Pictures from outside the solar system. Farewell photo of *Voyager. Images from Martian orbit

Saturn satellite system (montage)

The Voyager 1 spacecraft took the iconic "Pale Blue Dot" image back on February 14, 1990, which has become the most famous image of Earth from space. You can imagine the countless amount of footage this ship captured on its journey to interstellar space. These are just a few of the images that were received from Voyager 1 over the entire period of research. Quite recently, the spacecraft left the boundaries of our solar system.

Image of Saturn with a full disk of rings

Jupiter's Great Red Spot

Jupiter and its four moons, which are called the Galilean moons

Artist's representation of the distance scale in the solar system

Portrait of the Solar System - Earth approximately 4000 billion miles away

By today's standards, the technology on Voyager 1 was far from advanced, so all photographs were taken using analog film cameras and then scanned. The colors were created using a combination of mixing and digital manipulation.

Saturn's icy moon Rhea, whose surface is replete with craters

In September 2013, NASA's Jet Propulsion Laboratory (JPL) confirmed that Voyager 1 entered interstellar space on August 25, 2012. This probe became the first man-made object to penetrate such a remote area. NASA believes that the ship's power is sufficient to continue research activities until 2025. After this, Voyager 1 will continue its endless voyage throughout our Universe.

Voyager 1 tour (installation)

Saturn's ring system

Volcanic activity on Jupiter's moon Io

Arena of human passions. A ray of progress and the gray twilight of everyday life. Jerusalem and Mecca of all religions. Crusades, rivers of blood. Kings, courtiers, slaves. The illusion of grandeur and power. Crimes, wars and love. Saints, sinners and destinies. Human feelings, clinking of coins. The cycle of substances in nature. Hermit and superstar. Creators, ideological fighters - here everyone lived their time in order to disappear forever. Wealth, faith and the desire for unattainable beauty. Flight of hope, sunset of powerlessness. Dream castle in the air. And an endless series of news: birth, life - a game with death, a kaleidoscope of all coincidences, forward and upward! the cycle is completed. It's time to leave. And the light of other births is already dawning ahead. Civilizations and ideas.

The price of all this nonsense is one grain of sand in the void.

...On February 14, 1990, the cameras of the Voyager 1 probe received the last order - to turn around and take a farewell photograph of the Earth, before the automatic interplanetary station disappeared forever into the depths of space.

Of course, there was no scientific benefit in this: by that time, Voyager was already far beyond the orbits of Neptune and Pluto, 6 billion km from the Sun. A world of eternal darkness that is never warmed by the sun's rays. The illumination of those places is 900 times less than the illumination in Earth's orbit, and the luminary itself looks from there as a tiny shiny dot, barely visible against the background of other bright stars. And yet, scientists hoped to see an image of the Earth in the picture... What does the blue planet look like from a distance of 6 billion kilometers?

Curiosity took precedence over common sense, and several grams of precious hydrazine flew out through the nozzles of the vernier engines. The “eye” of the orientation system sensor flashed - Voyager turned around its axis and took the desired position in space. The television camera drives came to life and grinded, shaking off a layer of cosmic dust (the probe’s television equipment had been inactive for 10 years since parting with Saturn in 1980).

Voyager turned its gaze in the indicated direction, trying to capture the vicinity of the Sun in its lens - somewhere there should be a tiny pale blue dot rushing through space. But will it be possible to see anything from such a distance?

The shooting was carried out using a narrow-angle camera (0.4°) with a focal length of 500 mm, at an angle of 32° above the ecliptic plane (the plane of rotation of the Earth around the Sun). The distance to the Earth at this moment was ≈ 6,054,558,000 km.

After 5.5 hours, an image was obtained from the probe, which at first did not arouse much enthusiasm among specialists. On the technical side, the photo from the outskirts of the solar system looked like a defective film - a gray nondescript background with alternating light stripes caused by the scattering of sunlight in the camera optics (due to the huge distance, the apparent angle between the Earth and the Sun was less than 2 °). On the right side of the photograph there was a barely visible “speck of dust”, more like an image defect. There was no doubt - the probe transmitted an image of the Earth.

However, after disappointment came a true understanding of the deep philosophical meaning of this photograph.

Looking at photographs of the Earth from low-Earth orbit, we get the impression that the Earth is a large rotating ball covered with 71% water. Clusters of clouds, giant cyclone funnels, continents and city lights. A majestic spectacle. Alas, from a distance of 6 billion kilometers everything looked different.

« Everyone you have ever loved, everyone you have ever known, everyone you have ever heard of, every person who has ever existed lived their lives here. Our multitude of pleasures and sufferings, thousands of self-righteous religions, ideologies and economic doctrines, every hunter and gatherer, every hero and coward, every creator and destroyer of civilizations, every king and peasant, every politician and "superstar", every saint and sinner of our species lived here - on a speck suspended in a ray of sunshine"—Astronomer and astrophysicist Carl Sagan, commencement address, May 11, 1996.

It’s hard to imagine, but our entire huge, diverse world, with its pressing problems, “universal” catastrophes and upheavals, fit into 0.12 pixels of the Voyager 1 camera.

The figure “0.12 pixels” gives many reasons for jokes and doubts about the authenticity of the photo - did NASA specialists, like British scientists (who, as you know, divided 1 bit) managed to divide the indivisible? Everything turned out to be much simpler - at such a distance the scale of the Earth was really only 0.12 pixels of the camera - it would have been impossible to see any details on the surface of the planet. But thanks to the scattering of sunlight, the area where our planet is located looked like a tiny whitish speck with an area of ​​several pixels in the image.

The fantastic photograph went down in history under the name Pale Blue Dot (“pale blue dot”) - a stern reminder of who we really are, what all our ambitions and self-confident slogans “Man is the crown of creation” are worth. We are nothing to the Universe. And there is no way to call us. Our only home is a tiny point, already indistinguishable at distances over 40 astronomical units (1 AU ≈ 149.6 million km, which is equal to the average distance from the Earth to the Sun). For comparison, the distance to the nearest star, the red dwarf Proxima Centauri, is 270,000 AU.

Our posturing, our imagined importance, the illusion of our privileged status in the universe - they all give in to this point of pale light. Our planet is just a lonely speck of dust in the surrounding cosmic darkness. In this grandiose emptiness there is not a hint that someone will come to our aid in order to save us from our own ignorance.

« There is probably no better demonstration of stupid human arrogance than this detached picture of our tiny world. It seems to me that it emphasizes our responsibility, our duty to be kinder to each other, to value and cherish the pale blue dot - our only home" — K. Sagan, continuation of speech.

Another cool photo from the same series is a solar eclipse in the orbit of Saturn. The image was transmitted by the Cassini automatic station, which has been “cutting circles” around the giant planet for the ninth year. There is a tiny dot just visible on the left side of the outer ring. Earth!

Family portrait

Having sent a farewell picture of the Earth as a souvenir, Voyager simultaneously transmitted another interesting image - a mosaic of 60 individual images of various regions of the Solar System. Venus, Jupiter, Saturn, Uranus and Neptune “lit up” on some of them (Mercury and Mars could not be seen - the first was too close to the Sun, the second was too small). Together with the “pale blue dot,” these photographs formed the fantastic collage Family Portrait (“Family Portrait”) - for the first time, humanity was able to look at the solar system from the outside, outside the ecliptic plane!

The presented photographs of the planets were taken through various filters to obtain the best image of each object. The Sun was photographed with a darkening filter and a short shutter speed - even at such a gigantic distance its light is strong enough to damage telescopic optics.

Having said goodbye to distant Earth, Voyager's television cameras were completely deactivated - the probe forever went into interstellar space - where eternal darkness reigns. Voyager will no longer have to photograph anything - the remaining energy resource is now spent only on communicating with the Earth and ensuring the functioning of plasma and charged particle detectors. New programs aimed at studying the interstellar medium were rewritten into the on-board computer cells that were previously responsible for the operation of the cameras.

Photograph of the Sun by Voyager's wide-angle camera from a distance of 6 billion km. Two areas (not to scale) - the "pale blue dot" and Venus should be somewhere here

36 years in space

...23 years after the events described above, Voyager 1 is still floating in the void, only occasionally “tossing and turning” from side to side - the attitude control engines periodically counter the rotation of the device around its axis (on average 0.2 angular min. /sec), pointing a parabolic antenna towards the Earth, which had already disappeared from view, the distance to which had increased from six (as of 1990, when the “Family Portrait” was taken) to 18.77 billion kilometers (autumn 2013).

125 astronomical units, which is equivalent to 0.002 light years. At the same time, the probe continues to move away from the Sun at a speed of 17 km/s - Voyager 1 is the fastest of all objects ever created by human hands.

Before launch, 1977

According to the calculations of the creators of Voyager, the energy of its three radioisotope thermoelectric generators will last at least until 2020 - the power of plutonium RTGs decreases annually by 0.78%, and, to date, the probe receives only 60% of the original power (260 W versus 420 W at the start). The lack of energy is compensated by an energy-saving plan that provides for shift work and the shutdown of a number of non-essential systems.

The supply of hydrazine for the engines of the attitude control system should also be enough for another 10 years (several tens of kilograms of H2N-NH2 are still splashing in the probe’s tanks, from the 120 kg of the initial supply at the start). The only difficulty is that, due to the enormous distance, it is becoming increasingly difficult for the probe to find the dim Sun in the sky - there is a danger that the sensors may lose it among other bright stars. Having lost orientation, the probe will lose the ability to communicate with Earth.

Communications... it's hard to believe, but the power of Voyager's main transmitter is only 23 watts! Picking up signals from a probe from a distance of 18.77 billion km is the same as driving a car at a speed of 100 km/h for 21,000 years, without breaks or stops, then looking back and trying to see the light of a refrigerator light bulb burning at the beginning ways.

70-meter antenna of the Goldstone deep space communications complex

However, the problem was successfully resolved through repeated modernization of the entire ground receiving complex. As for all the seeming improbability of communication over such large distances, it is no more difficult than “hearing” the radiation of a distant galaxy using a radio telescope.

Voyager's radio signals take 17 hours to reach Earth. The power of the received signal is quadrillionths of a watt, but this is much higher than the sensitivity threshold of 34 and 70-meter “dishes” for deep space communications. Regular communication is maintained with the probe; the telemetry data transmission rate can reach 160 bits/sec.

Extended Voyager mission. At the boundary of the interstellar medium

On September 12, 2013, NASA announced once again that Voyager 1 had left the solar system and entered interstellar space. According to experts, this time there were no errors - the probe reached an area in which there is no “solar wind” (the flow of charged particles from the Sun), but the intensity of cosmic radiation has sharply increased. Moreover, this happened on August 25, 2012.

The reason for the uncertainty of scientists and the appearance of numerous false reports is the lack of operational detectors of plasma, charged particles and cosmic rays on board Voyager - the entire complex of probe instruments failed many years ago. Scientists' current conclusions about the properties of the environment are based only on indirect confirmation obtained by analyzing Voyager's incoming radio signals - as recent measurements have shown, solar flares no longer affect the probe's antenna devices. Now the probe's signals are distorted by a new sound that has never been recorded before - the plasma of the interstellar medium.

In general, this whole story with the “Pale Blue Dot”, “Family Portrait” and the study of the properties of the interstellar medium might not have happened - it was originally planned that communication with the Voyager 1 probe would cease in December 1980, as soon as it left the vicinity of Saturn, - the last of the planets he explored. From that moment on, the probe remained out of work - let it fly wherever it wanted, no scientific benefit was expected from its flight anymore.

The opinion of NASA specialists changed after becoming acquainted with the publication of Soviet scientists V. Baranov, K. Krasnobaev and A. Kulikovsky. Soviet astrophysicists calculated the boundary of the heliosphere, the so-called. heliopause - the region in which the solar wind completely subsides. Then the interstellar medium begins. According to theoretical calculations, at a distance of 12 billion km from the Sun, a densification should have occurred, the so-called. “shock wave” is the region in which the solar wind collides with interstellar plasma.

Interested in the problem, NASA extended the mission of both Voyager probes until the deadline - as long as communication with space reconnaissance is possible. As it turned out, it was not in vain - in 2004, Voyager 1 discovered the boundary of a shock wave at a distance of 12 billion km from the Sun - exactly as Soviet scientists predicted. The speed of the solar wind sharply decreased by 4 times. And now, the shock wave is left behind - the probe has entered interstellar space. At the same time, some oddities are noted: for example, the predicted change in the direction of the magnetic field of the plasma did not occur.

In addition, the loud statement about going beyond the Solar System is not entirely correct - the probe has ceased to feel the influence of the solar wind, but has not yet escaped beyond the gravitational field of the Solar System (Hill sphere) of 1 light year in size - this event is expected to occur no earlier than 18,000 years from now.

Will Voyager reach the edge of Hill's sphere? Will the probe be able to detect objects in the Oort Cloud? can he reach the stars? Alas, we will never know about this.

According to calculations, in 40,000 years, Voyager 1 will fly at a distance of 1.6 light years from the star Gliese 445. The further path of the probe is difficult to predict. In a million years, the hull of the starship will be distorted by cosmic particles and micrometeorites, but the space reconnaissance scout, asleep forever, will continue its lonely wandering in interstellar space. It is expected to live in outer space for about 1 billion years, remaining by then the only reminder of human civilization.

Voyager 1 was the first human-made probe to travel this far. It continues to fly forward at a speed of 17 kilometers per second, accelerated by several gravity maneuvers. The flight continues for almost 36 years

An image of the Earth taken by Voyager 1 in 1990 from a distance of 6 billion km

On board is the famous Golden Record, it is a copper information plate with recording of audio and video signals, packed in an aluminum case

78% of Voyager's recordings are dedicated to the musical expressions of many cultures.

The remaining 22% of the recording consists of human voices, various sounds of the Earth, and 116 images encoded as video signals. Human voices are recorded in the form of greetings from the UN Secretary-General in 55 of the most widely spoken languages ​​on Earth. The recording also includes 50 voices and sounds of the planet.

The plate also depicts the Earth as seen from space, using a photograph taken from low orbit. Atoms are shown schematically to familiarize yourself with the elemental composition of gases in our atmosphere.

2. In fact, two probes were launched into space for this purpose in 1977. This is the Voyager prototype at NASA's Jet Propulsion Laboratory in Pasadena, California. It was here that he successfully passed vibration tests in simulated outer space conditions.

3. Both nuclear-powered spacecraft reached Jupiter and Saturn, while Voyager 2 continued its journey to Uranus and Neptune.

4. On board Voyager 1 and Voyager 2 there are identical “golden plates” that carry information about the history of planet Earth into the depths of space. The 12-inch gold-plated copper discs contain greetings in 60 languages, samples of music from different cultures and eras, and some natural and human sounds.

5. Here is a selection of the best photographs taken over 33 years by Voyager 1.
February 1979: The probe completes docking with Jupiter in early April, taking nearly 19,000 images and many scientific measurements.

6. February 1979: This spectacular image of Jupiter's Great Red Spot was taken by Voyager 1 when it was 5.7 miles (9.2 km) from the planet.

7. Image of the atmosphere of Jupiter in false colors.

8. March 1979: This image was taken when Voyager reached Io, a satellite of Jupiter, equal in status to our Moon. The distance to it was approximately 490,000 km (304,000 miles). “It was beyond our imagination,” recalls Dr. Ed Stone, a research scientist on the program. It was then that scientists first saw active volcanoes on the surface of a planet in the solar system other than Earth.

9. March 1979: This photograph of Io was taken at a distance of 128,500 km (77,100 miles) away. The width of the painting is about 1,000 km (600 miles). The dissipating reddish-orange color probably corresponds to the locations of sulfur compounds, salt and other volcanic formations on the surface of the satellite. A dark spot with an uneven glowing pattern in the center of the image may be a volcanic crater covered with lava flows.

10. November 1980: Voyager 1 took its last look at Saturn after four days of orbiting the planet to capture the appearance of the planet and its rings from this unique perspective. Voyager discovered previously unknown needle-like structures on the rings, some of which are visible in the image as bright areas. The image was taken from a distance of 5.3 million km (3.3 million miles) from the planet.

11. October 1998: This collage shows Jupiter and its four moons, each the size of a planet. All of them are called Galilean satellites. The scale in this case is not observed, but the location relative to each other is real.

12. November 1998: Io's south polar region as seen by Voyager 1 as it orbits the planet's underside.

13. March 2000: Perhaps the most impressive of all Voyager's images of Io is this mosaic, visible from 400,000 km away.

14. Photo montage of images taken by Voyager: the planets and four satellites of Jupiter are located opposite the Rosette Nebula in a conventional color scheme, with the Moon in the foreground.

On September 5, 1977, the Voyager 1 interplanetary station was launched, the first spacecraft to enter interstellar space. Although its mission was supposed to last no more than five years, the probe is still operating and transmitting valuable information to Earth. Over the past time, the device has managed to move away from the surface of our planet to a distance of 139.6 astronomical units. This year we celebrate the fortieth anniversary of the launch of Voyager 1 and talk about the history of the project.

The idea of ​​the Voyager project was put forward by the NASA aerospace agency in the late 60s. IN 1976 A rare event for the solar system was about to happen - once every 177 years, Jupiter, Saturn, Uranus and Neptune find themselves on the same side of our star for three years, so that from Earth they are visible in a small area of ​​the sky. NASA engineers decided to use this phenomenon to launch two research stations to the gas giants - the favorable location of the planets allowed the probes to perform gravitational maneuvers and save fuel.

In 1977, Voyager 1 and its equally famous twin, Voyager 2, set off to explore then-little-explored worlds. Despite the number in the name, Voyager 2 was the first ship to be launched into space. The fact is that the probes had to fly around the giant planets from different directions in order to collect as much information about them as possible. Voyager 2 flew along the so-called slow trajectory and was supposed to approach all four planets, while Voyager 1 explored only Jupiter and Saturn and its path was noticeably shorter. Since scientists knew from the very beginning that the probe launched later would reach the asteroid belt between Mars and Jupiter earlier than its twin brother, they named it accordingly.

Before sending the Voyagers into outer space, NASA engineers considered more than 10 thousand possible flight trajectories, after which they chose only one (and, as it turned out, a successful one). However, even after such detailed preparation, many were not confident that the mission would be a success. Almost immediately after launch, Voyager 2 experienced technical problems, so engineers were in no hurry to send the second device into space. Voyager 1 was originally scheduled to launch on September 1, but was postponed twice. Despite the fact that NASA considers the probe’s flight “precise and flawless,” the memories of mission participants say otherwise. According to John Casani, the program's director, just after liftoff, he and Charles Colaise, Voyager's mission advisor and navigation expert, were in the control room at the Cape Canaveral launch center when they received poor readings from the Titan IIIE launch vehicle. Centaurus"). It seemed that Voyager 1 would not reach its goal. "I was scared. We were scared,” said Kasani. Colais turned to Kasani, who was sitting next to him: “John, we may fail. We don't have enough speed."

Titan's second stage fuel line developed a tiny, initially undetected leak that caused major problems during launch. Even if Voyager 1 reached the limits of Earth orbit, it might not be fast enough to successfully reach its next target, Jupiter.

However, the launch vehicle had a supply of fuel that could save the situation. The main danger was that empty fuel pumps could explode and damage Voyager 1 if the fuel were completely used up. However, Titan Centauri delivered the probe into orbit three seconds before it ran out of fuel, saving the mission.

Voyager 2

Voyager 2 launched from Cape Canaveral on August 20, 1977. Its flight trajectory made it possible to explore not only Jupiter and Saturn and their satellites, but also two other gas giants - Uranus and Neptune.

Voyager 2 became the first and only spacecraft to study all four outer planets of the solar system at close range. In addition, the probe photographed Ganymede and Europa, the Galilean moons of Jupiter - thanks to these images, scientists first hypothesized the existence of a liquid ocean beyond the Earth.

Voyager 2 also received images of the rings of Saturn and the surface of its moons, thousands of images of Uranus, its moons and rings, and unique photographs of Neptune. Now its mission, like that of Voyager 1, continues - the device is moving further and further away from us and is now studying interstellar space.

By the way, initially the Voyagers were supposed to become part of the Mariner program, which was engaged in the study of the inner planets, and be called Mariner 11 and Mariner 12, but the mission leaders eventually abandoned this idea. Later they wanted to give Voyager 1 the name Mariner-Jupiter-Saturn 77, or MJS-77. “I said, ‘Who cares about the start year of the mission anyway? We need a beautiful, catchy name,” says Kasani. - We held a competition. The main prize for the winner was a box of champagne.” This is how the name Voyager came about.

Since the program from the very beginning implied the exploration of distant planets, scientists could not install solar panels on the Voyagers - as they move away from the Sun, the intensity of its radiation decreases noticeably. For example, near the orbit of Neptune it is about 900 times less than that of the shaved Earth. Therefore, the sources of electricity in each of the probes are three radioisotope thermoelectric generators (RTGs) - they use plutonium-238 as fuel. At the time of launch, their power was approximately 470 watts; Since plutonium-238 has a half-life of 87.74 years, generators using it lose 0.78 percent of their power per year. As of September 3, 2017, Voyager 1 had 72.9 percent of its fuel reserves remaining. By 2050, capacity will be reduced to 56.5 percent.

A joint image of the Earth and the Moon taken from Voyager 1

A system of two television cameras is installed on board the spacecraft - wide-angle and narrow-angle. The resolution of a narrow-angle camera is enough to read a newspaper headline at a distance of one kilometer. It was thanks to this system that the spacecraft was able to obtain unique images of the Solar System. For example, two weeks after launch, Voyager 1 took the first ever joint portrait of the Earth and its moon.

In March 1979, the probe reached the outskirts of Jupiter. He photographed the famous Great Red Spot, the largest atmospheric vortex in the solar system, and also discovered volcanic activity on Io, one of the gas giant's Galilean moons. This was the first time that scientists were able to see active volcanoes somewhere beyond the Earth. In addition, Voyager 1 made another remarkable discovery - it saw the rings of Jupiter for the first time. Before this, it was believed that only Saturn and Uranus had a ring system.

An active volcano on Jupiter's moon Io, as seen by Voyager 1.

Voyager 1's next stop was Saturn with its famous system of rings and moons. The closest approach between the spacecraft and the planet occurred on November 12, 1980 - then the probe approached the upper layer of clouds at 64.2 thousand kilometers. He sent back to Earth the first high-quality images of rings made of fragments of ice, comets and dust, and also photographed some of Saturn's moons. The spacecraft discovered that the Cassini gap, first noticed in the 17th century, is also a kind of rarefied ring of ice and dust particles. At the same time, a thin and dim E ring was discovered. In addition, infrared and ultraviolet spectrometers installed on board Voyager 1 determined that the planet’s atmosphere consists almost entirely of hydrogen with helium impurities.

The main mission of the device ended with the study of Saturn and Jupiter, but it continued its space odyssey. In February 1990, Voyager 1 pointed its cameras at our planet and took a series of portraits of the solar system. At the same time, the famous Pale Blue Dot image was taken: it captured the Earth from a distance of 5.9 billion kilometers. The photo gets its name because our planet looks like a tiny blue dot in it; it occupies only 0.12 pixels in the image.

"Pale Blue Dot" from Voyager 1

Subsequently, the American astrophysicist and popularizer of science Carl Sagan wrote about this image in his book: “Look again at this point. It's here. This is our house. This is us. Everyone you love, everyone you know, everyone you've ever heard of, every person who has ever existed lived their lives on it.<...>every mother and every father, every bright child, inventor and traveler, every ethics teacher, every deceitful politician, every “superstar”, every “greatest leader”, every saint and sinner in the history of our species lived here - on a speck suspended in the sun. ray."

In February 1998, Voyager 1 overtook Pioneer 10 to become the most distant human-made object from us. Today, the probe is 139.6 astronomical units from Earth (or about 21 billion kilometers - or, to use another unit of measurement immortalized by Jules Verne in his novel, almost 3.76 billion nautical leagues) and continues to move towards the outer limits of the solar system at a speed of 16.9 kilometers per second. On board is a message to alien civilizations - one of the two gold records of Voyager. Carl Sagan and astronomer Francis Drake participated in its creation, who figured out how to use recording technology to engrave not only sounds and music, but also images on a record.

Both Voyagers carry one such golden plate with a message to other civilizations.

The message is a gold-plated copper disc housed in an aluminum case. It records all the most important information about our planet - its types, location relative to 14 powerful pulsars, the composition of the atmosphere, known life forms, the DNA molecule and the sounds of nature. The gold records also tell stories about us humans. If alien civilizations ever decipher the message, they will be able to learn about human anatomy, hear the cry of a child and the whisper of a mother, get acquainted with the music of Bach and Mozart and receive greetings in 55 languages, including Russian. Even when Voyager 1's engines stop working (this will happen in 2030), the golden records will float slowly through space, intact, for at least a billion years.

In December 2004, the Plasma Facility, another science instrument aboard Voyager 1, showed that the probe had crossed the heliospheric shock, the surface within the heliosphere at which the solar wind slows sharply to sonic speeds (relative to the speed of the Sun itself). This occurs due to the fact that a stream of charged particles “impinges” on interstellar matter, so the shock wave is considered one of the boundaries of the Solar System. The distance to the star at that time was 94 astronomical units.

The blue line in the blue zone on the graph shows how the density of charged particles should theoretically change at different distances from the Sun. Now the probe is in the blue zone, the graph also shows the moment of intersection of the heliospheric shock wave.

In December 2011, Voyager 1 moved to a distance of 119 astronomical units and reached the so-called stagnation region - the last frontier separating the probe from interstellar space. This region experiences a strong magnetic field because the pressure of charged particles from outer space causes the field created by the Sun to become denser. There is also an increase in the number of high-energy electrons (about 100 times) that arrive from the interstellar medium, so this region is also considered one of the boundaries of the Solar system.

In the first half of 2012, Voyager 1 reached the boundaries of interstellar space. The device's sensors recorded an increase in the level of galactic rays by 25 percent - this meant that the probe was approaching the boundary of the heliosphere. On September 12, 2013, NASA confirmed that Voyager 1 had left the heliosphere and was now in interstellar space. However, the device is still far from the hypothetical Oort cloud, the limit of the gravitational influence of the Sun.

All Voyager 1 scientific instruments will be turned off by 2025, after which only data on its technical condition will be received from the probe. Today, a signal from the space station takes 17 hours and 20 minutes to reach Earth. In the future, the mission program plans for another approach to a large celestial body - however, it will not happen soon, only after 40 thousand years. The spacecraft will fly within 1.6 light years (15 trillion kilometers) of the star AC+79 3888 in the constellation Giraffe; however, by that time we will no longer be able to receive any data from Voyager 1. After this, the probe will continue to wander through the Milky Way, moving further and further away from its home - Earth. It is collected by the New Horizons interplanetary station, launched by NASA in 2006.

Now this probe, like Voyagers, is moving towards interstellar space, but is much closer to the Sun - at a distance of 39 astronomical units - and flies much slower, despite its higher launch speed. This is due to the fact that Voyager 1 managed to gain additional speed due to a gravity assist maneuver near Jupiter. In addition, the power of the New Horizons station engines is inferior to the power of the Voyager engines, so it will not be able to break the distance record of the twin probes - when the spacecraft stops its work in the 2020s, the total length of its path will be 50–55 astronomical units.

Kristina Ulasovich