40 years through the universe!Human farthest detector is about to usher in the final farewell

The following article comes from WeChat public account: Global Science, author Global Science

"Traveler" 1 and 2 detectors have been flying in the solar system for more than 40 years. Today, they have flew out of the Japanese goal and become the only two artificial objects that enter the interstellar space. With electrical failure, researchers have to gradually close the instrument of the "Traveler" and plan to end this task in the 1930s. Since then, they will lose contact with the earth and open endless interstellar wandering.

In this section selected in the new article of "Global Science" in August, Tim Folder will take us back to the long, wonderful and harvest journey that the "Traveler" has experienced, but this voyage may may Finally reached the end.

Written article ｜ Tim Folger (Tim Folger)

Translation ｜ Ding Yi

If the stars are not arranged, the most outstanding spacecraft will never take off. The stars mentioned here are actually the planets -the largest planets in the solar system (Jupiter, Saturn, King of Heaven, Neptune). About 60 years ago, these four planets slowly formed a special arrangement, and the last time this happened, in the early 19th century, Thomas Jefferson served as President of the United States. For a long time, this rare planet's arrangement has almost did not attract attention. The first person to notice this phenomenon was a doctoral student of aviation, named Gary Flandro, who was studying at the California Institute of Technology.

In 1965, the era of space exploration just started -the Soviet Union launched the first artificial satellite "Sputnik 1" 8 years ago. At that time, Frandro was working part -time in the US Aerospace Administration (NASA) Jet Promotion Laboratory (JPL) in California. His task was to find the most effective way to send the space detector to Jupiter. , King Star or Neptune. He used the 20th -century engineer's favorite precision tool -pencil -drawing the sports trajectory of these giant planets and discovered a wonderful thing: in the late 1970s and early 1970s, these four planets will be It will form a celestial necklace like pearls to form a long arc with the earth.

This coincidence means that the spacecraft can accelerate from the gravity of giant stars when each giant planet. This is like the intangible rope of the traction detector breaks in the last second, throwing the detector forward. Calculated by Frandro, this so -called repetitive gravity can promote the flight time between the detector between the earth and the Neptune from 30 years to 12 years. To achieve this, you must seize the opportunity, because this phenomenon of planetarian beads only occurs every 176. In order to reach the target planet when the "Four -Star Beads" occurred, scientists must launch a detector in the mid -1970s.

Journey of the "Traveler"

Obviously, NASA wants to take advantage of this century -old opportunity, so they designed two spacecraft- "Voyager 1" (Voyager 1) and "Voyager 2). These two aerospaces were exactly the same and were launched one after another in the summer of 1977. The "Traveler" has been flying in space for nearly 45 years and is still running. It spreads data from the planet far away from the solar system to the earth every day. They fly farther than any other spacecraft in history and longer work. Moreover, according to scientists' understanding of the range of Japanese goals, the "Traveler" has entered the interstellar space of the galaxy. They are the first batch of artificial objects that arrive there and will continue to maintain this award in the next decades. Initially, the "Traveler" mission plan lasted only 4 years. As far as this is concerned, the existing record is pretty good.

In the early exploration of 40 years ago, the "Traveler" allowed researchers to see Jupiter's satellites at close range for the first time. These satellites have live volcanic and icefrains, which surprised them. Astronomers originally thought that these satellites would be as angry as the moon, and the surface was located on the surface. In 1986, "Traveler" 2 became the first spacecraft to fly the king star; three years later, it flew over Neptune again. So far, it is the only spacecraft to complete this travel. Now, the "Traveler", a pioneer of interstellar detectors, has more than 19.3 billion kilometers from the earth. A series of unexpected discoveries obtained in the unknown Star Space make the theoretical astronomers excited and confused.

"Traveler" No. 2 was tested in NASA Jet Prosperity Laboratory.

However, the wonderful journey of the "Traveler" will end. Beginning this year, NASA plans to close some systems of the "Traveler" to maintain the remaining energy reserves and extend their unprecedented journey to about 2030. For those scientists who work for the "Traveler" project from the beginning, this is a moment of bitterness. This project far exceeding their expected project is about to end now.

"We have worked for this project for 44 and a half years, which is equivalent to extending the warranty period of the spacecraft to 10 times that of the original plan." Physicist Ralph at the Applied Physics Laboratory (APL) of John Hopkins University in the United States Ralph McNutt said. Most of his career is studying the "Traveler". Flying to interstellar space

At present, the two "Traveler" detectors are very far away from the earth. The unidirectional radio signal that is transmitted at a speed of light takes nearly 22 hours to catch up with the "Traveler" No. 1. number 2. Every day they fly 3 to 4 lights. The only connection between the "Traveler" and the Earth is the Deep Space Network of NASA. This is a network composed of three tracking complexes distributed around the world. Communication. As the "Traveler" is getting farther and farther in space and time, their signals are getting weaker. Glen Nagle, a deep space detection network and a communications manager in Canberra, Australia, said: "The earth is a noisy place, radios, TV, mobile phone ... Receive the faint signal from the "Traveler". "

In 1993, the distance between Genite's distance between the interstellar space, the distance of the so -called Japanese gallery top, calculated, and set the distance between the top of the Japanese ball layer to 116 to 177 astronomical units (AU, 1AU refers to the average distance from the earth to the sun, which is equivalent to 150 million kilometers), which increases to about 25 times the original. He said that these estimates did not be recognized by peers. As of 1993, the flight mileage of "Traveler" 1 has reached 50AU. "If the top distance of the Japanese ball layer is 120AU, this means that the" Traveler "will still fly 70AU again." If Genite's estimation is correct, then the "Traveler" is about 3.5AU/year forward speed, at least at least, at least at least Within 20 years, the "Traveler" will still not leave the Japanese goal.

In the 45 years after launch in 1977, the "Traveler" went to the cosmic space that the artificial detector had never reached.

This prediction brings a worrying question: Can the US Congress support the "Traveler" mission for a long time? The funding for this task has been extended, and the scientist expects the task to end at about 50AU, that is, when the "Traveler" crosses the Japanese ball top. However, the "Traveler" has already flew through the Milestone of 50AU, but did not find any expected interstellar space boundary. Astronomers have imagined that the "Traveler" will detect the sudden enhanced galaxy cosmic line -high -energy particles like shells, like the speed of light at a speed of light or other deep space bangs. Magnetic Cocoon formed by the Japanese goal layer will make most of the low -energy universe lines biased before reaching the solar system. Stone said: "The Sun Magnetic Cocoon has shielded at least 75%of the external universe line for us."

The ground team of the "Traveler" is also waiting for the detector to record signs of the leading magnetic field transformation. Scientists believe that the interstellar magnetic field is generated by nearby stars and huge ionized gases, and it is likely to be different from the magnetic field of the Japanese ball layer. However, the "Traveler" has not been detected so far.

In November 2018, when the "Traveler" arrived on the interstellar boundary, it failed to detect changes in the magnetic field. And this spacecraft raised another problem: it encountered the top of the Japanese ball layer at a place 120AU from the Earth -the top distance from the Japanese goal layer recorded 6 years ago "Traveler" 1. This result does not match the predictions of any theoretical model. All theoretical models believe that the Japanese bete -ups should be expanded or contracted synchronously with the 11 -year cycle of the sun. During this period, the sun wind was undulating. When the "Traveler" arrived on the 2nd, the solar wind was at its peak period. If the theoretical model was correct, the solar wind should push the Japanese ball to a farther place than 120AU. "This is something that all theoretical physicists did not expect. From the perspective of the discovery of the" Traveler ", there are still insufficient theoretical models."

How long can the "Traveler" run?

The service life of some things is not as good as their hardware life, and finally it becomes a collectible -recording machine, video recorder and coins. The "Traveler" is not the same. They use the technology 50 years ago to complete the task far exceeding the design life. "The number of software on the" Traveler "instrument is small, and there is no computer micro -processor at that time!" Crimirgis said. The designer of the "Traveler" cannot use thousands of lines to help operate the spacecraft. "In general, I think the reason why the" Traveler "mission can last so long is because almost everything is connected by hardware. Today's engineers don’t know how to do this. . I don't know if it is possible to build a concise spacecraft like the "Traveler". The "Traveler" will probably be the last. "

It's not easy to say goodbye to these pioneering detectors. "We don't want to see the end of the task," said Kaminus, "But the" Traveler "detector has achieved quite amazing achievements. We could not reach the top of the Japanese gallery, but now it has been done." There are still 5 normal operations on the "Traveler" No. 2, and there are 4 "Traveler" No. 1. All these instruments are provided by a device, which can convert the heat generated by radioactive decay into electrical energy. But as the output power decreases by about 4 watts per year, NASA has to adopt a diversion mode. Two years ago, the engineer of the "Traveler" task closed the heater of the cosmic line detector, which is a key device that determines the top of the Japanese ball. Since the "Traveler" has reached the top of the Japanese goal layer, everyone thinks that the instrument will stop operation.

"The temperature here dropped by about 60 ~ 70 ° C, far exceeding the design operation limit of any instrument, but the cosmic line detector has been working normally. This is incredible."

The two instruments that were stopped at the end of the "Traveler" were likely to be magnetic meters and plasma science instruments. They are packed in the ship's hull, and the calories emitted by the computer to keep them warm. Other instruments are hung on a 13 -meter -long glass fiber boom. Dort said: "When the heater is closed, all instruments will become very, very cold."

Even after the "Traveler" is in a completely silent state, their flight journey will continue. 16700 years later, "Traveler" 1 will go through the nearest star, half a horse is neighbor. After 3600 years, "Traveler" 2 will follow. The "Traveler" will continue for millions of years in the Milky Way. Even if our sun collapses in the future, and the Japanese stratum is no longer exist -not to mention our earth -the "Traveler" will still be traveled in the Milky Way almost in the Milky Way. Perhaps at some time in the future, the "Traveler" will successfully spread the last message. This information will not be transmitted by radio. If it can be received, the receiver must not be humans.

This article is selected from "Global Science" in August 2022, "Traveler": Last Farewell.

This article is authorized to reprint from WeChat public account: Global Science Author: Global Science

Reprinted content only represents the author's point of view

It does not represent the high energy office of the Chinese Academy of Sciences

---

Edit: Photon

---

- END -