Uranus is one of the most enigmatic bodies in the solar system
University of Wisconsin-Madison/W.W. Keck Observatory–NASA Science. CC BY

The enigmatic Uranus is the next target, chosen as the “star” planet of this next decade by NASA

If we want to unravel the keys to our origins, to the origins of the Earth and of Life, we cannot do so by studying only our planet. Many of these primordial keys are found in other objects, in meteorites, in comets and in planets and moons of our solar system. Just as our ancestors did, we continue to explore our environment, the planetary context in which we emerged and in which we live.

The mission to the ice giant is called UOP (Uranus Orbiter and Probe), will last 19 years and is planned to launch between 2031 and 2038.

NASA’s roadmap for the next 10 years
The Planetary Science and Astrobiology Decadal Survey is the planetary science and astrobiology report produced by NASA and other US government agencies, such as the National Science Foundation. This report identifies the key issues to be addressed in the next ten years and defines the main recommendations to be followed (it is not really binding, although it is usually the main roadmap), prioritizing a series of missions and scientific objectives. .

Obviously, in previous years there were similar reports, but with this system, periodicity and denomination, three major reports have been issued to date: the first, published in 2002, for the decade 2003-2013, the second, in 2011, for the decade 2013-2022, and the last one, on April 19, for the decade 2023-2032.

For their final preparation, these reports are nourished by meetings and panels of experts and the so-called white papers: publications that address issues, objectives, approaches and recommendations from different perspectives.

For 13 years now, I have had the opportunity to participate as co-author or co-signer in some of these white papers. Specifically, in the latter from 2023-2032, I have co-authored white paper #065, Habitability Models for Planetary Sciences, and #349, BIOMARS: A Foundational High Resolution Environmental Sensor Array.

Well, the committee responsible for the report for the next decade identified three major high-level scientific topics: origins, worlds and processes, and life and habitability, and defined 12 major questions. Following the recommendations of the previous Decadal Survey, NASA began studying the concept of a Flagship mission to the so-called Ice Giants. And Uranus was ultimately the planet selected as the winner and top priority in the New Grand Missions.

Mission to Uranus
The UOP (Uranus Orbiter and Probe) is still just a concept and not a mission as such, but it has become the new protagonist in the exploration of the solar system, even putting it before the exploration of Enceladus. The UOP is a mission that will last 19 years and is planned to launch between 2031 and 2038, depending on when it is approved, according to multiple factors: political, economic or even of another nature that could hinder the process.

We know that Voyager 2 passed by Uranus in the mid-1980s (specifically, in 1986) and that no specific mission has been sent there since then. The new space probe would closely examine the planet, its atmosphere, its rings and its moons. The mission would greatly contribute to our still poor understanding of the icy planets.

Although the understanding of the ice giants and their moons has advanced, we still don’t know much about them and I would say, in particular, about Uranus. About this Ice Giant there are more than 3,200 publications collected in the Web of Science database (of which, about 3,000 are articles). However, the existing models about its origin, geology, structure and composition are not clear and are not yet well established.

One of the most enigmatic bodies in the solar system
As highlighted in the report itself, Uranus is one of the most enigmatic bodies in the solar system. It does not really have a true surface (at least in a stable way, as in the terrestrial planets), but rather the planet consists of a set of fluids in continuous circulation, moving and swirling under still unknown patterns.

Its low internal energy, its interesting active dynamics and atmospheric composition (hydrogen, hydrogen sulfide, helium, methane, and traces of water and ammonium), its perhaps “mantle geology” of ice and other compounds (water, ammonium, methane ices ) and its complex magnetic field are aspects that we still do not understand in a planetary puzzle whose pieces are difficult to fit together.

Its moons are considered ocean worlds
It was proposed that a giant impact in its early stages of planetary evolution could be responsible for the extreme axial tilt of Uranus and possibly also for its 13 rings and 27 moons. These, composed of rock and ice, show geological activity and are properly considered oceanic worlds (probably with large masses of liquid water below their crusts).

For all these reasons, Uranus is, for those responsible for the Report, the “star” planet of this next decade in which the UOP will tackle three major main scientific objectives: its origin, interior and atmosphere; the magnetosphere, and the satellites and rings.

Space exploration means that many of the proposals and goals are far-reaching and take years, even decades, to achieve. Specifically, in relation to the outer planets, in 2009 I co-authored the report Technologies for Outer Planet Missions: A Companion to the Outer Planet Assessment Group (OPAG) Strategic Exploration White Paper, for the 2013-2022 Planetary Science and Astrobiology Decadal Survey, which obviously included, among other topics and objectives, the exploration of Uranus.

Therefore, the fact that Uranus is a target selected as a priority for the next decade represents for me not only a scientific satisfaction, but also a personal one. I am convinced that we are going to live a prodigious decade in the exploration of our solar system, in which, in addition to the rover missions currently on Mars, the exploration of some icy moons and Uranus as the main priority, we will witness many other exciting planetary and astrobiological surprises.