Remarkably, a paper presented to the Royal Society in December 1797 by the then King's Astronomer, Sir William Herschel, (who had discovered Uranus in 1781), includes a description of a possible ring around the planet. Dr Eves believes this is the first observation of the rings that were not seen again for almost two hundred years.
Even Herschel was unable to confirm his possible sightings, and they were not repeated by several generations of astronomers who came after him. (Prior to 1977, when astronomers thought that Uranus lacked rings, Herschel’s claims were dismissed as “clearly erroneous”. And even after 1977, when the existence of the rings was finally established, it was suggested that the rings were far too dim to have been detected by Herschel’s telescopes, and so his claim to priority was ignored).
However, a recent re-evaluation of Herschel’s 1797 paper by Dr Stuart Eves of Surrey Satellite Technology Limited, suggests that Herschel’s claim to have seen one of the rings may well have been correct.
“Herschel got a lot of things right”, notes Dr Eves, “He has a ring of roughly the correct size relative to the planet, and he also has the orientation of this ring in the right direction. In addition, he accurately describes the way the appearance of the ring changes as Uranus moves around the Sun, and he even gets its colour right. Uranus’s Epsilon ring is somewhat red in colour, a fact only recently confirmed by the Keck telescope, and Herschel mentions this in his paper.”
But if Herschel could see the Epsilon ring in the late 1700’s, why did no-one else follow up his observations in subsequent years as the telescopes astronomers used improved? “There are several mechanisms that could account for this”, suggests Dr Eves, “The current Cassini satellite mission to Saturn is telling us that its rings are becoming darker and also expanding, (becoming more diffuse), over time. If these same mechanisms are also operating at Uranus, then the appearance of its rings could have changed quite markedly over 200 years, making them much harder to detect.” Herschel’s observations could thus be proof that planetary ring systems in our solar system are far more dynamic than has previously been supposed.
Tracing aromatic molecules in the early universe
23.03.2017 | University of California - Riverside
New study maps space dust in 3-D
23.03.2017 | DOE/Lawrence Berkeley National Laboratory
Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.
The results will be published on March 22 in the journal „Astronomy & Astrophysics“.
Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...
Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.
Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...
In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...
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