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First use of solar power in space. The oldest artificial object still in space. USA Vanguard 1: 4 January 1959: First rocket to reach Earth escape velocity. First spacecraft to attempt to impact the Moon's surface. First artificial object in heliocentric orbit. First detection of solar wind. USSR Luna 1: 17 February 1959: First weather satellite.
The gens (plural gentes) was a Roman family, of Italic or Etruscan origins, consisting of all those individuals who shared the same nomen and claimed descent from a common ancestor. It was an important social and legal structure in early Roman history. [1] [2] The distinguishing characteristic of a gens was the nomen gentilicium, or gentile name.
This timeline of cosmological theories and discoveries is a chronological record of the development of humanity's understanding of the cosmos over the last two-plus millennia. Modern cosmological ideas follow the development of the scientific discipline of physical cosmology .
The principal change was to space leap years differently so as to make the average calendar year 365.2425 days long, more closely approximating the 365.2422-day 'tropical' or 'solar' year that is determined by the Earth's revolution around the Sun. The reform advanced the date by 10 days: Thursday 4 October 1582 was followed by Friday 15 ...
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.
Planetary habitability in the Solar System is the study that searches the possible existence of past or present extraterrestrial life in those celestial bodies. As exoplanets are too far away and can only be studied by indirect means, the celestial bodies in the Solar System allow for a much more detailed study: direct telescope observation, space probes, rovers and even human spaceflight.
5th century BC – Democritus proposes that the bright band in the night sky known as the Milky Way might consist of stars. 4th century BC – Aristotle believes the Milky Way to be caused by "the ignition of the fiery exhalation of some stars which were large, numerous and close together" and that the "ignition takes place in the upper part of the atmosphere, in the region of the world which ...
Ancient history – Aggregate of past events from the beginning of recorded human history and extending as far as the Early Middle Ages or the Postclassical Era. The span of recorded history is roughly five thousand years, beginning with the earliest linguistic records in the third millennium BC in Mesopotamia and Egypt .