The Venus probe is used to detectVenusArtificialspacecraft, including flyers passing near VenusTrackerDetected during falling or landing on the surface of VenusLander, and those who can move freely on the surface of Venus in the futurerover andManned spacecraftEtc.
Phase diagram of the orbit of the Earth, Venus and the Sun
Venus (Greek: Aphrodite; Babylonian: Ishtar) is the goddess of beauty and love. The reason why it is so named may be that for the ancient people, it is the brightest planet among the known planets.(There are also some objections that Venus is named because its surface is like that of a woman.)
Venus has been known since prehistory.Apart from the sun and moon, it is the brightest one.LikeMercuryIt is usually considered to be composed of two independent stars: the morning star is called Eosphorus, and the evening star is called Hesperus. Greek astronomers know this better.
Since Venus is an inner planet, if you use a telescope to observe it from the Earth, you will find that it has a phase change.Galileo's observation of this phenomenon is in favor of Copernicus'sHeliocentric theoryImportant evidence.
In the 1960s, the Mariner 2 and Mariner 5 spacecraft of NASA obtained the composition, pressure and density of Venus' atmosphere through their radio occultation experiments.In 1978, Pioneer Venus Orbiter (Pioneer Venus Orbiter, namely Pioneer Venus 1) and Pioneer Venus 2 (Pioneer Venus Multi detector) were successively launched to measure the atmosphere, cloud layer, magnetic field and surface of Venus.On May 4, 1989, the United States launched the Magellan detector, which carried synthetic aperture radar (SAR)an altimeter(ALT) andradiometer(RAD), surveying and mapping 98% surface map and 95% gravity field map of Venus, with a resolution of about 100m.The United States flew to JupiterGalileo probe And Cassini flying to Saturnhuygens probe Venus was also detected when flying over Venus.On November 9, 2005, the European Space Agency (ESA) launched the Venus Express probe, which carried seven scientific instruments. The exploration data will reveal some mysteries of Venus' atmosphere, clouds and surface, such as whether there is active volcanic activity, the characteristics of Venus' atmosphere, atmospheric circulation, the relationship between atmospheric structure and composition and heightThe relationship between atmosphere and surface, and the space environment of Venus.[1]
Structural characteristics of Venus
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The rotation of Venus is very unusual. On the one hand, it is very slow (Venus day is equivalent to 243 Earth days), on the other hand, it is inverted.In addition, the rotation period of Venus is synchronized with its orbital period, so when it reaches the nearest point with the Earth, the side of Venus facing the Earth is always fixed.Whether this is a resonance effect or just a coincidence is unknown.(In fact, the reason is that Venus isTidal locking , just like the moon to the earth, only one side is always right)[1]
Venus is sometimes called the sister star of the earth, and they are very similar in some aspects:
1. Venus is slightly smaller than the Earth (95% of the Earth's diameter, 80% of the Earth's mass);
2. There are some ring-shaped mountain passes on the relatively young surface;
3. Their density is very similar to that of chemical composition.
Because of these similarities, it is sometimes thought that Venus may be very similar to the Earth under its thick clouds, and there may be life.Unfortunately, many in-depth studies on Venus show that Venus is fundamentally different from Earth in many aspects.
Venus has an atmospheric pressure of 90 standard atmospheres (equivalent to the pressure at the depth of 1 km of the Earth's ocean). The atmosphere is mostly composed of carbon dioxide, and there are also several layers of clouds thousands of meters thick composed of sulfuric acid.These clouds block our view of the surface of Venus, making it very blurred.This dense atmosphere has also produced the greenhouse effect, causing the surface temperature of Venus to rise by 400 degrees, more than 740 Kelvin (enough to melt the lead bars).Venus is naturally hotter than Mercury, although Venus is twice as far from the sun as Mercury.There is a strong wind at the top of the cloud layer, about 350 kilometers per hour, but the surface wind speed is very slow, less than several kilometers per hour.
Venus may have had a lot of water like the Earth, but it was evaporated and dissipated, making it very dry now.The earth would have the same luck if it were closer to the sun.We will know why the basic conditions are so similar but there are so different phenomena.
Most of the surface of Venus is composed of slightly undulating plains, and there are several broad depressions: Atalanta Planitia,Guinevere Planitia, Lavinia Planitia；There are also two big highlands: Ishtar Terra, which is as big as Australia in the northern hemisphere, and Aphrodite Terra, which is as big as South America along the equator.Ishtar is mainly composed of Lakshmi Planum Plateau, surrounded by the highest mountains on Venus, including the giant mountain Maxwell Montes.
On February 12, 1961, the former Soviet Union launchedVenus 1 detectorHowever, the communication was interrupted when it was 7.56 million kilometers away from the earth, and the detection results could not be obtained.Launched on June 12, 1967Venus 4 detectorAfter about 350 million kilometers of flight, it entered the atmosphere of Venus and successfully landed on the surface of Venus.Because the pressure and temperature of Venus atmosphere are much higher than expectedlanding moduleDamaged and failed to send back the Venus detection results.On December 15, 1970, Venus 7 made a soft landing on Venus and successfully transmitted data such as Venus surface temperature.The measured surface temperature of Venus is 447 degrees Celsius, the pressure is 90 atmospheres, and the atmospheric density is about 100 times that of the Earth.Since then, the former Soviet Union has launched nine moreVenus probe。Venus 9 and 10 took a panoramic picture of Venus on the surface of Venus, showing the face of Venus to people for the first time;Venus 13 and 14 took four color photos of the surface of Venus. From these photos, it is found that the surface of Venus is covered with brown sand, and the rock structure is like smooth layered plates;Venus 15 and 16 conducted a comprehensive survey of the surface of Venus through radar, and obtained many valuable information, which has made great contributions to people's understanding of Venus.
The Soviet Union was the first to launch a probe into Venus. On January 24, 1961, an experimental launch was carried out, but the probe lost control and failed.Twenty days later, on February 12, the Soviet Union's first Venus probe, "Venus" 1, was launched into the sky.Weighing 643 kg, the detector is equipped with advanced equipment such as track measurement system, engine calibration device, first used telecommunication device and new high-temperature solar cell.After flying 100000 kilometers away from Venus, the communication between the probe and the ground was interrupted.
On November 12 and 15, 1965, the Soviet Union successfully launched the "Venus" 2 and 3 probes, each weighing 963 kg, equipped with a television camera system and a complete set of equipment for investigating Venus.When Venus 2 flew over 24000 kilometers away from Venus on February 27 of the next year, communication was interrupted;When Venus 3 approached Venus on March 1 of the next year, its telemetry failed, and it was impossible to determine whether its landing capsule reached the surface of Venus.
On June 12, 1967, Venus 4 was launched. The probe weighed 1106 kg. After 128 days of flight, it rendezvous with Venus and released the landing capsule.One and a half hours later, it detected the density, temperature and chemical composition of Venus' atmosphere, but the landing capsule was compressed by high pressure before it reached the surface of Venus.
On January 5 and 10, 1969, the Soviet Union launched the "Venus" 5 and 6 probes. They landed in Venus on May 16 and 17 of the same year, respectively. They measured the atmospheric data, but failed to send back the data on the surface of Venus.
Venus 7, launched on August 17, 1970, finally achieved a soft landing on Venus on December 15 of the same year, sending back the surface of Venus to the Earth for the first time.Venus 7 weighs 1180kg, of which the landing module weighs about 500kg.During its 23 minute descent, it investigated the internal conditions and surface structure of Venus' atmosphere.The data returned showed that the pressure of the landing module reached 90 atmospheres and the temperature reached 470 degrees Celsius.The atmosphere is mainly composed of carbon dioxide and a small amount of oxygen, nitrogen and other gases.Venus 7 became the first human envoy to visit Venus on the spot.Since then, the Soviet Union has launched nine more Venus probes.The landing capsule of Venus 8, which was launched on March 27, 1972, detected the soil on the surface of Venus on July 22 of the same year. The images sent back show that the surface of Venus is very bright.
On June 8 and 14, 1975, "Venus" 9 and 10 set off. Four months later, on October 22 and 25, they entered different orbits of Venus respectively. The weight of the landing module of both probes increased to 1560 kg.
Venus 11 and 12, launched on September 9 and 14, 1978, worked for 110 minutes after soft landing on the surface of Venus.These two probes are composed of a Venus lander and a Venus orbiter. When Venus - 11 and Venus - 12 are close to Venus, a lander will be separated from the planet. Before landing on the surface of Venus, the lander will continue to relay its photos to the Earth through Venus - 11 or - 12 flying to Venus.[2]
On October 30 and November 4, 1981, Venus 13 and 14, carrying automatic drilling and production equipment, collected rock samples on Venus.Venus 15 and 16, launched in 1983, sent back images of Venus.
In December 1984, the Soviet Union launched two "Vega" probes, and on June 11 and 15, 1985, it successively dropped detection devices on the surface of Venus, investigated the soil and clouds of Venus, and sent back valuable data to the ground.The "Venus" series of probes have carried out a total of 24 years of flight investigation.
U.S.A
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Mariner 2
The first successful probe in the Mariner series of NASA is the first successful interstellar probe in the world.As“Mariner 1 ”The weight of MARINER 2 backed up by the spacecraft is 202.80 kg. Its mission is to try to fly over Venus and send back the atmosphere, magnetic field, mass and other data of the planet.On December 14, 1962, "Sailor 2" passed through Venus at a distance of 34773 km from Venus, and continuously sent back the detected data before January 3, 1963. On the whole, the mission of this trip was extremely successful, and "Sailor 2" was still in solar orbit.
Sailor 5
OriginallyMariner 4 The original mission target of the backup probe is also Mars.Because Mariner 4 successfully completed the mission, Mariner 5's goal was changed to Venus.It reached the nearest place to Venus on October 17, 1967, when it was 4000 kilometers away from Venus.Due to the installation of a more advanced detector than Mariner 2, the data it sends back is richer and more detailed.
Pioneer Venus Probe 1 and 2
The Pioneer Venus 1 and 2 probes launched in May and August 1978 entered the orbit around Venus one after another, and the radar on the probe took images of the back of Venus.After entering the orbit around Venus, Pioneer Venus 2 released four conical Venus atmospheric detectors, which landed on the surface of Venus from four directions, and found that there were a large number ofcarbon dioxideandsulphuric acid, sulfur gas ejected 70 kilometers above the surface of Venus.
Magellan
Magellan detector
If the classic of the Jupiter probe is Galileo,Saturn probeThe classic of is "Cassini Huygens",Space telescopeThe classic of“Hubble”The classic of long journey is "traveler", and the classic of Venus probe is "Magellan".This monster, launched from the space shuttle in 1989, is the most successful Venus probe to date.Magellan detectorWeighing 3365kg, it is equipped with an advanced television camera radar system, which can map out the image of an object the size of a football field on Venus through thick clouds.After 462 days of space flight, it flew to Venus on August 10, 1990 and sent back measured data and photos to the Earth every 40 minutes.The Magellan probe obtained the first complete map of Venus for the first time, providing image data for studying the geology and geomorphology of Venus.
United States and Russia cooperate in surveying
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According to the British Daily Mail, currently, NASA and the Russian Space Research Center are planning to launch probes and landers to Venus in 2025-2026.[3]
Recently, scientists from NASA and the Russian Space Research Center will jointly discuss the Venus exploration plan. This space mission is named "Venera D". Scientists plan to launch RussiaSpace probeIt will take three years to reach the orbit of Venus, and the lander will operate for several hours in the harsh surface environment of Venus.This international joint space program will help reveal the ancient climate of Venus and analyze whether the planet is fertilelifeAt the end of January, NASA headquarters reported and evaluated the Venus exploration mission, and refined the mission objectives.[3]
Jim Green, director of the planetary science department of NASA, said: "Although Venus is the 'sister planet' of the Earth, we still need to make in-depth exploration, including: analyze whether Venus once owned oceans, whether it bred life, etc. Through understanding Venus and Mars, we will further improve our understanding ofterrestrial planetThe cognition of evolutionary history can provide insight into the past, current and future changes of the earth. "At the same time, the research team will study the feasibility of launching a solar powered airship to the top atmosphere of Venus. The airship enters the atmosphere of Venus and explores Venus for about three months.Venus is similar to the Earth in volume and composition, but it rotates slowly, in the opposite direction of the Earth's rotation, that is, from east to west.[3]
Venus's dense atmosphere can trap heat and form an overflowgreenhouse effect, eventually making it the hottest planet in the solar system, the surface temperature is high enough to melt lead.David Senske, co chairman of the US "Wenera-D" scientific definition group, said: "In the solar system, the Earth and Venus are very similar, and they have similar volume and composition. This space exploration plan aims to find partners to jointly study and analyze the mechanism of Venus climate change, through which inhibition may be foundGlobal greenhouse effectEffective measures. "[3]
European Space Agency
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Venus Express detector
Venus Express It is the first European mission to Venus, and the launch date is November 9, 2005.The transmitter is manufactured by Starsem, a joint European/Russian companySoyuz spacecraft。Launch mass 1270 kg, including 93 kgTrackerPayloadAnd 570 kg of fuel.Orbiter equipment includes: Venus surveillance camera, spacePlasmaAnd active atom analyzer, etc.The spacecraft was operated by the European Space Control Center in Darmstadt, Germany.
According to foreign media reports, scientists believe that a large number of lava flows covered the surface of Venus in a lava flow disaster 500 million years ago, but astronomers have not found conclusive evidence of the current volcanic activity of Venus.At present, the "Venus Express" detector has recently found signs of Venus volcanic eruption, which will help reveal how Venus formed.Eugene Shalygin of the Max Planck Institute of Solar System in Germany said: "We observed that the hot spots on the surface of Venus would suddenly become hot for many times and then cool down." Through radar image data, it can be found that these four hot spots are located in the geological fault zone, but this is the first time to detect that the temperature of the hot spots changes significantly day by day.This is the most convincing evidence for the discovery of Venus volcanic activity so far. These hot spots are close to the Ozamons and Matmans volcanoes along the Ganiki Chasma fault zone.[4]
Fault zoneIt is the result of surface structure fracture, often associated withCrustunderMagmaUpsurge is closely related.This process will cause hot materials to gush to the surface, which is likely to release lava flow through the fault zone.The researchers measured that the hot spot area of "Target A" is about 1 square kilometer, and the temperature is as high as 830 ℃, which is much higher than the global average temperature of Venus, 480 ℃.This latest research is consistent with other survey data of the Venus Express probe, suggesting that there is volcanic activity on the surface of the planet in the near future.In 2010, infrared observation images of several volcanoes on Venus showed that there were lava flow structures formed millions of years ago.A few years later, scientists reported that Venus's upper atmospheresulfur dioxideThere is a temporary peak, suggesting that there is volcanic activity on the planet.[4]
But this is the first time that scientists have found significant changes in the surface brightness of Venus within a few days. Hakan Svedhem, a scientist of the European Space Agency's "Venus Express" project"It seems that we can finally include Venus as one of the members of the solar system with volcanic activity. Our research shows that the volcanoes on the surface of Venus are still active, which provides important clues for us to study and analyze the different evolutionary histories of the Earth and Venus."[4]
Japan
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fromJapan Aerospace Research and Development AgencyThe developed "Akatsuki" Venus probe will try to enter the orbit of Venus again in December this year, which is the second time since December 2010 that the "Akatsuki" probe has the opportunity to enter the orbit of Venus.Five years ago, Dawn arrived near Venus, but it could not enter the orbit of Venus due to the failure of its main engine, so Dawn could only circle the sun and wait for the opportunity to enter the orbit of Venus.In December this year, Dawn is expected to miss Venus again. Because the main engine failure still exists, the probe can only use the side thruster to control the direction and wait for the opportunity to enter the orbit of Venus.[5]
Japan's first Venus probe
The Dawn probe is the first one developed by the Japanese space agencyExtraterrestrial objectsClimate spacecraft, designed to study the atmosphere of Venus.When arriving near Venus, Japanese scientists found that the main engine on the probe failed to complete thrust output, so Dawn could not enter the orbit of Venus.In the next five years, Dawn was unable to complete its scientific mission and had to wait for the opportunity in December this year.Japanese scientists believe that if it succeeds this time, Dawn will enter a high elliptical orbit, and it will take eight to nine days to orbit Venus for one week.[5]
In the mission update in February this year, officials of the Japan Aerospace Exploration Agency mentioned that the "Dawn" entered the orbit at a height 10 times the radius of Venus. The "Dawn" can detect the cloud layer and atmospheric composition of Venus and study its surface condition.When the orbital height of Dawn is less than 10 times the radius of Venus, you can closely study the convective activities and small fluctuations on the cloud layer, and master the mystery of Venus' thick cloud layer.Dawn can also detect the volcanoes on the surface of Venus. At present, the antenna on the probe is also faulty, and the contact with the earth is intermittent."Dawn" cost 300 million dollars, and Japanese scientists tried to use the probe to conduct a comprehensive study of Venus.In this launch mission, IKAROSSolar sail spacecraftThe detector has used solar light pressure to fly, and solar sails are expected to become a new power source for future spacecraft.[5]
On December 9, 2015 Beijing time, it was reported that after five years of delay and suffering, Japan's Akatsuki Venus probe finally successfully entered the orbit of Venus.At 8:51 a.m. on December 7 (Beijing time: 7:51 a.m.), Japanese Standard Time, four small engines of the Venus probe "Xiao" began to ignite and started continuously for about 20 minutes.The weak propulsive force provided by this action successfully reduced the flight speed of the probe and made it captured by the gravitational field of Venus.[6]
