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thermal image of uranus rings

Astronomers observe warm glow of Uranus’ rings

The rings of the Uranus were first discovered in late 1977. Two large telescopes in the high deserts of Chile have captured surprisingly bright heat images of the planet. The rings can be seen because they reflect a little light in the visible, or optical, and near-infrared frequency range.

The new images were taken by the Atacama Large Millimeter/submillimeter Array (ALMA) and the Very Large Telescope (VLT) for the first time. They measured the temperature of the rings to be 77 Kelvin, the boiling point of liquid nitrogen which is equivalent to 320 degrees below zero Fahrenheit. The study was published in The Astronomical Journal.

The epsilon ring is the brightest and densest ring of Uranus and differs from other known rings within the solar system especially the rings of Saturn. The rings of Saturn are mostly icy, broad as well as bright and vary in size from the size of micron dust to tens of meters as told by Imke de Pater, a UC Berkeley professor of astronomy. The Epsilon ring of Uranus contains golf ball sized and larger rocks only. The rings of Jupiter contain micron-sized particles whereas the rings of Neptune are mostly dust. Uranus has a broadsheet of dust present between the narrow main rings.

A graduate student Edward Molte said that the epsilon ring is weird because the smaller particles are not visible and that something has been sweeping them out. This step can help us to understand the composition of the rings and the source of the material of each ring.

Rings could be former asteroids captured by the gravity of a planet, remnants of moons that crashed into one another and shattered, the remains of moons torn apart when they got too close to Uranus, or debris remaining from the time of formation 4.5 billion years ago.

The rings of Uranus are different from Saturn due to lower albedo in the optical and infrared region and thus they are really dark like charcoal. The rings of Uranus are narrow when compared to Saturn’s rings, the Epsilon ring of Uranus is 20 to 100 kilometers wide however the rings of Saturn are tens of thousands of kilometers wide.

The Voyager 2 which flew by in 1986 noticed a lack of dust-sized particles for the first time but was unable to measure the temperature. A total of 13 rings can be found on Uranus with gaps of dust in between. The VLT and ALMA satellites were designed to explore the temperature structure of the atmosphere of Uranus. The upcoming James Webb Space Telescope will be able to vastly improve spectroscopy of the planet.

gas giant interior

Formation of superionic ice helps to detect internal structure of Neptune and Uranus

The magic of science has just achieved the unachievable – the most bizarre existence of “supersonic hot ice”. It is called as such because of the peculiarity of frozen water that can remain solid even at extremely high temperature.

Extreme temperature and pressure can crush the frozen substance into increasingly odd varieties. Superionic materials are dual beasts that can exist in dual state-partly solid and liquid at the same time. It is highly conductive material that exists at high pressures such as, one and four million times more than that at sea level and temperature half as hot as the surface of the sun. These conditions are fulfilled by exoplanets like Uranus and Neptune.

After a lot of research conducted by scientists, it was found that water ice becomes hundred times more electrically more conductive. But achieving above mentioned extreme conditions was not a cake walk for scientists. The study has been published in the Nature journal. 

Marius Millot, study leader and researcher at the Lawrence Livermore National Laboratory, California remarked that the ice sample which they have observed is at a very high temperature, ranging to thousands of degrees.

Scientists have already known that there are 17 varieties of crystalline ice and they had predicted 30 years back that water can be squeezed to superionic forms through application of extreme pressure.

For that, a set up was made in which a thin layer of water was placed between 2 diamond anvils and then six giant lasers were used to generate shockwaves at pressure up to 1 to 4 million times Earth’s atmospheric pressure and temperature between 1650 and 2760 degree Celsius. But all these could only be maintained for a fraction of a second, so physicists used lasers to blast a tiny piece of iron foil creating a wave of plasma. The X-rays showed unprecedented cubic lattice structure with oxygen at each corner and one at the face.

After these persistent and consistent experiments of scientists, they finally got a hint about the unusual tilting of the magnetic field of Neptune and Uranus. They concluded that Uranus and Neptune should have superionic ice layers that act as our planet mantle and that is responsible for their unusual magnetic field tilting at different angles.

Roberto Car, a physicist at Princeton University remarked that more investigations are needed to prove that ice is superionic, although this experiment is an important step in understanding the variableness of water.

Thus, this bizarre and unprecedented but the most thrilling creation is going to help in unpuzzling the various reasons for the origin, existence and evolution of these exoplanets.