Voyager 2[19]）AtKennedy Space CenterSuccessful launch, yesNASATwo ships developed to fly outside the solar systemSpace probeThe second ship of.
Initially, this probe was used as Sailor 12 in the Sailor Plan, and it became a part of the Voyager PlanTraveler 1number（seamanNo. 11)Sisters ofprobeDevice.Both aircraft use plutoniumBattery(Nuclear power battery)Energy supply.
Voyager 2 approached Saturn in a slightly different trajectory, by approachingTitanTitanA gravitational slingshot produced by the force of gravity.After detecting Saturn, it continued to flyUranusandNeptune。
Voyager 2 was the first flying probe to visit the two planets at such a distance.Voyager 2 passed Uranus in 1986 and Neptune in 1989. Many instruments on the probe have been turned off, but it continues to explore the environment of the solar system.
On December 10, 2018, the Voyager 2 spacecraft flew away from the solar wind layer, becoming the second spacecraft to enter interstellar space.[1]
Voyager was originally planned to belong to the United StatesSailor PlanThe design of the Sailor 11 spaceship made use of the new technology of gravity acceleration at that time.Fortunately, this mission happened to encounter the geometric arrangement of planets once in 176 years.Spaceships need a small amount of fuel for channel correction, and the rest of the time can be accelerated with the help of the gravity of each planet. A spaceship can visit four gas planets in the solar system:Jupiter、Saturn、UranusandNeptune。The two sister ships Voyager 1 and Voyager 2 were designed for this opportunity, and their launch times were calculated to make full use of this opportunity.Thanks to this opportunity, it will take 12 years for two space ships to visit four planets, instead of the usual 30 years.[14]
Development process
Voyager 2 probe launched by Hercules 3E rocket
Voyager 2 was launched on August 20, 1977NASAUnmanned spacecraft.It and its sister shipVoyager 1Basically, the design is the same.The difference is that Voyager 2 follows a slower flight path, enabling it to maintainEcliptic(i.esolar systemIn 1981, it accelerated to Uranus and Neptune through the gravity of Saturn.Because of this, it is not as close as its sister Voyager 1titan。But it became the first spaceship to visit Uranus and Neptune, and completed the geometric arrangement of the planets once in 176 years to visit fourgas giant Opportunities.
Voyager 2 is believed to have been launched from EarthspacecraftThe most productive spaceship in China.Because NASAGalileoandCassini HuygensThe plan of the No. 1 spacecraft has been tightened. It can still visit four gas giant planets (Saturn, Jupiter, Uranus, Neptune) and their satellites with powerful cameras and a large number of scientific instruments.
If there is no unexpected failure, humans will be able to keep in touch with them until 2030.Both detectors also have a large amount of hydrazine fuel.The Voyager 1 propellant can be used until 2040, and the Voyager 2 propellant can be used until 2034.The limiting factor is RTG（radio isotopeThermoelectric generator).By 2000, the power of UVS (ultraviolet spectrometer) instruments will be exhausted.By 2010, the remaining power will make it impossible for all field and particle instruments to work at the same time.At this time, an energy sharing scheme will be implemented to make some of the field and particle instruments work in turn with others.The aircraft can work continuously in this state for about 10 years.In the end, the energy may be too little to maintain the normal operation of the aircraft.
Like Voyager-1, Voyager-2 also carries a number of so-called“Earth Business Card”--They include gold-plated copper pieces with various geometric patterns, and turntables recording various sounds on the earth, in order to let possible extraterrestrial intelligent creatures know that life also exists on the earth.
According to astronomers' calculations, if Voyager-2 can fly down smoothly all the time, theoretically, it will fly to Barnard star 6 light years away from Earth in 8571 AD[8]By 20319, it will fly 3.5 light years away from Centaurus, and by 296036, it will reachSiriusNearest, about 4.3 light years.[3]
system composition
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overall design
The overall structure of Voyager 2 detector is a flat decagonal prism with a spherical fuel tank in the center and electronic equipment around.The detector head is equipped with a large straw hat shaped device - a 3.7m diameterParabolic antennaI.edirectional antennaThe two strip antennas at the bottom are actuallyWhip antenna。The two arms stretched to the left and right, one is long and the other is shortmagnetometerSupport rod, the short one is the infrared interferometer bracket, exceptInfrared spectrometerBesides, there arecosmic rayDetectorPlasmaDetector, wide-angle camera, narrow angle cameraUltraviolet spectrometer。The side of Voyager 2 is also hung with a generator for replenishing energyradio isotopeTwo thermoelectric generatorsNuclear battery, also called plutonium battery.16 small units are installed on the upper side of the fuel tankLiquid rocket engineFor the detector to change the flight direction and adjust the attitude.[15][19]
Voyager 2
Energy installations
The nuclear battery (code name: RTG) of Voyager 2 provides power for spacecraft systems and instruments by using three radioisotope thermoelectric generators.The RTG of the nuclear battery is assembled in series on a deployable boom, which is hinged on the leg arrangement of the pillar connected to the basic structure.Each nuclear battery unit is installed inberylliumIn the shell, the diameter is 406 mm, the length is 508 mm, and the weight is 39 kg.Nuclear battery RTG uses plutonium-238 as the radioactive source, which will release heat when plutonium decays.Bimetal thermonuclear batteries are used to convert heat into power for spacecraft.With the consumption of radioactive materials, the total energy output of nuclear battery RTG will slowly decline over time.Therefore, although the initial output of the nuclear battery on Voyager 2 was about 470 W (30 V DC) at launch, its output power had dropped to about 335 W by the beginning of 1997 (about 19.5 years after launch).With the continuous decline of power, the power load of the load device on the spacecraft must also be reduced.It is expected that limited instrument operation will be available at least until 2025.[16-17]
Voyager 2's radio communication system can be used in the solar system.The communication system includes a parabolic high gain antenna with a diameter of 3.7 meters, which is used to communicate with three deep space stations on the earth.Aircraft usually use 2.3GHz or 8.4GHz frequency to transmit data to the earth, and use 2.1GHz frequency from the earth to send signals to Voyager 2.When Traveler 1 cannot communicate directly with the earth, its digital tape recorder (DTR) can record about 64KB of data for transmission at other times.
Voyager 2 communication is provided by high gain antenna and low gain antenna.The high gain antenna supports both X-band and S-band downlink telemetry.Voyager was the first spacecraft to use X-band as the main telemetry link frequency.The data can be stored for later transmission to the Earth using on-board digital tape recorders.[16-17]
Flight control device
The space flight of Voyager 2 is far from the earth, and its command time lags behind, so it is designed to operate in a highly autonomous manner.In order to do this and execute the complex procedures of spacecraft flight and instrument operation, the probe uses three interconnected on-board computers.The computer command subsystem (CCS) is responsible for storing the instructions of the other two computers and issuing instructions at the set time.The flight attitude and node control subsystem (AACS) of the probe is responsible for controlling the attitude of the spacecraft and the movement of the scanning platform.Flight data subsystem (FDS) control instruments, including configuration (status) or telemetry rate changes.All three computers have redundant components to ensure continuous operation.AACS includes redundant star trackers and solar sensors.[16-17]
Composition diagram of Voyager 2 detector
Carrier rocket
The carrier rocket for launching Voyager 2 probe is the Hercules 3E carrier rocket (Centaur) developed by the United States.
Hercules 3E rocket is AmericanHercules Series Launch VehicleThe Hercules 3 rocket is developed by the US Department of Defense. It has five models, A, B, C, D and E, and can launch various orbital satellites. The representative is the "Hercules 3C" rocket.The rocket is developed from "Hercules 3A" and is mainly used to launch military synchronous orbit satellites.The maximum length of the rocket is 50.6 meters and the maximum diameter is 9.7 meters.[18]
From May 1972 to flying close to Neptune, 865 million dollars
Flight information
Carrier rocket
Hercules 3E (nickname: Centaurus)
Date of launch
September 5, 1977
Launch site
Cape Canaveral, Florida, USA[16]
Mission load
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Voyager 2 is known as the most valuable detector because it visited many planets and their moons: on July 9, 1979, it was the closest to Jupiter, found several more rings around Jupiter, and took pictures of Jupiter, showing its volcanic activity.It was closest to Saturn on August 25, 1981.Later, using the gravity of Saturn, like "slingshot", it was the closest to Uranus on January 24, 1986, and discovered 10 previously unknown natural satellites.Voyager 2 was the closest to Neptune on August 25, 1989.Both Voyager probes carry gold plated copper records to communicate with the spacecraft when they are captured by intelligent creatures in outer space.It records the singing of birds, the sound of wind, the sound of human conversation, etc.[2]
Detecting instrument
Edward C. Stone, Jet Propulsion Room, NASA
Voyager 2 carries exploration instruments, which together provide valuable information about Saturn and Jupiter, and will continue to cooperate to realize the interplanetary mission of Voyager 2:
High field and low field magnetometers (MAG)
MAG aims to measure the changes in the solar magnetic field to determine whether each exoplanet has a magnetic field, and how the satellites and rings of the exoplanet interact with these magnetic fields.
Low energy charged particle (LECP)
LECP measures the velocity and direction of cosmic radiation in the Milky Way, especially at low energies.It has the widest energy range among three groups of particle sensors, and analyzes interplanetary energetic particles.
Plasma subsystem (PLS)
The purpose of PLS is to study the interaction of the solar wind with Jupiter and Saturn, and to explore the regions where the solar wind slows down and becomes denser.As Voyager 2 approaches the zenith boundary, the instrument will detect interstellar media for the first time.
Cosmic Ray Subsystem (CRS)
CRS looks for high-energy particles from other stars found in strong radiation fields around some planets.
Planetary radio astronomy (PRA)
PRA is a complex radio receiver used to listen to radio signals generated by the sun, planets and their magnetosphere.It helps to describe planetary radio emissions and their relationship with planetary satellites, and to detect lightning in the planet's atmosphere.
Plasma wave subsystem (PWS)
Like PRA, PWS is a radio receiver and amplifier.It monitors the frequency that the human ear can hear and the signal slightly higher than the audible frequency.It helps to determine the characteristics of the plasma (ionized gas) signal related to the planetary ring, and will continue to determine the properties of the plasma.
Ultraviolet spectrometer subsystem (UVS)
UVS looks for ultraviolet rays of certain colors emitted by certain elements and compounds.Ultraviolet radiation helps to determine the ultraviolet characteristics of planetary rings and look for traces of any ring "atmosphere".The scientific data collected with the detection instrument was sent back to the earth in real time at the speed of 160bps.[23]
Carry items
The Voyager 2 probe launched by the United States carried a special record.This is a gift for aliens. Use it to find the tracks of aliens.
This copper record has a diameter of 30.5 cm and is coated with a gold film.The 90 minute "Voice of the Earth" was recorded on one side of the record, including greetings from 60 different national languages, 35 natural sounds and 27 ancient and modern world famous songs.On the other side, 115 photos reflecting human civilization on the earth were recorded. In addition, congratulatory messages from US President Carter and UN Secretary General Waldheim were also recorded.
Among the greetings are Chinese Mandarin, Cantonese, Minnan and Wu. A lady in Guangdong sent a warm greeting to aliens in Cantonese: "How are you? Wish you all peace, health and happiness." A woman in Xiamen said: "Hello, space friends! Have you eaten yet? Please come here when you are free." Wu said: "Hello, everyone.”The last man said in Mandarin: "All right, everyone. We miss you very much. Please come here when you are free."Guqin performanceThe music of "Flowing Water" in "High Mountains and Flowing Water".In the photos of human beings on earth, there are the majesty of the Badaling Great Wall and the style of the Chinese family banquet.This "Voice of the Earth" record can be preserved in space for 1 billion years.[2][4]
Voyager 2 was originally planned to belong to the Sailor 12 spacecraft in the Sailor Program.It was signed on August 20, 1977FloridaCape Canaveral, carried in a Titan 3 ECentaurThe rocket was launched into the sky.Due to the negligence of the ground staff, they forgot to send an important startup code to Voyager 2, which caused the spacecraft to shut down theHigh gain antenna。Fortunately, the ground staff finally succeeded in contacting the low gain antenna on the ship and restarting the high gain antenna on the ship.[19]
On Jupiter
Voyager 2 came closest to Jupiter on July 9, 1979, passing 570000 kilometers (350000 miles) from the top of Jupiter's cloud.This visit found several more rings around Jupiter and photographed someIoA photo showing its volcanic activity.
Jupiter is the largest planet in the solar system, mainly composed of hydrogen and helium, and a small amount of methane, ammonia, water vapor and other compounds.And the central government issilicateA core of rock and iron.The colorful clouds on Jupiter show the unpredictable weather in Jupiter's atmosphere.Jupiter also has 63 natural satellites, the largest number for the time being.Jupiter's revolution period is 11.8 years,rotationThe cycle is 9 hours and 55 minutes.
Although astronomers have studied the planet through telescopes for centuries, the discovery of Voyager 2 still surprised scientists.For example, the famousGreat Red Spot StormIt is found that it is a complex storm system rotating counterclockwise, and some small storms and eddies are also found.
The discovery of an active volcano on Io shocked scientists in another way.This is because for the first time, scientists have found active volcanic activity in other stars in the solar system.Voyager 2 observed the eruption of nine volcanoes on Io this time, which also confirmed other volcanic eruptions that occurred during the visit of two Voyager spacecraft.Smoke from volcanic eruptions is ejected 300 kilometers (190 miles) above the surface of Io.The speed of the material ejected from the volcanic eruption is as high as one kilometer per second.The energy of Io's volcanic eruptions may come from the tidal forces between Io and Jupiter, Europa and Ganymede.Because these three satellites are locked inLaplaceOn the resonance track, that is, Europa rotates twice and Europa rotates once;When Europa spins twice, Ganymede spins again.Although Io always faces Jupiter on one side, Europa and Ganymede make it slightly wobble.This rocking force is so powerful that Io bends up to 100 meters (330 feet), compared with only 1 meter (3 feet) on Earth.The volcanic activity on Io also affected the entire Jupiter system, and its influence spread throughout Jupiter's magnetic circle.Sulfuric acid, oxygen and sodium apparently spewed out with the volcanoes on Io, and the surface of the moon was also splashed by high-energy particles.These splashes even reached the boundary of Io's magnetic circle, millions of miles away from its surface.
As for Europa, it can be seen from the low resolution photos of Voyager 1 that there are traces of crisscross textures on its surface.At first, scientists believed that the arts and sciences originated from cracks formed by crustal movement or tectonic activity.However, the high resolution photos provided by Voyager 2 later annoyed the scientists because those features lacked the topographical outline.As one of the scientists described, "Those features are like a thick ink pen.".It is possible that Europa is also affected by the tidal force, which causes friction and heat of 10% or less of Ganymede.It is generally believed that Europa has a thin ice crust (less than 30 kilometers or 18 miles), which hides an ocean about 50 kilometers (30 miles) deep.
GanymedeIt is the largest natural satellite in the solar system, with a diameter of 5276 kilometers (3280 miles).This trip confirmed that Ganymede has two distinct landforms: many pits and many deep trenches.Scientists believe that Ganymede's ice crust is affected by the tension of crustal tectonic activities.
GanymedeThe remnants of ancient meteorite craters in the crust show many traces of meteorite impact.The largest crater was apparently filled up over time due to the movement of the ice layer on the crust, because there were almost no obvious topographic features left on the basin full of impact marks.This is the reason why the impact trace was confirmed because it left a lighter color and fadedCrater。
Jupiter was found to have a faint, powdery ring.The outer edge of the ring is 129000 km (80000 miles) from the center of Jupiter, while the inner edge is 30000 km (18000 miles) from the center of Jupiter.At the same time, this trip also found two small satellites, Ganymede 15 and Ganymede 16, which happened to be in theJupiter RingPeripheral operation of.The third newly discovered satellite, Ganymede XIV, is orbiting between Ganymede and Io.
Jupiter's rings and moons appear in its dense magnetic field, which is full of electron and ion radiation belts.These particles and magnetic fields form Jupiter's magnetic circle, extending 3 to 7 million kilometers toward the sun, and extending to reach at least Saturn's orbit, that is, 750 million kilometers (460 million miles) away.Since the magnetic circle will follow Jupiter's rotation, it will sweep through Io and strip off a metric ton of material every second.These substances will form an annular ion cloud that can only be seen under ultraviolet light. This ion cloud will move outward, making Jupiter's magnetic circle twice larger than normal.Some energetic sulfuric acid and oxygen ions will fall into this magnetic field and then enter Jupiter's atmosphere, forming auroras.
When Io crosses Jupiter's magnetic field, it acts like a dynamo, developing a voltage of 400000 volts across its diameter and simultaneously producing a current of about 3 million amperes, which flows from the magnetic field to Jupiter's ionosphere.Voyager 2 finally visited Jupiter and left several days later, and took many pictures of Jupiter.[19]
Explore Saturn
Saturn and its moons
Voyager 2 was closest to Saturn on August 25, 1981.When the spacecraft is behind Saturn (relative to the Earth), it uses radar to detect the upper atmosphere of Saturn, and measures the temperature and density.Voyager 2 found that the temperature at the upper level (when the air pressure is equal to 7 hPa) was 70K (- 203 ° C), while at the lower level (when the air pressure is equal to 120 hPa), 143K (- 130 ° C) was measured.The Arctic will be 10K colder, but there will still be seasonal changes.
After passing Saturn, the shooting platform on the ship was a bit stuck, which made the mission to Uranus and Neptune variable.Fortunately, the staff on the ground finally solved the problem because the lubricating oil was temporarily exhausted due to excessive use.In the end, the spaceship still received the order to continue to move forward and go to Uranus.[19]
Explore Uranus
Voyager 2 was the closest to Uranus on January 24, 1986, and then discovered 10 previously unknown natural satellites.In addition, the spacecraft also explored the unique atmosphere of Uranus due to its rotation axis tilting by 97.77 °, and observed itsPlanetary ringSystem.In this first pass, the closest approach to Uranus is only 81500 kilometers (50600 miles) from the top of Uranus's clouds.
Uranus is the third largest planet in the solar system. It orbits the sun at a distance of about 2.8 billion kilometers (1.7 billion miles) from the sun.Its revolution period is 84 years, and its rotation period is 17 hours and 14 minutes.Uranus's rotation is unique because it actually dumps in its orbit and rolls. It is generally believed that this unusual position is due to the reason that it collided with a planet sized star in the early formation of the solar system.Because of its strange positioning, its poles will accept 42 years of day or night, so scientists do not know what will be found on Uranus.
Uranus photos
Voyager 2 found that one of the effects of Uranus's tilt position on its 60 degree magnetic field was that its magnetic tail was twisted into a spiral shape due to Uranus's rotation, and appeared behind Uranus.However, people did not know that Uranus had a magnetic field before the tourists visited.
Uranus's radiation belt was found as dense as Saturn's.The intensity of radiation in the radiation belt will make the light dim any methane trapped on the satellite or the ice surface in the ring rapidly (within 100000 years).This explains why most of Uranus's moons and rings are gray.
Some high-level fog is detected at the pole of direct sunlight, and it is found that these fog help spread a lot of ultraviolet light, which is called "sunrise".The average temperature is 60K (- 350 ° F).Surprisingly, the temperature at the cloud top of the whole planet is almost the same, even at the illuminated pole and the dark pole.
Among the five largest natural satellites, Rhea, whose orbit is closest to Uranus, shows that it is one of the strangest stars in the solar system.When Voyager 2 flew by, from the detailed photos taken back, it was seen that there were some valleys as deep as 20 kilometers (12 miles), uplifted faults and the surface mixed with old and new years.Some theories suggest that Diospyros may be a recombination of some materials that were broken after violent impact in the early period.
The spacecraft also observed nine known rings, showing that Uranus's rings are quite different from those of Jupiter and Saturn.The whole star ring system is relatively new, not formed together with Uranus.The constituent particles in the ring may be a satellite fragment torn up by high-speed impact or tidal force.[19]
Detecting Neptune
Voyager 2 was closest to Neptune on August 25, 1989.Since this is the last planet that Voyager 2 can visit, it decided to adjust its channel to be closer to Triton, ignoring its flight path, just likeVoyager 1After completing the visit to Saturn, regardless of the flight path closer to Titan to study the same.
The spacecraft found Neptune'sLarge scotoma, later onHubble Space TelescopeIt disappeared when it was observed again in 1994.At first it was thought to be a large cloud, but later it was thought to be a hole in the cloud.
Visited by Voyager 2NeptuneLater, Pluto was the only planet that was still not visited by any spaceship flying from Earth.But after the International Astronomical Society redefined the planet, Pluto was downgraded to adwarf planet。Therefore, the omission of Voyager 2 in 1989 made all planets in the solar system visited by artificial spacecraft at least once.(Pluto has beenNew Horizons Visited at 19:49 on July 14, 2015 Beijing time.)
Voyager 2 also flew to Triton for investigation, and found that Triton was indeed the only large satellite in the solar system that was retrograde along the direction of the rotation of the planet, and it was also the coldest celestial body in the solar system.It is brighter, colder and smaller than originally thought. Its surface temperature is - 240 ℃. Some areas are covered with water ice and snow, and it often snows.There are three seats on itIce volcano, once ejected frozen methane or nitrogen ice particles, sometimes up to 32 km high.There may be liquid nitrogen oceans and ice lakes on Triton, and there are faults, mountains, canyons and glaciers everywhere, which indicates that similar earthquakes may have occurred on Triton.Triton has a thin atmosphere composed of nitrogen, and its polar cap is frozen with nitrogen to form a dazzling white world.[19]
Fly away from the solar system
Since Voyager 2's mission to visit the planets has ended, Voyager 1 has been described by NASA as an interstellar exploration mission to search forHeliosphereWhat is the outer solar system like.It is generally believed that Voyager 1 flew over in December 2004Terminal seismic wave area, who is nowheliosheath inDifferent from No. 1, it is generally believed that No. 2 still does not fly over the terminal seismic wave.Each tourist spaceship carries a piece ofVoyager Golden Record In case the spaceship is captured by intelligent creatures in outer space.The record contains images of the earth and various creatures, some scientific information and a serial music "The Sound of the Earth".The song includes such music as whales, babies crying, waves beating and different kinds of music.
On September 5, 2006, Voyager 2 was about 80.5 astronomical units (about 12 meters) away from the sunEcliptic discrete objectsAnd is taking 3.3Astronomical unitSpeed forward.At this distance, the sun andPlutoThe distance between thesedna The perihelion of is far, but has not been exceededErisThe orbit of is farthest.[17][19]
Voyager 2 will continue to transmit signals until the 2020s.
Space Flight Path Diagram of Voyager 2 Probe
Voyager 2 loss of function schedule (estimated)
particular year
Function of stopping operation due to limited power
one thousand nine hundred and ninety-eight
Stop scanning platform and ultraviolet observation
two thousand and seven
Stop tape recorder operation (no longer required due to high waveform receiver failure on Plasma Wave Subsystem (PWS) on June 30, 2002)
two thousand and eight
Stop Planetary Radio Astronomy Experiment (PRA)
About 2015
Stop gyroscope operation
About 2020
Start sharing power between instruments
About 2025 or later
Cannot start any single instrument[17]
Enter interstellar space
On December 10, 2018, NASA announced that Voyager 2 had left the solar wind layer and become the second probe to enter interstellar space.[1]
Selected Space Photography of Voyager 2
Follow up flight
On August 30, 2007, after 30 years of long journey, Voyager 2 spacecraft directly observed the termination shock at 85 astronomical units away from the earth (one astronomical unit is the average distance between the earth and the sun, that is, 150 million kilometers), which is the first time in human history that the information returned to the edge of the solar system.
Due to the change of the dynamic pressure of the solar wind and the influence of fluctuations, the termination shock wave is not stationary, but moves back and forth along the radial direction, resulting in multiple crossings of the Voyager 2 spacecraft.Through the detailed analysis of the detection data, new important findings are obtained:
(1) In general, the shock wave will change the supersonic (Mach number greater than 1) fluid to subsonic (Mach number less than 1), while the downstream of the terminating shock wave is stillSupersonic flow；
(2) DownstreamPlasmaThe temperature of is more than 10 times lower than the theoretical expected value.The main reason for the inconsistency with the shock wave characteristics familiar to humans is thatInterstellar mediumThere are a large number of neutral components in.These neutral components (mainly neutral hydrogen atoms) and ionized solar wind protons generate new ions (Pickup Ions) through charge exchange.Most of the energy generated by the reduction of the dynamic energy of the solar wind is supplied to the newborn particles, and only a small part of the energy is used to heat the solar wind plasma, which causes the temperature of the solar wind plasma downstream of the termination shock wave to be lower than the expected value, thus reducing the sound speed, resulting in the Mach number downstream of the termination shock wave still greater than 1.As Voyager 2 continues to explore in the heliospheric sheath, more and more natural mysteries of the edge of the solar system will be revealed by mankind.
Voyager 2
As of October 2009, Voyager 2 has made an inclination of - 54.55 ° and a right ascension of 19.737 hrs, pointing to the constellation of telescopes.Voyager 2 is at a distance of 90.557 astronomical units from the sun, leaving the solar system at a speed of 3.268 astronomical units (about 15.493 kilometers per second) every year.
From the end of April to the beginning of May 2010, Voyager 2 moved to the edge of the solar system.On April 22, Voyager 2 sent some very strange signals to the earth. After 13 hours, the signals were successfully received by NASA's deep space antenna.But unfortunately,NASAOur scientists can't decipher it.The famous German UFO expert Hausdorf boldly asserted that Voyager 2 might have been hijacked by aliens.Hausdorff said: "It seems that the spaceship was hijacked and the program was rewritten, so humans cannot decipher it." NASA did not respond to Hausdorff's opinion, but scientists and engineers believe thatstorage system There may be a small fault.The staff are actively repairing.[5]
On November 29, 2011 (Beijing time), it was reported by Time magazine that after 34 years of flight, the American Voyager 2 probe had switched to the standby attitude control thruster on November 4 as instructed by the ground engineer to save energy and ensure the continuation of future missions.
As of 2011“Voyager 1It is about 11 billion miles (about 18 billion kilometers) away from the earth, and Voyager 2 is 9 billion miles (about 14 billion kilometers) away from the earth.
On December 10, 2018, the Voyager 2 spacecraft flew away from the solar wind layer, becoming the second spacecraft to enter interstellar space.
On November 9, 2020, The Australian reported that Voyager 2 was 18.7 billion kilometers away from the earth. Even if the communication signal was transmitted at the speed of light, it would take more than 17 hours to reach the earth after it was sent from Voyager 2.It can only rely onNASA(NASA) No. 43 deep space exploration station in Australia contacted the ground control station.From March 2020, 43 deep space exploration station will be fully upgraded, and Voyager 2 will not receive any instructions from the Earth during this period.This situation will last until October 30, 2020. After the preliminary upgrade of the 43 deep space exploration station, NASA sent a command to Voyager 2, "After 34 hours and 48 minutes of waiting, people got a sentence‘Hello’Feedback from.The test communication with Voyager 2 undoubtedly shows that everything is on track. "One of the farthest human probes, Voyager 2, which has reached the edge of the solar system, finally regained contact with the ground control station after losing contact for 8 months[6]。
On July 21, 2023, due to the wrong command issued by the ground controller, the antenna direction of Voyager 2 pointing to the earth deviated by 2 degrees from its original position.The probe is about 12.4 billion miles (19.9 billion kilometers) away from the Earth and is constantly moving deep into interstellar space.[11]This "small mistake" resulted in that Voyager 2 could not receive instructions from the Earth and could not send data back to the Earth.[21]On July 31, 2023, the National Aeronautics and Space Administration of the United States announced that it was trying to re-establish communication with the Voyager 2 probe using the giant dish antenna located in Canberra, Australia.[12]
On July 29, 2023, NASA released a dynamic update, saying that after the routine command sequence was executed, the antenna angle of Voyager 2 shifted by 2 degrees, which made it impossible to send data back to the Earth and interrupt communication with the ground.Voyager 2 finally began to send back scientific and telemetry data on August 4, indicating that it was operating normally and remained in the expected orbit.Voyager 2 is about 20 billion kilometers away from the earth, and its signal transmission to the earth takes more than 18 hours.
On August 4, 2023 local time, the National Aeronautics and Space Administration (NASA) announced the reestablishment of communication links with Voyager 2.[13]
On October 24, 2023, after 46 years of space flight, Voyager 2 is about 12 billion miles away from the Earth. NASA recently completed the first step of the "remote OTA update", which took 18 hours to complete the transmission of the "update package". If the test is successful, the "brush" program will be officially launched on October 28.[24]
Exploration achievements
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Flight record
Voyager 2
In the late 1970s, the United StatesNASATaking advantage of a rare planetary alignment opportunity once in hundreds of years, "two arrows and four eagles"“Voyager 1”Voyager 2, two outer planet probes.Voyager 1 completed most of its missions after flying over Jupiter and Saturn.Voyager 2, on the other hand, uses Saturn's gravity to change course and accelerate to Uranus, then to Neptune.For this purpose, thePasadenaNASA Jet Propulsion LaboratoryScientists have overcome many difficulties.It can be said that through remote control technology, scientists have "reassembled" a detector, adjusted most of the airborne equipment, including cameras, power systems and control computers, as well as communication devices, and launched theradio telescopeSending and receiving signals is a miracle in itself.[22]
Arrive at Uranus
Uranus
In January 1986, Voyager 2 flew to Uranus, and the data collected by the probe within 24 hours of the rendezvous were several times the data about Uranus that humans had obtained since the discovery of Uranus.Before that, mankind only knew that it was the seventh planet in the solar system, 2.9 billion kilometers away from the sun, 48000 kilometers in diameter, mainly composed of gas,Autorotation shaftDumped on the orbital plane, and there are 6 satellites.[22]
Discover satellites
Jupiter
Several rings around Uranus were discovered in 1977.In 2013, we discovered 10 new satellites, new rings and many other things that surprised us.First, the traveler's close observation of Uranus shows that Uranus is light blue, the same as the ground observation, which is very different from Jupiter and Saturn, but it is slightly red in its south pole, which is due to the atmosphericPhotochemical smogCaused by the effect.[22]
Uranus climate
In addition, it was found that the temperature of Uranus in the atmosphere is approximately the same, which is 208 ℃ below zero, and there is a mysterious cold circle at the latitude of 30 °, which puzzled scientists. They thought that the equator of Uranus should be 8 ℃ colder than the polar region.Because the temperature gradient that determines its meteorological process should be opposite to the "upright" planet.After electronic processing of the photos of Uranus's atmosphere, scientists found four clouds and investigated their flow velocity. Cloud tracking shows that all the winds on Uranus flow along the direction of rotation of the planet, with a wind speed of 161 km/h, which obviously violates a basic law in the atmosphere - the hot wind equation.
When the polar region of the planet is colder than the equator, the forward wind connected with the rotation direction of the planet accelerates with the increase of height.On Uranus, the polar region should be hotter than the equator, and the wind should be in the opposite direction, that is, the velocity of the wind should be lower than the rotation speed of the planet. This did not happen, and the temperature on Uranus was almost the same everywhere, so scientists had to reconstruct the atmospheric model of Uranus.The magnetic field observation of Uranus shows that the orientation of the magnetic axis has a great angle with its rotation, about 60 ℃, which is different from the planets that have been detected by humans in the solar system.Scientists suspect that the "strange" orientation of Uranus's magnetic axis may be caused by the interaction between Uranus's satellite and the magnetosphere.The magnetic field is very important, because if you want to understand the situation of the non gas part of Uranus hidden under the cloud of Uranus, the magnetic field is the only available information.Scientists measured the rotation period of Uranus, which is about 17.3 hours.[22]
Uranus geology
Voyager 2 pictures of Neptune
In addition, yesUranus satelliteMany important data have also been obtained from the detection of.The initial signals clearly showed many craters.From Triton inward, the closer the satellite is to Uranus, the stronger the geological activity will be;There is a long groove on Triton;On Triton, there are many light colored ribbon areas that seem to have just frosted;On the other hand, there are peculiar bright features on Diospyros, whose shape is similar to that of volcanoes.Only whenEnceladusThere is no sign of geological activity on the surface, and it has always remained dark and dull.Later, in the satellite puzzle sent back, scientists were able to study the satellites of Uranus more carefully.It is like the essence of popular songs, rather than an album. It focuses on almost all the geological features in the solar system.The long canyon is like the big one on the surface of Marscanyon, rows of grooves are similar to the surface of Ganymede, and the sunken rocks are similar toMercuryPressure fault, but the three most prominent features have never been seen before. There are a series of dark lines on the edge of the satellite, which looks like a pile of pancakes from the side. On the right side of the pressure fault, there is a mountain structure, which is surrounded by narrow, long and winding concentric cracks.Further to the right, on the edge of the sunshine side close to the satellite, there are a series of parallel grooves, turning vertically at one end, like a rectangular racetrack.Along one side of the racetrack, there is a deep valley, revealing a row of cliffs as high as several kilometers.In fact, Voyager 2 has raised more questions about Titan than it has revealed.ofUranus ringWe have also achieved great results in our exploration.
Uranus has a monochromatic appearance. Strangely, its magnetic field axis has a great deviation from its original axis of rotation, which makes its magnetosphere very strange.The Ice Channel was found on Triton,Tianwei FiveIt is a piece of strange terrain.Ten satellites and more than one halo were found.
Compared with Uranus, Neptune has a very active climate, and its clouds have various shapes.The halo arcs on a halo become sequins.In addition, six other satellites and two rings were found.NeptuneMagnetic field axisAlso very inclined.Triton The appearance is like a magnifying glass with corners, which looks like many fountains.[22]
scientific analysis
In the autumn of 1989, the Voyager 2 spacecraft passed Neptune 12 years after its voyage and was heading far away.It carries a metal plate, which tells the story of the earth and contains various places of interest and sounds on the planet.This made some people afraid. They thought that people were inadvertently leaking their positions to aliens from other worlds, who might conquer people.Those who have this idea do not understand the size of the universe, nor the probability that Voyager 2 may be discovered by anyone.Voyager 2 has spent 12 years from Earth to Neptune. What kind of world will it reach.Voyager 2 drifted under the gradually weakening gravitational field intensity of the sun (when it was far away from the sun) and the very small (almost zero) gravitational field of various stars.Considering these gravitational effects, people can know exactly where Voyager 2 is going.
Voyager 2
People know all the nearby stars, and Voyager 2 will not be able to collide with any of them.Of course, there may be unknown dark objects in space, and Voyager 2 may also collide with a wandering planet or asteroid, but the probability is too small, even if it is considered useless.The sun will send out "solar wind", that is, jet in all directionsCharged particle flow。When away from the sun, the jet becomes thinner and thinner until it disappears into interstellar space.In 2012, Voyager 2 will go beyond the reach of the solar wind.By 8571 (almost 6558 years from 2013), Voyager 2 will be 0.42 light years away from the sun, or about 2.5 trillion miles.However, even the nearest star is ten times the distance.By that time, Voyager 2 will be at a distance of 5.9 light-years (35 trillion miles) from EarthBarnard starClosest.Voyager 2 will be only 4.03 light years (24 trillion miles) away.After passing Barnard, it will continue to move forward.By 20319, Voyager 2 will be 1 light year (5.9 trillion miles) away from the sun, and at the same time, it will be the closest to the nearest star, Nearby Centaurus.Bilin is 4.3 light-years (25 trillion miles) away from people, but of course, Voyager 2 will not go in its direction.It is moving on one side, and its closest distance from the neighboring star is 3.21 light years (19 trillion miles).Only 310 years later, Voyager 2 will be adjacent to Centaurus a, which is a bit farther than Centaurus and the adjacent star.The distance from that closest point will be 3.47 light years (20 trillion miles).During this whole period, it must be understood that Voyager 2 is still close enough to the sun, so it is also slowly circling the sun due to the sun's gravity.It is still in the solar system.
Neptune image taken by Voyager 2
There may be one or two planets far away from Pluto, the farthest known planet, but so far there is no sign of their existence.However, it is quite certain that there are more than 100 billion small ice bodies comets far away from Pluto.These small ice bodies are calledAultCloud, this is based on the theory thatcometIt was named after the astronomer Olt who originated there.Around 26262, Voyager 2 will enterOort CloudAnd then it continued to pass through this cloud, lasting about 2400 years.Perhaps it seems to you that if Voyager 2 passes through an area containing 100 billion ice bodies, each of which has a diameter of at least 12 miles, it will surely hit one of them and be destroyed.In fact, this is not the case. The volume of the Oort Cloud is so huge that even if there are 100 billion such ice bodies slowly circling inside, the probability that Voyager 2 will hit one of them is actually zero.Around 28635, Voyager 2 will leave the Oort Cloud and enter interstellar space.After a million years of travel, Voyager 2 will be about 50 light years away from the sun (from the distance of the stars, it is almost still in people's own backyard).During this time, it is the same as any otherfixed starThe closest place is when it passes by Bilin Centauri, where it is only 3.21 light-years away from Bilin.In one million years, the distance from any star will never be less than 19 trillion miles, so the probability that any alien can encounter this small and silent detector in the remote space between stars is absolutely too small, and people need not worry about it.
However, in that case, if the message sent by people has no chance to be received by aliens, why do people send it.Remember, in the long history of the universe, a million years is only a short time.The universe has lasted 15000 1 million years and will continue to exist.There is no doubt that long after people disappear (frankly, even if there is no chance that human beings will last for ten million years, there is no doubt), someone will encounter this one daydetector。But if this is a long time after people disappear, who will care.OK, let's consider this problem.Do people want to disappear without leaving a trace.People are a little proud of being human.Certainly, people would like other intelligent creatures to know that people once existed here and know what people tried to do.
In May 2023, in the paper published in Geophysical Research Letters, astronomers believe that there is a polar vortex revolving around the north pole of Uranus.When NASA's Voyager 2 flew past Uranus decades ago, it found a vortex around its south pole.Astronomers carried out relevant research at that time and found that the temperature had not changed, so they thought that Uranus's atmosphere was quite inert.[9]
Voyager 2 space probe
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Multiple firsts
Voyager 2 is the only spacecraft to study all four giant planets in the solar system at close range.
Voyager 2 discovered the 14th moon on Jupiter.
Voyager 2 was the first man-made object to fly over Uranus.
Voyager 2 found 10 new moons and two new rings on Uranus.
Voyager 2 was the first man-made object to fly over Neptune.
Voyager 2 discovered five moons, four rings and a "big black spot" on Neptune[17]
Record setting
Voyager 2 set the first record for flying over Neptune.(Guinness World Records)[7]
From 1979 to 1989, NASA's Voyager 2 probe flew over four gas giant planets - Jupiter, Saturn, Uranus and Neptune.The Guinness World Period, which created the most visited spacecraftRecord.[10]
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Voyager 2 was launched from Florida in 1977 to study the outer solar system, Jupiter, Saturn, Uranus and Neptune.In 2018, Voyager 2 flew away from the solar wind layer, becoming the second probe to enter interstellar space after Voyager 1.[20]（Bloomberg News Review）
