Венера планетасы: тарихы мен байқаулары

none

Observations of the planet Venus include those in antiquity, telescopic observations, and from visiting spacecraft. Spacecraft have performed various flybys, orbits, and landings on Venus, including balloon probes that floated in the atmosphere of Venus. Study of the planet is aided by its relatively close proximity to the Earth, compared to other planets, but the surface of Venus is obscured by an atmosphere opaque to visible light.

As one of the brightest objects in the sky, Venus has been known since prehistoric times, and as such, many ancient cultures recorded observations of the planet. A cylinder seal from the Jemdet Nasr period indicates that the ancient Sumerians already knew that the morning and evening stars were the same celestial object. The Sumerians named the planet after the goddess Inanna, who was known as Ishtar by the later Akkadians and Babylonians. She had a dual role as a goddess of both love and war, thereby representing a deity that presided over birth and death. One of the oldest surviving astronomical documents, from the Babylonian library of Ashurbanipal around 1600 BC, is a 21 year record of the appearances of Venus. Because the movements of Venus appear to be discontinuous (it disappears due to its proximity to the sun, for many days at a time, and then reappears on the other horizon), some cultures did not immediately recognize Venus as single entity; instead, they assumed it to be two separate stars on each horizon: the morning star and the evening star. The Ancient Egyptians, for example, believed Venus to be two separate bodies and knew the morning star as Tioumoutiri and the evening star as Ouaiti. The Ancient Greeks called the morning star Φωσφόρος, Phosphoros (Latinized Phosphorus), the "Bringer of Light" or Ἐωσφόρος, Eosphoros (Latinized Eosphorus), the "Bringer of Dawn". The evening star they called Hesperos (Latinized Hesperus) (Ἓσπερος, the "star of the evening"). By Hellenistic times, the ancient Greeks identified it as a single planet, which they named after their goddess of love, Aphrodite (Αφροδίτη), Phoenician Astarte, a planetary name that is retained in modern Greek. Hesperos was translated into Latin as Vesper and Phosphoros as Lucifer ("Light Bearer"). Venus was considered the most important celestial body observed by the Maya, who called it Chac ek, or Noh Ek', "the Great Star" and Xux Ek', the Wasp Star. The Maya based their religious calendar partially upon the movements of Venus and monitored its movements closely, including in the daytime. The positions of Venus and other planets were thought to influence life on Earth, so the Maya and other ancient Mesoamerican cultures timed wars and other important events based on their observations. In the Dresden Codex, the Maya included an almanac showing Venus's full cycle, in five sets of 584 days each (approximately eight years), after which the patterns repeated (since Venus has a synodic period of 583.92 days). The Maya were aware of this synodic period, and could compute it to within a hundredth part of a day. indicated a high temperature source (600 K). Strangely, millimetre band observations made by A. D. Kuzmin indicated much lower temperatures. Two competing theories explained the unusual radio spectrum, one suggesting the high temperatures originated in the ionosphere, and another suggesting a hot planetary surface. In September 2020, a team at Cardiff University announced that observations of Venus using the James Clerk Maxwell Telescope and Atacama Large Millimeter Array in 2017 and 2019 indicated that the Venusian atmosphere contained phosphine (PH3) in concentrations 10,000 times higher than those that could be ascribed to any known non biological source on Venus. The phosphine was detected at heights of at least 30 mile (48 km) above the surface of Venus, and was detected primarily at mid latitudes with none detected at the poles of Venus. This could have indicated the potential presence of biological organisms on Venus, however, this measurement was later shown to be in error.

After the Moon, Venus was the second object in the Solar System to be explored by radar from the Earth. The first studies were carried out in 1961 at NASA's Goldstone Observatory, part of the Deep Space Network. At successive inferior conjunctions, Venus was observed both by Goldstone and the National Astronomy and Ionosphere Center in Arecibo. The studies carried out were similar to the earlier measurement of transits of the meridian, which had revealed in 1963 that the rotation of Venus was retrograde (it rotates in the opposite direction to that in which it orbits the Sun). The radar observations also allowed astronomers to determine that the rotation period of Venus was 243.1 days, and that its axis of rotation was almost perpendicular to its orbital plane. It was also established that the radius of the planet was , some less than the best previous figure obtained with terrestrial telescopes. Interest in the geological characteristics of Venus was stimulated by the refinement of imaging techniques between 1970 and 1985. Early radar observations suggested merely that the surface of Venus was more compacted than the dusty surface of the Moon. The first radar images taken from the Earth showed very bright (radar reflective) highlands christened Alpha Regio, Beta Regio, and Maxwell Montes; improvements in radar techniques later achieved an image resolution of 1–2 kilometres.

There have been numerous uncrewed missions to Venus. Ten Soviet Venera probes achieved a soft landing on the surface, with up to 110 minutes of communication from the surface, all without return. Launch windows occur every 19 months.

On February 12, 1961, the Soviet spacecraft Venera 1 was the first flyby probe launched to another planet. An overheated orientation sensor caused it to malfunction, losing contact with Earth before its closest approach to Venus of 100,000 km. However, the probe was first to combine all the necessary features of an interplanetary spacecraft: solar panels, parabolic telemetry antenna, 3 axis stabilization, course correction engine, and the first launch from parking orbit. The first successful flyby Venus probe was the American Mariner 2 spacecraft, which flew past Venus in 1962, coming within 35,000 km. A modified Ranger Moon probe, it established that Venus has practically no intrinsic magnetic field and measured the temperature of the planet's atmosphere to be approximately
The Soviet Union launched the Zond 1 probe to Venus in 1964, but it malfunctioned sometime after its May 16 telemetry session. During another American flyby in 1967, Mariner 5 measured the strength of Venus's magnetic field. In 1974, Mariner 10 swung by Venus on its way to Mercury and took ultraviolet photographs of the clouds, revealing the extraordinarily high wind speeds in the Venusian atmosphere.