 107 s after liftoff.
November 23, 2025 at 11:11 PM
The fourth and final test launch of the Soviet N1 super heavy-lift launch vehicle (N1 7L), carrying Soyuz 7K-LOK spacecraft and a mockup LK lunar module, took place #OTD in 1972. The engine cutoff caused propellant line hammering, rupturing the fuel system, and the rocket failed 107 s after liftoff.
#OTD in 2020, Chang'e 5, China’s first lunar sample-return mission, was launched. The spacecraft landed in the Mons Rümker region of Oceanus Procellarum on December 1, and its capsule successfully returned on December 16, 2020, with 1,731 grams of lunar samples.
November 23, 2025 at 10:51 PM
#OTD in 2020, Chang'e 5, China’s first lunar sample-return mission, was launched. The spacecraft landed in the Mons Rümker region of Oceanus Procellarum on December 1, and its capsule successfully returned on December 16, 2020, with 1,731 grams of lunar samples.
Gagarin surrounded by autograph hunters in 1968
Credit: DALMAS/Rex Features
Credit: DALMAS/Rex Features
November 22, 2025 at 8:09 PM
Gagarin surrounded by autograph hunters in 1968
Credit: DALMAS/Rex Features
Credit: DALMAS/Rex Features
Yuri Gagarin poses on a beach with his wife, Valentina, and their daughter Yelena in June 1960, less than a year before he made history as the first person to travel into space.
November 22, 2025 at 8:01 PM
Yuri Gagarin poses on a beach with his wife, Valentina, and their daughter Yelena in June 1960, less than a year before he made history as the first person to travel into space.
#OTD in 1783, the first free flight by humans was made by Jean-François Pilâtre de Rozier and François Laurent, marquis d'Arlandes, aboard a hot air balloon which had been designed and built by the brothers Joseph-Michel and Jacques-Étienne Montgolfier.
beyondearthsky.blogspot.com/2025/11/mont...
beyondearthsky.blogspot.com/2025/11/mont...
November 21, 2025 at 9:56 PM
#OTD in 1783, the first free flight by humans was made by Jean-François Pilâtre de Rozier and François Laurent, marquis d'Arlandes, aboard a hot air balloon which had been designed and built by the brothers Joseph-Michel and Jacques-Étienne Montgolfier.
beyondearthsky.blogspot.com/2025/11/mont...
beyondearthsky.blogspot.com/2025/11/mont...
Edwin Powell Hubble, one of the leading astronomers of the 20. century, was born #OTD in 1889. His discovery in the 1920s that countless galaxies exist beyond our own Milky Way galaxy revolutionized our understanding of the universe and our place within it
beyondearthsky.blogspot.com/2025/11/powe...
beyondearthsky.blogspot.com/2025/11/powe...
November 20, 2025 at 9:40 PM
Edwin Powell Hubble, one of the leading astronomers of the 20. century, was born #OTD in 1889. His discovery in the 1920s that countless galaxies exist beyond our own Milky Way galaxy revolutionized our understanding of the universe and our place within it
beyondearthsky.blogspot.com/2025/11/powe...
beyondearthsky.blogspot.com/2025/11/powe...
#OTD in 1969, astronauts Charles Conrad and Alan Bean visited the Surveyor III spacecraft, which had landed on April 20, 1967, bringing back about 10 kg of parts for later examination on Earth.
November 20, 2025 at 1:43 PM
#OTD in 1969, astronauts Charles Conrad and Alan Bean visited the Surveyor III spacecraft, which had landed on April 20, 1967, bringing back about 10 kg of parts for later examination on Earth.