European space scientists were encouraged to join forces Nasa to ensure the success of one of the most ambitious space missions planned for launch this century.
Join a robot space flight to the mysterious planet Uranus would “provide the opportunity to participate in a ground-breaking, flagship-class mission”, astrophysicists said.
The call was made Earththe leading science journal, in a special editorial which encouraged the European Space Agency (Esa) to form an international partnership with Nasa. Such cooperation will ensure that the Uranus mission – which involves placing a robotic spacecraft into orbit around the planet and dropping a probe into its thick, icy atmosphere – is completed on time and on budget.
The mission will take 10 years to develop and 12-15 years to reach Uranus after launch.
The editorial’s authors, Olivier Mousis, professor of astrophysics at Aix-Marseille University, and American astrophysicist Robin Canup, of the Southwest Research Institute in Boulder, Colorado, said: “A lack of substantial European involvement in a perhaps once-in-a-lifetime flagship mission will also undermine the large community of scientists, engineers and technicians involved in space exploration across Europe who have a strong interest in planets and the search for extraterrestrial life.”
The creation of a European-US partnership for a Uranus mission would not be without precedent. In 2004, NASA’s Cassini robotic spacecraft entered orbit around Saturn before releasing an Esa-built probe called Huygens, which then made a parachute landing on the planet’s moon Titan, revealing a world with a crunchy, brittle surface and lakes of liquid hydrocarbons revealed. The joint mission is considered a classic demonstration of the benefits of international spaceflight cooperation.
In their editorial, Mousis and Canup argue that if Esa does not jump at the chance to join a Uranus mission, a consortium of individual European countries should be created to build the probe that will be released from the main spacecraft that built by the USA. Britain, which has a strong record of establishing co-operative ventures in space, would be well placed to play a key role in such a venture.
Scientists argue that Uranus has characteristics that give it special scientific importance. While the rest of the planets in our solar system spin like spindles, Uranus lies on its side. And while it is not the furthest planet from the sun, it is the solar system’s coldest.
Uranus also experiences seasons of incredible length. Each pole spends decades bathed in uninterrupted sunlight followed by decades of total darkness. Yet only one spacecraft has ever visited Uranus: in 1986, Voyager 2 swept by, reveals a featureless pale blue world with a family of moons. There have been no Earth visits since then.
However, this lack of interest is about to change. Two years ago, the US National Academy of Sciences published a report calling on Nasa to launch a Uranus probe as a priority flagship mission. The academy’s views carry enormous influence, and it has put pressure on Nasa to launch a spacecraft to Uranus in the near future.
Two important reasons lie behind the drive to visit Uranus. The first is local. The solar system consists of three categories of planets: the inner rocky worlds of Mercury, Venus, Earth and Mars; two gas giants Jupiter and Saturn, which lie farther from the sun; and then, at the edge of the solar system, Uranus and Neptune. They are known as ice giants because they have diameters four times that of Earth and have large amounts of methane, water and other ice-forming molecules in their atmospheres.
to newsletter promotion
This last feature was always considered intriguing, but not interesting enough to warrant a dedicated probe until astronomers, armed with a series of powerful new telescopes and space probes, began studying planets orbiting other stars.
To their surprise, they found that planets the size of Uranus and Neptune are ubiquitous throughout our galaxy. “Nature loves to make planets this size,” Jonathan Fortney, a planetary scientist at the University of California, Santa Cruz, told the journal. Science.
The question – and the second key reason for the mission – is why? Many theories have been put forward, but until Uranus is studied in detail, no definitive answers will be provided. As well as finding evidence that could explain why ice giants are common around other stars, the mission will also aim to explain why the planet is so cold and its rotation axis is tilted sideways. Mousis and Canup insist, “The scientific drivers for a Uranus mission are compelling.”
