The narrow rings of Saturn behave similarly to uranium, which are planning to probe the probe in 2020-2030-ies.
Luminous pale blue, Uranus was remembered as a ghostly planet in pictures taken by the only Voyager 2 spacecraft that visited it. Due to the large distance from Earth, research began only in the late 1990s, when telescopic optics improved. Since then, Uranus has had a low observational priority.
And it is sad for scientists who want to learn more about the rings of Uranus, discovered 40 years ago. Two companies were created to watch the star pass in front of it in 1977. And both were stunned when they discovered rings around the planet. One of the teams did not even see three of the rings, because she was too impressed.
It is hoped that the spacecraft will fly to Uranus or Neptune in the 2020s or 2030s. NASA is conducting a feasibility study. So now everything depends on Cassini, located on the orbit of Saturn since 2004 (Saturn rings resemble uranium).
“Until the discovery of Uranus, we have never seen dense rings,” said Mark Showalter, a planetary astronomer at the SETI Institute (search for extraterrestrial life). “The narrow rings of Saturn behave like uranium, which made it possible to understand their mechanism much better.”
Uranus snapshot 1998 taken by the Hubble Space Telescope. Until technology improved, it was difficult to track the planet from the Voyager 2 fly-over period in 1986.
Cassini in the last year of his epic mission goes deep into the rings of Saturn. It is in the middle of the 20th “ring orbit”, which will improve the review (maneuvers began in November, and reached a peak in April).
“We expect to look at rings, small moons and other structures that have not been seen before,” said Linda Spilker, a Cassini scientist at the NASA Jet Propulsion Laboratory in California. - “The last time we were close at the time of arrival in 2004. Then we saw only the illuminated side. We now have dozens of opportunities to explore the high-resolution structure on both sides. ”
After completing the maneuver with circular orbits, Cassini will dive between the planet and the rings from April to September. Then on September 15, the device will take a suicidal leap into Saturn to protect the icy world from surface contamination.
But before that, Showalter indicates that Cassini will have time to capture the processes taking place on Uranus, although the apparatus is studying another planet. For example, oscillations in the narrow rings of Saturn resemble a similar process on Uranus. But there are still many secrets that only the uranium mission can solve.
For example, on the images from Voyager 2, dust rings surrounding the main ring system are visible. Then, when Uranus reached the equinox (the nearest point in orbit) in 2008, the Keck telescope observations showed the rings in more detail (since they were located edge-on with the Earth, which simplified the observation). It turned out that the dust shifted to 3100 miles. The reason is still poorly understood.
Another question is what role the moons Cordelia and Ophelia play for the outer ring. But now it is difficult to study, because Uranus is in the sky with fewer stars than it was in the 1970-1980s.
Showalter has been busy in the last few years, working on the New Horizons missions that explored Pluto in 2015 and Cassini. But he hopes to tackle Uranus, to learn more about the cyclic system and to prepare if the spacecraft decides to visit the blue world.