Wien's displacement lawWien's displacement law states that the black-body radiation curve for different temperatures will peak at different wavelengths that are inversely proportional to the temperature. The shift of that peak is a direct consequence of the Planck radiation law, which describes the spectral brightness or intensity of black-body radiation as a function of wavelength at any given temperature. However, it had been discovered by Wilhelm Wien several years before Max Planck developed that more general equation, and describes the entire shift of the spectrum of black-body radiation toward shorter wavelengths as temperature increases.
Planck's lawIn physics, Planck's law (also Planck radiation law) describes the spectral density of electromagnetic radiation emitted by a black body in thermal equilibrium at a given temperature T, when there is no net flow of matter or energy between the body and its environment. At the end of the 19th century, physicists were unable to explain why the observed spectrum of black-body radiation, which by then had been accurately measured, diverged significantly at higher frequencies from that predicted by existing theories.
Hubble Space TelescopeThe Hubble Space Telescope (often referred to as HST or Hubble) is a space telescope that was launched into low Earth orbit in 1990 and remains in operation. It was not the first space telescope, but it is one of the largest and most versatile, renowned both as a vital research tool and as a public relations boon for astronomy. The Hubble telescope is named after astronomer Edwin Hubble and is one of NASA's Great Observatories.
École polytechniqueÉcole polytechnique, also known as Polytechnique or l'X liks, is a grande école located in Palaiseau, France. It specializes in science and engineering and is a founding member of the Polytechnic Institute of Paris. The school was founded in 1794 by mathematician Gaspard Monge during the French Revolution and was militarized under Napoleon I in 1804. It is still supervised by the French Ministry of Armed Forces. Originally located in the Latin Quarter in central Paris, the institution moved to Palaiseau in 1976, in the Paris-Saclay technology cluster.
Radiant exitanceIn radiometry, radiant exitance or radiant emittance is the radiant flux emitted by a surface per unit area, whereas spectral exitance or spectral emittance is the radiant exitance of a surface per unit frequency or wavelength, depending on whether the spectrum is taken as a function of frequency or of wavelength. This is the emitted component of radiosity.
Galileo (spacecraft)Galileo was an American robotic space probe that studied the planet Jupiter and its moons, as well as the asteroids Gaspra and Ida. Named after the Italian astronomer Galileo Galilei, it consisted of an orbiter and an entry probe. It was delivered into Earth orbit on October 18, 1989, by , during STS-34. Galileo arrived at Jupiter on December 7, 1995, after gravitational assist flybys of Venus and Earth, and became the first spacecraft to orbit an outer planet.
Soviet space programThe Soviet space program (Kosmicheskaya programma SSSR) was the national space program of the former Union of Soviet Socialist Republics (USSR), active from 1955 until the dissolution of the Soviet Union in 1991. Soviet investigations in rocketry began with the formation of a research laboratory in 1921, but these efforts were hampered by the devastating war with Germany.
Space ShuttleThe Space Shuttle is a retired, partially reusable low Earth orbital spacecraft system operated from 1981 to 2011 by the U.S. National Aeronautics and Space Administration (NASA) as part of the Space Shuttle program. Its official program name was Space Transportation System (STS), taken from a 1969 plan for a system of reusable spacecraft where it was the only item funded for development. The first (STS-1) of four orbital test flights occurred in 1981, leading to operational flights (STS-5) beginning in 1982.
Chinese space programThe space program of the People's Republic of China is about the activities in outer space conducted and directed by the People's Republic of China. It involves the capacity to enter and return from space and ability to engage in space exploration, utilization and governance. The technological roots of the Chinese space program trace back to the 1950s, when, with the help of the newly allied Soviet Union, China began development of its first ballistic missile and rocket programs in response to the perceived American (and, later, Soviet) threats.
Lander (spacecraft)A lander is a spacecraft that descends towards, then comes to rest on, the surface of an astronomical body other than Earth. In contrast to an impact probe, which makes a hard landing that damages or destroys the probe upon reaching the surface, a lander makes a soft landing after which the probe remains functional. For bodies with atmospheres, the landing occurs after atmospheric entry. In these cases, landers may employ parachutes to slow them down enough to maintain a low terminal velocity.
Shenzhou (spacecraft)Shenzhou (, 'ʃɛn'dʒoʊ; see ) is a spacecraft developed and operated by China to support its crewed spaceflight program, China Manned Space Program. Its design resembles the Russian Soyuz spacecraft, but it is larger in size. The first launch was on 19 November 1999 and the first crewed launch was on 15 October 2003. In March 2005, an asteroid was named 8256 Shenzhou in honour of the spacecraft. The literal meaning of the native name 神舟 (p: Shénzhōu; 'ʃɛn'dʒoʊ) is "the Divine vessel [on the Heavenly River]", to which Heavenly River (天河) means the Milky Way in Classical Chinese.
Solar irradianceSolar irradiance is the power per unit area (surface power density) received from the Sun in the form of electromagnetic radiation in the wavelength range of the measuring instrument. Solar irradiance is measured in watts per square metre (W/m2) in SI units. Solar irradiance is often integrated over a given time period in order to report the radiant energy emitted into the surrounding environment (joule per square metre, J/m2) during that time period. This integrated solar irradiance is called solar irradiation, solar exposure, solar insolation, or insolation.
