A Jornada das Voyagers até os Confins do Universo

The Pale Blue Dot… This iconic image, which shows our planet from a distance of 6 billion kilometers, presents our world to humanity as a tiny and fragile point, almost imperceptible in the vastness of space, almost being eclipsed by a single beam of sunlight. The famous photograph was taken by the Voyager1 probe in 1990, at the request of astronomer and writer Carl Sagan, and is part of a set of photographs taken of the solar system, called family portrait. The Voyager 1 and 2 probes have an extraordinary legacy of providing an unparalleled view of the planets of the Solar System and beyond. With their discoveries and achievements, the Voyagers have become true ambassadors of humanity, taking us beyond our limits and revealing the secrets of the cosmos. Which you will learn about in this video, along with the history of the most distant objects ever built by humanity, so welcome to the infinite horizon. The Voyager program originated from another North American space program, called the Mariner program. Mariner was the first North American interplanetary exploration program, developed by NASA, with the objective of exploring the inner planets. Its mission consisted of the phased exploration of Mars, Venus and Mercury, through 5 distinct missions using 10 probes, of which 3 failed. The first mission of the Mariner program was launched in 1962, 7 years before the first man set foot on the Moon. In 1972, NASA began the program that would later become the Voyager program, in order to explore an exceptional planetary conjunction, which would allow probes to be able to fly over several planets with practically no fuel expenditure. 2 twin probes were built for this mission, called Mariner 11 and Mariner 12, but due to major differences from the original program, the mission was renamed Mariner Jupiter-Saturn. In March 1977, with the probes ready and just a few months before their launch, the program was renamed Voyager and the probes renamed Voyager 1 and Voyager 2 respectively. During the construction of the probes, renowned astronomer and scientific popularizer Carl Sagan proposed the idea of ​​including records of humanity in them. These records were inserted into the probes through golden discs, which are gold-plated copper discs that function as time capsules, designed as a message for possible forms of intelligent life that could encounter the probes in the future. Sagan led the committee responsible for selecting the discs’ content, whose goal was to create a comprehensive portrait of the diversity of life and culture on Earth. Each golden disc has 115 images of life on Earth, ranging from human anatomy to landscapes and animals on our planet, ambient sounds, 31 songs from different cultures and greetings in 55 different languages ​​— including a greeting in Portuguese. In addition, the gold discs contain diagrams and scientific information that seek to convey basic knowledge about mathematics, physics, biology and the location of the Solar System in the galaxy. Although the chances of the Voyager probes being encountered by some form of extraterrestrial life are remote, the golden discs are a symbolic reminder of our curiosity and our search for connection with the universe. They represent an effort to share a glimpse of what it is to be human and offer a glimpse of the diversity and creativity of our civilization. “The release of this ‘bottle’ into the cosmic ocean represents something very hopeful about life on this planet.”C. Sagan. Voyager 2 was launched on August 20, 1977, and Voyager 1 was launched on September 5 of the same year . The date was not chosen by chance: during that period of the North American summer, the four gaseous planets of the Solar System were aligned — a fact that only occurs every 175 years. This event was essential to the success of the mission, as it allowed the probes to be driven by the gravity of the planets, (greatly) shortening their travel time. Voyager 2’s trajectory was calculated to take advantage of this alignment, enabling the inclusion of the planets Uranus and Neptune in its mission. Already the Voyager 1 was launched with a trajectory that allowed it to reach Jupiter and Saturn first, including their moons Io and Titan, which would prevent a flight to the outer planets and Pluto, which at the time was still considered a planet. The initial objective of the probes would only be to study Jupiter and take advantage of its orbit to propel itself towards Saturn, so much so that, in their launches, the amount of fuel used in the rockets allowed them to reach a speed of around 45,000 km/h, just enough to reach Jupiter. In January 1979, Voyager 1 approached Jupiter and began photographing it, making its closest approach on March 5, reaching a distance of 349,000 km from the center of the planet. It was during this flyby that most observations of the planet were made. The probe was also able to capture images with greater resolution thanks to this approach. More than 19,000 images have been taken of Jupiter and its satellites. It was Voyager1 that transmitted the first detailed image of the great red spot, a gigantic storm larger than Earth, which has possibly lasted more than 300 years. One of the most surprising discoveries was the volcanic activity on Io, one of Jupiter’s moons, this was the first time that something like this had been detected outside of Earth. In July 79, Voyager2 made its approach to Jupiter, reaching a distance of 570,000 km from the planet. Together, the probes gathered data that greatly improved our knowledge about the Jovian system, about the Galilean moons, which are the four large moons: Io, Ganymede, Europa and Callisto, seen for the first time by Galileo Galilei, around the year 1610. They also detected rings around Jupiter, discovered three new satellites: Adrasteia, Metis and Thebe, which were the first Jupiter satellites discovered by a space probe. On Io, eruptions of nine volcanoes have been observed, some even reaching impressive heights. Already on Europa, data from the two probes indicate that the satellite may have oceans of liquid water beneath an ice crust. They also took the first close-up photos of the planet’s atmosphere, revealing that the large red spot is a complex storm that rotates counterclockwise, in addition to a series of smaller storms and formations throughout the atmosphere. In addition to the images, observations were also made of the gas giant’s magnetic field and radiation environment. After studying the Jovian system, the probes, using Jupiter’s orbit to gain momentum, headed to Saturn, with Voyager 1 making its closest approach on November 12, 1980, passing 124,000 km away from the planet’s upper cloud layers. Voyager 2 would arrive a few months later, in 1981. It was discovered that Saturn has the most devastating storms ever recorded until then, with winds that exceed over 5 thousand km/h. Thanks to the probes, scientists discovered that Saturn’s ring system is more complex than previously thought, in addition to the discovery of three new satellites: Atlas, Prometheus and Pandora. The spacecraft’s remote sensing instruments also studied the atmosphere of Saturn and its largest moon Tita. With the discovery of a dense, gaseous atmosphere on Titan the previous year, during the passage of Pioneer 11, Voyager mission controllers chose Voyager1 to approach Titan for a more detailed observation. With this change of direction, the probe would no longer be able to continue to the following planets Uranus and Neptune. Another option would be to use the effect of gravitational acceleration using the mass of Saturn to propel the ship to Pluto, but it was considered that the flyby of Titan had a greater scientific value and was less risky, ruling out the option for Pluto. Thanks to this maneuver, Voyager 1 was able to detect hydrocarbons under the dense tita atmosphere, which would in the future motivate the sending of a new probe to study the system on the Cassini-Huygens mission. Voyager 2, in turn, was not able to obtain detailed information about Titan, with a different trajectory, it passed over the plane of the rings and close to several moons such as Hyperion, Enceladus and Tethys, which it photographed in detail. She gained even more insight favorable of the fine structure of the rings, more complex than that revealed by Voyager 1. With the success of the first phase of the mission, Voyager 1 after the observations of Titan, ended the planetary phase of its mission, since with the change of route, the flyby by the satellite caused a gravitational deflection, and launched the satellite out of the ecliptic plane. From there, the ship would head out of the solar system and towards interstellar space. Voyager 2 went to Uranus again using the gravitational assistance method. In 1986, it flew by Uranus. He studied its rings and satellites, and discovered that the largest of them, Miranda, would have been hit by an object half the volume of the satellite. The shrapnel created the planet’s rings. In addition to the discovery of 11 more natural satellites, the probe also found that, in relation to other gaseous planets, Uranus’ atmosphere is serene. There are no storms beneath its clouds. The day on Uranus lasts 17 hours. This is because Uranus has an inclination angle of almost 90º, has its south pole pointed directly at the sun and rolls on its orbit instead of rotating along it. In other words, if Uranus could be inhabited, whoever lived in the dark part of the planet would always live in the dark, and whoever lived in the light part would always live under the Sun. In 1989, Voyager 2 passed by Neptune. The spacecraft discovered six new satellites, which brought Neptune’s total known satellites to eight, discovered a ring system, collected data on the planet’s dimensions, composition and magnetic field. She also discovered that the largest of the planet’s satellites, Triton, has a translation opposite to the planet’s rotation. Neptune is plagued by very strong storms, such as the great dark spot, a cyclone that circles the planet from time to time. In total, more than 10,000 images of the system were sent by the probe. When the Voyager mission was launched, the expectation was that the probes could reach at least as far as Jupiter. Voyager 2 would serve as a backup in case Voyager 1 failed in its mission. However, the two ships exceeded all expectations, successfully carrying out the first phase of the mission, which allowed the exploration of the planets Uranus and Neptune by Voyager 2. In August 1989, Voyager2 left Neptune’s orbit and headed towards the ends of the solar system, just like Voyager1. Thanks to the success of the mission and with all the planned objectives completed, in 89 the mission received new funding, starting the Interstellar Voyager Mission, but going back a little, to the year 1980, after Voyager 1 passed by Saturn, Carl Sagan proposed the idea of ​​the probe taking one last photo of the Earth. According to him, such a photo would not have great scientific value, since the earth would appear too small for the probe’s cameras to capture any detail, but even so, the image would be essential to have a perspective of our location in the universe. Many participants in the Voyager program supported the idea, but there were doubts whether taking a photo of the Earth so close to the sun would cause irreversible damage to the probe’s imaging system. The idea only began to be put into practice in 89, after the beginning of the interstellar phase of the mission, but the photo was only actually taken in 1990, in fact not just one photo, but a series of images showing the planets of the solar system and the sun, called family portrait, among them is the famous photo of the pale blue dot. After that, voyager1’s cameras were deactivated, since for the remainder of the mission, the probe would not go anywhere of photographic relevance, while the other data collection instruments would still need energy for the long interstellar journey. We can say that the pale blue dot was the last photo taken by the probe. Surprisingly, the probes are still in operation today, on the date of this video, 45 years after their launch, still sending data periodically to Earth, which are captured by the “PWS” plasma wave study system and sent to NASA. In 2013, NASA confirmed that the Voyager1 probe left the solar system and began to enter interstellar space, at a distance of approximately 19 billion kilometers from the sun. voyager2 has achieved interstellar space in 2020 is approximately 18 billion kilometers from Earth, even at this distance, it is still capable of communicating, receiving and executing commands from Earth. Despite all these years, the probes are still in operation due to the fact that several of their instruments have already been deactivated to save energy, including their cameras, with only what is essential for their operation remaining connected. But you may be wondering how it is still possible for there to be communication with the probes even with all this distance. Technically, there is no distance limit for communicating with the probes, because of their special antennas that can send signals at the speed of light, which travel infinitely through space, unlike the Wi-Fi signals we are used to here on Earth. What changes is the time it takes for these signals to get here and the time it takes for them to receive signals from here, which takes around 17 hours for each signal, due to the great distance. Although several instruments are now deactivated, the probes were able to make discoveries that help us better understand space beyond the limits of the solar system, such as the protective feature of the heliopause, a protective bubble generated by the sun, inflated by the wind of particles emitted by it, and which functions as a shield that protects the solar system from most galactic cosmic rays, one of the most energetic types of particles. In 2022, Voyager 1 puzzled NASA scientists with inaccurate information, which was classified as mysterious signals. The problem apparently was in the Articulation and Attitude Control System, whose information was being generated randomly, or which did not reflect any possible state that the system could be in. and precisely the precise functioning of this system that maintains the correct functioning of the probe’s antenna, which is always pointed towards the earth, NASA however stated that the signal had not weakened and that the antenna seemed to be in the correct position, as the signals were arriving. It was later discovered that the probe was sending data to an already inactive computer and this caused its data to be corrupted before it reached NASA. The problem was resolved, with the redirection of data sending to the right location, however, the reason for the probe to become disoriented in this way was not discovered. Voyager 1 is more than 23 billion km from Earth, in a region of space completely unknown to humanity, it has lasted much longer and flown much further than its creators could imagine, whether this event was caused by a failure of the probe itself or by some external interference, it is likely that we will never know for sure. It is estimated that communication with Voyager 1 will be lost this decade, around the year 2025, and Voyager2 in the 2030s, when its small nuclear reactors finally become incapable of generating the energy needed for the spacecraft’s most basic functions. When this happens, the ships will stop transmitting and fly in silence, possibly forever, if there is no physical impediment to them. As they travel to the farthest reaches of the known universe, they carry with them a time capsule, the golden disk, containing information about the diversity of life on Earth, our culture, science and technology. These records represent humanity’s courage, curiosity, and relentless pursuit of knowledge and exploration. It will take thousands or even millions of years for them to reach another star system, when that happens, we probably won’t be around for a long time. So, these lonely spacecraft will be a humble reminder of our ephemeral existence and the grandeur of the universe. As they continue to float in space, they carry with them the history of our species, and proof that we once existed, ready to be encountered by any form of intelligent life that might cross their path. Voyager’s journey is a testament to our ability to explore and our search for answers to the deepest questions about the universe. Even if they never let us see again, they will remain as silent ambassadors of humanity, taking our history and our curiosity beyond the limits of what we know. 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