Fizyka Kosmos

Evidence: — • authority: 80

Rotation Period of the Planet Venus

Evidence: — • authority: 80

Distant planet has three suns and a year more than 500 times longer than ours

Evidence: — • authority: 72

Sidereal time ("sidereal" pronounced sy-DEER-ee-əl, sə-) is a system of timekeeping used especially by astronomers. Using sidereal time and the celestial coordinate system, it is easy to locate the positions of celestial objects in the night sky. Sidereal time is a "time scale that is based on Earth's rate of rotation measured relative to the fixed stars". A sidereal day (also known as the sidereal rotation period) represents the time for one rotation about the planet axis relative to the stars. Viewed from the same location, a star seen at one position in the sky will be seen at the same position on another night at the same time of day (or night), if the day is defined as a sidereal day.…

Evidence: — • authority: 72

The orbital period (also revolution period) is the amount of time a given astronomical object takes to complete one orbit around another object. In astronomy, it usually applies to planets or asteroids orbiting the Sun, moons orbiting planets, exoplanets orbiting other stars, or binary stars. It may also refer to the time it takes a satellite orbiting a planet or moon to complete one orbit. For celestial objects in general, the orbital period is determined by a 360° revolution of one body around its primary, e.g. Earth around the Sun. Periods in astronomy are expressed in units of time, usually hours, days, or years. Its reciprocal is the orbital frequency, a kind of revolution frequency, i…

Evidence: — • authority: 72

There have been 47 space missions to the planet Venus (including gravity-assist flybys). Missions to Venus constitute part of the exploration of Venus. The Soviet Union, followed by the United States, have soft landed probes on the surface. Venera 7 was the first lander overall and first for the Soviet Union, touching down on 15 December 1970. Pioneer Venus 2 contained the first spacecraft to land from the United States, the Day Probe. It soft landed on 9 December 1978. The most recent lander was part of the Vega 2 mission, which soft landed on 15 June 1985.

Evidence: — • authority: 72

The terraforming of Venus is the hypothetical planetary engineering procedure that would transform Venus from a planet hostile to life to one that could sustainably host humans and other lifeforms free of protection or mediation. Necessary adjustments to the existing environment of Venus to support human life would require a reduction of the planet's surface temperature and a substantial elimination of the planet's dense atmosphere. At 737 K (464 °C; 867 °F), the surface of Venus is above the melting point of lead. Meanwhile, its 9.2 MPa (91 atm) carbon dioxide and sulfur dioxide atmosphere is almost 100 times as dense as Earth's. These facts are closely interrelated, as Venus's extreme tem…

Evidence: — • authority: 72

Venus is the second planet from the Sun. Similar in size and mass to Earth, Venus has no liquid water, and its atmosphere is far thicker and denser than that of any other rocky body in the Solar System. The atmosphere is composed mostly of carbon dioxide and has a thick cloud layer of sulfuric acid that spans the whole planet. At the mean surface level, the atmosphere reaches a temperature of 737 K (464 °C; 867 °F), making it the hottest planet in the solar system and also a pressure 92 times greater than Earth's at sea level, turning the lowest layer of the atmosphere into a supercritical fluid. From Earth, Venus is visible as a star-like point of light, appearing brighter than any other n…