Which country is the "Voyager" series of detectors?

Voyager 1 is an unmanned outer solar system space probe manufactured and launched by NASA. The detector weighs 8 15 kg and was launched on September 5, 1977. Until 2006, it was still running normally. It has visited Jupiter and Saturn and is the first spacecraft to provide high-resolution and clear photos of its satellites. It is the man-made aircraft farthest from the earth so far. Its flying speed is a little faster than any man-made spacecraft at present, and its life has also benefited from several gravitational accelerations. As of 2006, Voyager 1 has reached the outermost boundary of the solar system and will soon fly out of the solar system.

Schematic diagram of "Voyager 1"

As of April 4th, 2007, "Voyager 1" is at a distance of 15. 18 meters from the sun (i.e.15.18×1012 meters or/. If Voyager 1 can still operate effectively after leaving the heliosphere, scientists will have the first opportunity to measure the actual situation of interstellar matter. According to the current position, the signal sent by the spacecraft needs more than 13 hours to reach its control center, the Jet Propulsion Laboratory, which is jointly operated by NASA and California Institute of Technology in Pasadena, California. Voyager 1 is flying in a hyperbolic orbit and has arrived in third cosmic velocity. This means that its orbit can no longer guide the spacecraft back to the solar system. Like Pioneer 10, Pioneer 1 1 and its sister ship Voyager 2, it became a starship.

In fact, Voyager 1 originally aimed at detecting Jupiter and Saturn and their satellites and rings, but now its mission has been changed to detect the top layer of the solar wind and make particle measurements of the solar wind.

In fact, the two Voyager probes are powered by three radioisotope thermoelectric generators. At present, these generators have greatly exceeded the original design life, and it is generally believed that they will still provide enough power to enable the spacecraft to continue to contact the Earth before about 2020.

Voyager 1 originally planned to be a sailor in mariner program 1 1, and its design adopted the new technology of gravity acceleration at that time. Fortunately, this mission happened to meet the once-in-a-lifetime planetary geometric arrangement of 176. The spacecraft only needs a small amount of fuel for channel correction, and the rest of the time can be accelerated by the gravity of each planet. Spacecraft can visit four gas planets in the solar system: Jupiter, Saturn, Uranus and Neptune. 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. Because of this opportunity, it only takes 12 years for two spacecraft to visit four planets, instead of 30 years.

1 97965438+1October, Voyager1captured Jupiter for the first time. Because it was closest to Jupiter on March 5 of the same year, it was only 349,000 kilometers away from the center of Jupiter. Therefore, during the 48-hour short flight, the spacecraft can deeply understand Jupiter's satellites, rings, magnetic fields and radiation environment, and take high-resolution photos.

After the "Free Travel" probe successfully used Jupiter's gravity, the spacecraft began to head for Saturn. Voyager 1 passes Saturn in June 1980, June 1 1, and June1/is closest to Saturn. The spacecraft explored the complex structure of Saturn's rings and observed the atmosphere on Titan. Because Titan 6 was found to have a dense atmosphere, the controllers of the Jet Propulsion Laboratory finally decided to let Voyager 1 approach Titan 6 for research, and then prevented it from continuing to visit the other two planets. Therefore, the mission to visit Uranus and Neptune had to be handed over to Voyager 2. The decision to approach Titan 6 caused the spacecraft to be affected by extra gravity, which eventually made the spacecraft leave the ecliptic and terminated the mission of exploring planets.

It is worth mentioning that "Voyager 1" carried a brass disc with greetings and various music recorded in 55 human languages to express human greetings to "aliens". The record has a thickness of 12 inch, a gold-plated surface and a stylus inside. These 55 human languages include Akkadian in ancient Mesopotamia and other very obscure languages, as well as four Chinese dialects (Mandarin, Xiamen dialect, Cantonese and Wu dialect). The greeting is: "The children of the earth say hello to you". In addition, the record also includes the following contents:

Kurt waldheim, the fourth Secretary-General of the United Nations.

Greetings from then UN Secretary-General kurt waldheim.

At that time, President Carter's greeting was: "This is a gift from a distant small world. It records our voices, our science, our images, our music, our thoughts and feelings. We are trying to live our time and enter your time. "

Carter, then president of the United States

In addition, it also includes a 90-minute vocal music collection, which mainly includes various sounds of the earth and nature and 27 world-famous songs, including Chinese Peking Opera and the ancient song "Mountain Flowing Water", Mozart's "Magic Flute" and Japanese shakuhachi. In addition, there are 1 15 images, planets of the solar system images, images and descriptions of human reproductive organs, etc.

1977 On August 20th, NASA launched an unmanned spacecraft "Voyager 2". It has basically the same design as its sister ship Voyager 1. The difference between the two is that Voyager 2 follows a slow flight path, so that it can stay on the ecliptic (that is, the orbital height of the planets in the solar system), thus accelerating its flight to Uranus and Neptune in 198 1 with the help of Saturn's gravity. Because of this, it is not as close to Titan as its sister star Voyager 1. However, it became the first spacecraft to visit Uranus and Neptune, and at 176, it seized the once-in-a-lifetime opportunity of planetary geometric arrangement and visited four planets.

Voyager 2 spacecraft

In fact, Voyager 2 is considered to be the most prolific spacecraft launched from the earth. The reason why scientists make this evaluation is mainly because NASA can still visit four planets and their satellites with powerful cameras and a large number of scientific instruments, even though it has tightened its spending on Galileo and Cassini-Huygens' follow-up plans.

According to the data,1July 9, 979, Voyager 2 was the closest to Jupiter, passing 570,000 kilometers from the cloud top of Jupiter. During this visit, I accidentally discovered several rings around Jupiter and took some photos of Io 1 to show its volcanic activity.

As we know, Jupiter is the largest planet in the solar system, which is mainly composed of hydrogen and helium and a small amount of methane, ammonia, water vapor and other compounds, with a core composed of silicate rocks and iron in the center. The colorful clouds on Jupiter show the unpredictable weather in Jupiter's atmosphere. Jupiter's period of revolution is 1 1.8 years, and its rotation period is 9 hours and 55 minutes.

Although astronomers have been studying the planet through telescopes for centuries, the discovery of Voyager 2 still surprised scientists. For example, the famous Great Red Spot storm in Jupiter's atmosphere was found to be a complex storm system rotating counterclockwise. At the same time, some small storms and eddies were found.

Another thing that shocked scientists was the discovery of an active volcano on Io 1. This is because scientists have discovered active volcanic activity in other stars in the solar system for the first time. This time, Voyager 2 observed 9 volcanic eruptions on Io 1 and confirmed other volcanic eruptions during the visit of two Voyager spacecraft. According to relevant data, the smoke generated by volcanic eruption was sprayed into the sky more than 300 kilometers (1 90 miles) from the surface of Io. The velocity of material ejected by volcanic eruption is as high as 1 km/s, and scientists believe that the volcanic eruption energy on Io 1 may come from the tidal force between it and Jupiter, Europa and Callisto. Because these three satellites are locked in Laplace resonance orbit, that is, Europa 1 rotates twice, and Europa 2 rotates once; When Europa rotates twice, Ganymede will rotate again. In fact, although Io 1 always faces Jupiter, Europa and Ganymede make it swing slightly. This rocking force is so great that Io 1 bends to 100 m (330 feet), but it is only 1 m (3 feet) relative to the earth. Facts show that the volcanic activity on Io 1 also affects the whole Jupiter system, and its influence covers Jupiter's magnetosphere. The volcano on Io 1 obviously spewed out sulfuric acid, oxygen and sodium, and the satellite surface was also splashed by high-energy particles. These splashes even reached the magnetospheric boundary of Io 1, millions of miles from its surface.

As for Europa, from the low-resolution photos of Voyager 1, we can see that its surface has criss-crossing textures. At first, scientists thought that those textures were cracks caused by crustal movement or tectonic activity. However, the high-resolution photos provided by Voyager 2 later annoyed scientists because those features lacked topographic contours. A scientist once described it like this: "Those features are like a thick stroke." So, what is the reason for such a line? Scientists believe that it may be because Europa is also affected by tidal force, which produces friction and heat in it, such as Europa 1 10% or less. It is generally believed that Europa has a thin ice shell (less than 30 kilometers or 18 miles) and an ocean about 50 kilometers (30 miles) deep.

We may know that Ganymede is the largest natural satellite in the solar system, with a diameter of 5,276 kilometers (3,280 miles). Voyager 2' s voyage also confirmed that there are two obvious landforms on Ganymede: many pits and many deep ditches. Scientists believe that the ice crust of Ganymede is being affected by the tension of crustal tectonic activity.

Relatively speaking, the ancient craters left on Callisto's crust show many traces of being hit by meteorites. According to the data analysis, scientists pointed out that the largest crater on Callisto was obviously filled by time due to the movement of ice on the earth's crust, because the basin full of impact marks left almost no obvious topographic features.

In addition, Voyager 2 also found that Jupiter has a dim powdery ring. According to scientists' calculations, the outer edge of the ring is 129000 km (80000 miles) from the center of Jupiter, while the inner boundary is 30000 km (18000 miles) from the center of Jupiter. At the same time, this trip also found two tiny satellites, Io 15 and Io 16, which are just outside Jupiter's ring. The third newly discovered satellite, Io 14, is sandwiched between Io 5 and Io 1.

It is found that Jupiter's rings and moons both appear in its dense magnetic field, which is full of electron and ion radiation belts. These particles and the magnetic field form Jupiter's magnetosphere, which extends 3-7 million kilometers towards the sun, at least reaching Saturn's orbit, that is, 750 million kilometers (460 million miles). Because the magnetosphere will follow Jupiter's rotation, the magnetosphere will peel off 1 ton of matter every second while sweeping Io. These substances will form an annular ion cloud that can only be seen under ultraviolet light, and this ion cloud will move outward, making Jupiter's magnetosphere twice as large as normal. And some high-energy sulfuric acid and oxygen ions will fall into this magnetic field, and then enter Jupiter's atmosphere to form aurora.

1981On August 25th, Voyager 2 was the closest to Saturn. When the spacecraft is behind Saturn (relative to the earth), it uses radar to detect Saturn's upper atmosphere and measure its temperature and density. Voyager 2 found that the upper temperature (when the air pressure is equivalent to 700 Pa) is 70 Kelvin (-203℃), while the lower temperature (when the air pressure is equivalent to 12000 Pa) is 143 Kelvin (-130℃).

After passing Saturn, the shooting platform on the ship got stuck, which led to the change of the mission to Uranus and Neptune. Fortunately, the staff on the ground finally solved the problem. In the end, the spacecraft was still instructed to move on to Uranus.

According to the data, the closest location of Voyager 2 to Uranus is198665438+1October 24th, and then 10 previously unknown natural satellites were discovered. In addition, the spacecraft also explored the original and unique atmosphere of Uranus and observed its planetary ring system.

As we know, Uranus is the third largest planet in the solar system, and its rotation distance around the sun is about 2.8 billion kilometers. Its period of revolution is 84 years and its rotation period is 17 hours 14 minutes. Interestingly, Uranus' rotation is a bit unique, mainly because it actually rolls in orbit. It is generally believed that this unusual position is due to its collision with a planet-sized star in the early stage of the formation of the solar system. In view of its strange positioning, its poles will receive day or night for 42 years respectively, so scientists don't know what they will find on Uranus.

In addition, Uranus' radiation belt was found to be as dense as Saturn's. The radiation intensity of the radiation belt will dim the light quickly (within 100000 years) and any methane trapped on the ice in the satellite or ring. This explains why most of Uranus' moons and rings are mainly gray.

Voyager 2 also detected some high-level fog at the pole of direct sunlight, and found that these fog helped to spread a lot of ultraviolet rays. Scientists call this phenomenon "solar glow", and its average temperature is 60 K (-350 F). Surprisingly, even the bright and dark poles are almost the same in cloud top temperature on the whole earth.

1On August 25th, 989, Voyager 2 approached Neptune. Since this is the last planet that Voyager 2 can visit, scientists decided to adjust its course to make it closer to Triton 1, thus ignoring its flight path, just as Voyager 1 ignored its flight path after visiting Saturn to conduct research near Titan 6.

This time, Voyager 2 accidentally discovered Neptune's big dark spot, but when Hubble Space Telescope observed it again in 1994, the dark spot disappeared. At first it was considered as a big cloud, and later it was considered as a hole in the cloud.

After Voyager 2 visited Neptune, Pluto was the only planet that had not been visited by any spacecraft from the earth. But later, after the International Astronomical Society redefined the planet, Pluto was downgraded to a dwarf planet. Therefore, the passage of Voyager 2 in 1989 made all the planets in the solar system visited by man-made spacecraft at least once.

In addition, Voyager 2 also flew to Triton 1, and found that Triton 1 is indeed the only large satellite in the solar system that retrogrades in the direction of planetary rotation, and it is also the coldest celestial body in the solar system, but it is brighter, colder and smaller than scientists originally thought. The surface temperature is -240℃, and some areas are covered with water, snow and ice, and it often snows. There are three mountains of ice and fire, and frozen methane or nitrogen ice particles have been ejected, sometimes reaching a height of 32 kilometers. After analysis, scientists pointed out that there are probably liquid nitrogen oceans, glacial lakes, faults, mountains, canyons and glaciers on Triton 1. This indicates that a similar earthquake may have occurred on Triton 1. There is a thin atmosphere composed of nitrogen on Triton 1, and its polar cap is composed of frozen nitrogen, forming a dazzling white world.

On September 5, 2006, Voyager 2 was about 80.5 astronomical units (about 12 meters) away from the sun, and went deep into the ecliptic discrete celestial body, advancing at a speed of 3.3 astronomical units per year. This distance is twice the distance between the sun and Pluto, and the perihelion of Viced is far away, but it still does not exceed the farthest orbit of Eris.

Scientists finally pointed out that Voyager 2 will continue to transmit signals until 2020.