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First Telescope
The earlier working telescopes appeared in 1608 and are credited to Hans Lipphershey. This is important because without a working telescope, the further discoveries of space might have never been made because nobody would know, let alone be able to see, what was beyond our Earth. -
Galileo Proves that Earth Orbits, not is Orbited
Galileo Galilei publishes Sidereus Nuncius describing the findings of his observations with the telescope he built. These include spots on the Sun, craters on the Moon, and four satellites of Jupiter. Proving that not everything orbits Earth, he promotes the Copernican view of a Sun-centered universe. -
The Idea of the Reflector Telescope is Born
Scottish astronomer James Gregory describes his "gregorian" reflecting telescope, using parabolic mirrors instead of lenses to reduce chromatic aberration and spherical aberration, but is unable to build one -
Uranus is Discovered
Amateur astronomer William Herschel discovers the planet Uranus, although he at first mistakes it for a comet. Uranus is the first planet to be discovered beyond Saturn, which was thought to be the most distant planet in ancient times -
Spectroscopy Begins
Joseph von Fraunhofer builds the first accurate spectrometer and uses it to study the spectrum of the Sun's light. He discovers and maps hundreds of fine dark lines crossing the solar spectrum. In 1859 these lines are linked to chemical elements in the Sun's atmosphere. Spectroscopy becomes a method for studying what stars are made -
Sputnik 1 Launches
Russia launches the first artificial satellite, Sputnik 1, into orbit, beginning the space age. The US launches its first satellite, Explorer 1, four months later. -
First Man In Space
takes the lead in the space race as Yuri Gagarin becomes the first person to orbit Earth in April. NASA astronaut Alan Shepard becomes the first American in space a month later, but does not go into orbit. John Glenn achieves this in early 1962. -
Neil Armstrong on the Moon
The US wins the race for the Moon, as Neil Armstrong steps onto the lunar surface on July 20. Apollo 11 is followed by five further landing missions, three carrying a sophisticated lunar rover vehicle. -
The Discovery of Black Holes.
Charles Thomas Bolton was the first astronomer to present irrefutable evidence of the existence of a black hole -
Probe Launch to Study Planets and the Kuiper Belt
(August 20) The Voyager 2 space probe launched by NASA to study the Jovian system, Saturnian system, Uranian system, Neptunian system, the Kuiper belt, the heliosphere and the interstellar space. (September 5) The Voyager 1 space probe launched by NASA to study the Jovian system, Saturnian system and the interstellar medium. -
First Of NASA's Reusable Space Shuttles Launches
Columbia, the first of NASA's reusable space shuttles, makes its maiden flight, ten years in development, the shuttle will make space travel routine and eventually open the path for a new International Space Station. -
First Infared Space Satellite Launches
The first infrared astronomy satellite, IRAS, is launched. It must be cooled to extremely low temperatures with liquid helium, and it operates for only 300 days before the supply of helium is exhausted. During this time it completes an infrared survey of 98% of the sky. -
The Megellan Probe is Launched
The Magellan probe, launched by NASA, arrives at Venus and spends three years mapping the planet with radar. Magellan is the first in a new wave of probes that include Galileo, which arrives at Jupiter in 1995, and Cassini which arrives at Saturn in 2004. -
Hubble is Launched
The Hubble Space Telescope, the first large optical telescope in orbit, is launched using the Space Shuttle, but astronomers soon discovered that it is crippled by a problem with its mirror. A complex repair mission in 1993 allows the telescope to start producing spectacular images of distant stars, nebulae, and galaxies. -
New Definition of Planet
International Astronomical Union (IAU) adopted a new definition of planet. A new distinct class of objects called dwarf planets was also decided. Pluto was redefined as a dwarf planet along with Ceres and Eris, formerly known as (2003) UB313. Eris was named after the IAU General Assembly in 2006.
