pale blue dot
On April 30, 1897, British physicist and Nobel Laureate in Physics, Sir Joseph John Thomson (commonly known as J. J. Thompson, 18 December 1856 – 30 August 1940) announced the existence of electrons. Thompson called the particles “corpuscles”, meaning “small bodies”, but later scientific community preferred the name electron which had been suggested by the …
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On April 24, 1990, Hubble Space Telescope was launched into Low Earth Orbit (LEO) from the space shuttle Discovery (STS-31). It orbits the Earth at an altitude of about 350 miles (560 kilometers). For comparison, the International Space Station (ISS) maintains an orbit with an altitude of between 205 and 270 miles (330 and 435 …
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On April 22, 1970, the first Earth Day was celebrated. This date marks the birth of the modern environmental movement.
The first transcontinental video call was performed on April 20, 1964, through an AT&T Picturephone Mod I, a device consisting of a telephone handset and a small, matching TV.
On April 19, 1971, the world’s first space station, Salyut 1 (DOS-1, also referred to in documents as “Product 17K” or No. 121) was launched into space by the Soviet Union.
On April 16, 1972, the huge, 363-feet (110.6 meters) tall Apollo 16 (Spacecraft 113/Lunar Module 11/Saturn V SA-511, see notes 1) space vehicle was launched from Pad A, Launch Complex 39, Kennedy Space Center, Florida, at 12:54 p.m. EST. Crewed by Commander John W. Young, Lunar Module Pilot Charles Duke (see notes 2), and Command Module Pilot …
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On April 14, 1932, the English physicist Sir John Douglas Cockcroft and the Irish physicist Ernest Walton split the atom for the first time using the nuclear particle accelerator they built, also the first particle accelerator in history. Cockcroft and Walton won the 1951 Nobel Prize in Physics for their “work on the transmutation of …
On April 12, 1961, Soviet cosmonaut Yuri Gagarin became the first human to fly into space. His vehicle, Vostok 1 circled Earth at a speed of 27,400 km/h (17,025 mph) with the flight lasting 108 minutes. Vostok’s reentry was controlled by a computer, and Gagarin wasn’t controlling the spacecraft, unlike the early U.S. human spaceflight …
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On April 12, 1981, NASA launched the first Space Shuttle mission, STS-1 (Space Transportation System-1), into space. The first reusable orbiter, Space Shuttle Columbia orbited Earth 37 times on its maiden voyage and returned on April 14, 1981, 54.5 hours later its launch.
On April 11, 1986, with about 63 million kilometers (39 million miles), Halley’s Comet made its closest approach to Earth on its outbound journey (while moving away from the Sun).
