When looking for life outside Earth, scientists mention Mars, Saturn and its moons and some exoplanets outside the solar system. But we rarely hear about one of the most distant yet attractive planets in the solar system. One that NASA has proposed to ESA (European Space Agency) to visit together this century: Uranus. For the American agency, Uranus would offer “the opportunity to participate in an innovative and emblematic mission”, he noted in an opinion article in Nature.
The authors of the editorial, Olivier Mousis, an astrophysicist at the University of Aix-Marseille, and the American astrophysicist Robin Canup, of the Southwest Research Institute in Boulder, Colorado, point out: “The lack of substantial European participation in a project that such “Once in a lifetime it would also undermine the large community of scientists, engineers and technicians dedicated to space exploration throughout Europe who have a great interest in the planets and the search for extraterrestrial life.”
With these words Mousis and Canup proposed an international partnership with NASA. Cooperation would ensure that the mission to Uranus, which would involve put a robotic spaceship around the planet and launch a probe into its thick, icy atmosphere. The mission will take 10 years to develop and between 12 and 15 years to reach Uranus.
This is not the first time that NASA and ESA have proposed joining forces. In 2004, NASA’s Cassini probe entered orbit around Saturn before launching an ESA-built probe, called Huygens, which then landed by parachute on the planet’s moon Titan.
In their editorial, Mousis and Canup argue that if ESA does not seize the opportunity to join a mission to Uranus, a consortium of individual European countries should be created to build the probe that would be launched from the US-built spacecraft.
But why Uranus? The solar system is made up of three categories of planets: the inner rocky worlds of Mercury, Venus, Earth and Mars; two gas giants, Jupiter and Saturn, which are furthest from the Sun; and then, at the edge of the solar system, Uranus and Neptune. These are known as ice giants because They have a diameter four times that of the Earth and they have large amounts of methane, water and other ice-forming molecules in their atmospheres.
This last feature was always considered intriguing, but not interesting enough to justify sending a probe. At least until other similar planets were studied in other regions of space. And what they discovered was that these ice giants are common throughout our galaxy. “Nature loves to create planets this size” explains Jonathan Fortney, a planetary scientist at the University of California, in an interview.
To this we must add that Uranus is different in some peculiar aspects. While the rest of the planets in our solar system spin like tops, Uranus lies on its side. And although it is not the planet furthest from the Sun, yes it is the coldest in the solar system. As if this were not enough, each pole of the planet spends decades bathed in uninterrupted sunlight, followed by decades of total darkness.
Despite these qualities of great interest to astronomers, only one space probe has visited Uranus and from afar. In 1986, Voyager 2 passed by, revealing a drab, pale blue world with a family of moons, 28 in total. Since then we have never returned. Although interest has not faded.
Two years ago, the United States National Academy of Sciences published a report calling on NASA to launch a probe to Uranus as a priority mission. And this has to do with another reason why experts want to go to Uranus. As happened with the beginnings of the exploration of the planet, daring beyond (Uranus is 20 times farther than the Sun and 34 times farther than Mars), force scientists to develop new technologies that would later have an application on our planet.
