The Venera 12 (russian: Венера-12 meaning Venus 12) was an uncrewed

Soviet The Soviet Union,. officially the Union of Soviet Socialist Republics. (USSR),. was a transcontinental country that spanned much of Eurasia from 1922 to 1991. A flagship communist state, it was nominally a federal union of fifteen nation ...

space mission designed to explore the planet

Venus Venus is the second planet from the Sun. It is sometimes called Earth's "sister" or "twin" planet as it is almost as large and has a similar composition. As an interior planet to Earth, Venus (like Mercury) appears in Earth's sky never fa ...

. Venera 12 was launched on 14 September 1978 at 02:25:13 UTC. After separating from its flight platform on 19 December 1978, the Venera 12 lander entered the Venus atmosphere two days later at 11.2 km/s. During its descent, the lander employed

aerodynamic braking Aerobraking is a spaceflight maneuver that reduces the high point of an elliptical orbit (apoapsis) by flying the vehicle through the atmosphere at the low point of the orbit (periapsis). The resulting drag slows the spacecraft. Aerobraking is ...

followed by parachute braking, ending with atmospheric braking. After a nearly one-hour descent, a soft landing was made at 06:30

Moscow time Moscow Time (MSK, russian: моско́вское вре́мя) is the time zone for the city of Moscow, Russia, and most of western Russia, including Saint Petersburg. It is the second-westernmost of the eleven time zones of Russia. It has b ...

(0330 UT) on 21 December. Touchdown speed was 7–8 m/s; landing coordinates are . Continuing for about 110 minutes after touchdown, the lander transmitted data to the flight platform for about 110 minutes until the flight platform, which remained in a

heliocentric orbit A heliocentric orbit (also called circumsolar orbit) is an orbit around the barycenter of the Solar System, which is usually located within or very near the surface of the Sun. All planets, comets, and asteroids in the Solar System, and the Sun i ...

, moved out of range. Venera 11 and 12 carried identical instruments.

Flight platform

The Venera 12 flight platform carried solar wind detectors, ionosphere electron instruments, and two

gamma ray burst In gamma-ray astronomy, gamma-ray bursts (GRBs) are immensely energetic explosions that have been observed in distant galaxies. They are the most energetic and luminous electromagnetic events since the Big Bang. Bursts can last from ten milli ...

detectors – the Soviet-built KONUS and the French-built SIGNE 2. The SIGNE 2 detectors were simultaneously flown on Venera 12 and Prognoz 7 to allow for triangulation of gamma ray sources. Before and after the Venus flyby, Venera 11 and Venera 12 yielded detailed time-profiles for 143 gamma-ray bursts, resulting in the first ever catalog of such events. The last gamma-ray burst reported by Venera 12 occurred on 5 January 1980. Venera 12 used its ultraviolet spectrometer to study comet Bradfield ( C/1979 Y1) on 13 February 1980, and reported spectrophotometric data until 19 March 1980. The list of flight platform instruments and experiments are: * 30–166 nm Extreme UV

spectrometer A spectrometer () is a scientific instrument used to separate and measure spectral components of a physical phenomenon. Spectrometer is a broad term often used to describe instruments that measure a continuous variable of a phenomenon where the ...

* Compound plasma spectrometer * KONUS

Gamma-ray A gamma ray, also known as gamma radiation (symbol γ or \gamma), is a penetrating form of electromagnetic radiation arising from the radioactive decay of atomic nucleus, atomic nuclei. It consists of the shortest wavelength electromagnetic wav ...

burst detector * SNEG Gamma-ray burst detector *

Magnetometer A magnetometer is a device that measures magnetic field or magnetic dipole moment. Different types of magnetometers measure the direction, strength, or relative change of a magnetic field at a particular location. A compass is one such device, o ...

* 4 Semiconductor counters * 2 Gas-discharge counters * 4 Scintillation counters * Hemispherical proton telescope The active phase of the science mission for the flight platform ended in April 1980. Venera 12 is currently in heliocentric orbit, with

perihelion An apsis (; ) is the farthest or nearest point in the orbit of a planetary body about its primary body. For example, the apsides of the Earth are called the aphelion and perihelion. General description There are two apsides in any ellip ...

of 0.69 AU,

aphelion An apsis (; ) is the farthest or nearest point in the orbit of a planetary body about its primary body. For example, the apsides of the Earth are called the aphelion and perihelion. General description There are two apsides in any ell ...

of 1.01 AU,

eccentricity Eccentricity or eccentric may refer to: * Eccentricity (behavior), odd behavior on the part of a person, as opposed to being "normal" Mathematics, science and technology Mathematics * Off-Centre (geometry), center, in geometry * Eccentricity (g ...

of 0.19,

inclination Orbital inclination measures the tilt of an object's orbit around a celestial body. It is expressed as the angle between a Plane of reference, reference plane and the orbital plane or Axis of rotation, axis of direction of the orbiting object ...

of 2.3 degrees and

orbital period 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 ...

of 284 days.

Lander

The Venera 12 descent craft carried instruments designed to study the detailed chemical composition of the atmosphere, the nature of the clouds, and the thermal balance of the atmosphere. These instruments included a

gas chromatograph Gas chromatography (GC) is a common type of chromatography used in analytical chemistry for separating and analyzing compounds that can be vaporized without decomposition. Typical uses of GC include testing the purity of a particular substance, ...

to measure the composition of the Venus atmosphere, instruments to study scattered solar radiation and soil composition, and a device named Groza which was designed to measure atmospheric electrical discharges. Results reported included evidence of lightning and thunder, a high ³⁶Ar/ ⁴⁰Ar ratio, and the discovery of

carbon monoxide Carbon monoxide (chemical formula CO) is a colorless, poisonous, odorless, tasteless, flammable gas that is slightly less dense than air. Carbon monoxide consists of one carbon atom and one oxygen atom connected by a triple bond. It is the simple ...

at low altitudes. Each of the Venera 11 and Venera 12 included landers with a pair of cameras, each of which was designed for color imaging. A design flaw prevented the lens caps from separating, resulting in all cameras failing to capture and return images. The list of lander experiments and instruments are: * Backscatter

nephelometer A nephelometer or aerosol photometer is an instrument for measuring the concentration of suspended particulates in a liquid or gas colloid. A nephelometer measures suspended particulates by employing a light beam (source beam) and a light dete ...

Mass spectrometer Mass spectrometry (MS) is an analytical technique that is used to measure the mass-to-charge ratio of ions. The results are presented as a '' mass spectrum'', a plot of intensity as a function of the mass-to-charge ratio. Mass spectrometry is us ...

– MKh-6411 * Gas

chromatograph In chemical analysis, chromatography is a laboratory technique for the Separation process, separation of a mixture into its components. The mixture is dissolved in a fluid solvent (gas or liquid) called the ''mobile phase'', which carries it ...

– Sigma *

X-ray An X-ray, or, much less commonly, X-radiation, is a penetrating form of high-energy electromagnetic radiation. Most X-rays have a wavelength ranging from 10 picometers to 10 nanometers, corresponding to frequencies in the range 30&nb ...

fluorospectrometer * 360° scanning photometer – IOAV * Spectrometer (430–1170 nm) *

Microphone A microphone, colloquially called a mic or mike (), is a transducer that converts sound into an electrical signal. Microphones are used in many applications such as telephones, hearing aids, public address systems for concert halls and public ...

anemometer In meteorology, an anemometer () is a device that measures wind speed and direction. It is a common instrument used in weather stations. The earliest known description of an anemometer was by Italian architect and author Leon Battista Alberti ...

* Low-Frequency radio sensor * 4

Thermometer A thermometer is a device that temperature measurement, measures temperature or a temperature gradient (the degree of hotness or coldness of an object). A thermometer has two important elements: (1) a temperature sensor (e.g. the bulb of a merc ...

s * 3

Barometer A barometer is a scientific instrument that is used to measure air pressure in a certain environment. Pressure tendency can forecast short term changes in the weather. Many measurements of air pressure are used within surface weather analysis ...

s *

Accelerometer An accelerometer is a tool that measures proper acceleration. Proper acceleration is the acceleration (the rate of change of velocity) of a body in its own instantaneous rest frame; this is different from coordinate acceleration, which is accele ...

– Bizon *

Penetrometer A penetrometer is a device to test the strength of a material. Soil There are many types of penetrometer designed to be used on soil. They are usually round or cone shaped. The penetrometer is dropped on the test subject or pressed against it and t ...

– PrOP-V * Soil Analysis Device * 2 Color Cameras * Small solar batteries – MSB

References

External links

Venera 11 & Venera 12 (NASA)

{{Orbital launches in 1978 Venera program 1978 in spaceflight 1978 in the Soviet Union Derelict landers (spacecraft) Spacecraft launched in 1978

Flight platform

Lander

See also

References

External links