The Clipper spacecraft, which NASA will send to Europa, one of Jupiter's most interesting satellites in terms of the search for life, will carry a plaque on which the phrases of the word water have been represented in 103 languages. The design of the sheet, which is also engraved with the equation devised in the 1960s by the pioneer in the search for extraterrestrial life, Frank Drake, with the aim of calculating the number of advanced civilizations existing in the galaxy, has involved the organization METI (the acronym in English for Messages to Intelligent Extraterrestrials).
This is not the first time that messages have been sent aboard space probes that could one day be received by hypothetical cosmic civilizations. But in this case, the main recipient would be humanity itself in the distant future. The Clipper probe, once its mission ends in 2034, could survive and remain in Jupiter's orbit, so that the information contained on the ship's plate would be a kind of time capsule with which future humans would acquire a greater knowledge about his past.
Clipper is one of the most anticipated space exploration missions in recent years. Their destination, Europa, is a world covered by a thick layer of water ice under which an immense liquid ocean is housed. The spacecraft is scheduled to reach Jupiter's orbit in 2030.
The plate that the Clipper mission will transport is made of metallic tantalum, measures 18 by 28 centimeters and 1 millimeter thick, and will protect some of the ship's electronic components from the powerful radiation generated by Jupiter.
The central element on which the information that appears on the sheet pivots is water. The limited knowledge we have about life assigns this compound an essential role, and in fact the phrase “let's follow the water” has been the mantra that has guided the main scientific initiatives in the search for life outside Earth. In this sense, some of the moons of Jupiter and Saturn have become priority objectives for space exploration.
For this reason, and for its flagship mission to Europa, Jupiter's satellite, NASA has chosen to sculpt with laser, on the Clipper plate, the sound representation of the word water pronounced in 103 languages, including Spanish, Catalan and Basque.
The utterances, performed by native people, have been transformed and drawn in their wave format, radiating from a center in which a circular symbol representing water in American Sign Language is displayed.
The so-called Drake equation also appears on the Clipper sheet, the formula created by Frank Drake, the founder and president of SETI (an organization that promotes the search for extraterrestrial intelligence), to estimate the number of civilizations that could exist on Earth. galaxy.
Likewise, the emission frequencies of two chemical entities that are especially relevant with regard to space transmissions and that also make up water are represented: hydrogen, H, and the hydroxyl molecule OH. Precisely the radio frequencies that are between those of these compounds are considered optimal to be able to receive signals from possible civilizations.
Once Clipper finishes its exploration of Europa, in 2034, NASA expects the ship to crash into Ganymede, another of Jupiter's satellites and the largest in our solar system. However, there is a possibility that it will enter a stable orbit in the vicinity of the gaseous planet and survive for millennia.
Thus, unlike messages sent aboard probes that travel to outer space, Clipper's message would remain inside the solar system hoping that, perhaps one day, it could be recovered by humanity.
As stated by Douglas Vakoch, president of the organization METI (Messages to Intelligent Extraterrestrials) and designer of the information carried by the Clipper spacecraft, the data could be very useful for humans of the future, who would predictably have a cultural baggage radically different from the current one. According to Vakoch, if the ship were captured in the future and the messages were interpreted, “we would have managed to communicate a few scientific concepts through time, space and language.”
The moon Europa is one of the priority objectives of space exploration and the search for life outside Earth. The data collected by previous space missions reveal the more than probable existence of an ocean of liquid water beneath the global layer of ice that covers the entire satellite.
In fact, the figures being considered for Europe are impressive for a body that is only a quarter of the Earth's diameter: its ice cover could be up to 25 kilometers thick, and the underground sea, with a depth of between 60 and 150 kilometers, it would contain more than twice all the water on Earth.
But there is also a suspicion that Europa could eject water vapor into space. This possibility, fueled by observations made by telescopes and also from new interpretations of data collected by previous missions, would facilitate the exploration of this world, since these water emissions could be analyzed to understand the composition of the interior ocean.
The Clipper mission will begin its journey next October. After two close passes to gravitationally bounce off Mars (2025) and our planet (2026), it will enter Jovian orbit in April 2030, and is expected to make its first close pass by Europa during the spring of 2031.
The practice of sending information intended for other civilizations began in the 1970s with the NASA spacecraft Pioneer 10 and 11. Each carried golden plates with various physical data engraved on their surface (including the figures of a woman and a man). , these probes became the first to visit the orbit of Jupiter (Pioneer 10) and Saturn (Pioneer 11) and to subsequently head towards the confines of the solar system with sufficient speed to escape the attraction of the Sun and continue his journey through space.
The famous Voyager, launched in 1977 and currently the most distant spacecraft that humanity has, also carry on board a gold-plated disk that contains images of the Earth and sound recordings (locutions in 56 languages as well as musical fragments). . Voyager 1 reached Jupiter (1979) and Saturn (1980), and then continued its journey out of the solar system. For its part, Voyager 2, in addition to Jupiter and Saturn, visited Uranus (1986) and Neptune (1989). Both spacecraft are still active and sending data to Earth (the most distant, Voyager 1, is more than 24.3 billion kilometers away from our planet).
These initiatives were mainly promoted by the American astrophysicist Carl Sagan, and although the probability that the information sent into space will reach a supposed extraterrestrial civilization and that it can be interpreted is tiny (Sagan himself declared that it was like throwing a bottle into the cosmic ocean with message), have served as inspiration for future missions and as an element of reflection on the possibility that other intelligent beings exist (or have existed) in the universe.
