We already know that comets played a significant role in ensuring that conditions were right for life on Earth. Most of the icy, small planetary bodies that otherwise became comets went into forming the gas giant planets in the outer Solar System but some were ejected from the vicinity of the largest planets.
Of these, a fraction ended up in the inner Solar System bringing water and biogenic elements of interest to Earth. Without this cometary transport, life on Earth may never have had a chance to start.
Now, scientists from the Space Research Centre at the University of Leicester have, for the first time, brought samples of the Comet Wild-2 to Diamond. In doing so, using Diamond’s microfocus spectroscopy capabilities – bright and powerful X-rays with a beam size equivalent to one 25th of a human hair – they have discovered that the old model of comets as dusty iceballs is not the whole picture.
Dr John Bridges, from the Space Research Centre, explains the results, ‘Comets are starting to look a lot more complicated than the old dusty iceball idea. For one thing Wild-2 contains material, like chromium oxides, from the hot inner Solar System – so how did that material get mixed in with a comet which has spent most of its life beyond Neptune? It suggests that there has been major mixing of material from inner and outer parts of the Solar System in its earliest stages.
‘At Diamond, we have also been finding X-ray signatures of iron oxides. These are important because they show that on the Wild-2 nucleus there could have been small trickles of water that deposited these minerals. Similar grains are found in carbonaceous chondrite meteorites. This might mean that there have been localised heating events perhaps caused by impact on the Wild-2 nucleus that melted some of its ice.’
Their samples, which were born in the Kuiper Belt near Neptune, were collected by the Stardust space mission, which involved a seven year long, five billion km, journey. They then travelled by more conventional means (Fedex) from the US to the Space Research Centre. The Stardust mission was conceived so that comets could be studied directly as this will help researchers to find out more about the Solar System’s water and the dust that escaped planetary formation.
Dr Bridges adds, ‘It’s now becoming clear that not all comets are the same. For instance, Wild-2 may have more similarities to some asteroids and primitive meteorites than comets from the Oort Cloud, which extends to the outer limits of our Solar System and which are infrequent visitors to Earth.’
Diamond is capable of studying a huge variety of samples from every discipline of scientific research. Dr Fred Mosselmans, Principal Beamline Scientist for Diamond's microfocus spectroscopy beamline, says, ‘In the past year, example of samples studied have included wood chips from the Mary Rose warship, paint pigment samples from Tate Britain, brain tissue to further our understanding of Parkinson's disease, metal on metal hip replacements, stainless steel corrosion and the comet grains from the Stardust mission – a reflection of the huge breadth of research undertaken at Diamond.’
The University of Leicester team plan to study more cometary tracks at Diamond in the months to come, from which they will be able to establish accurate comparisons with meteorites and determine the processes – such as liquid water in the nucleus and mixing in material from the hot inner Solar System – that have gone towards forming comets.
Researchers can contact scientists to discuss their experiment ideas and then put a proposal together for beamtime. An international scientific review panel considers all proposals before allocating time on one of our beamlines. Diamond currently has 11 operating beamlines, with a further 11 being added between now and 2012.
Diamond is supporting the BA Festival of Science which will take place in Liverpool from 6-11 September. The Festival brings over 350 of the UK’s top scientists, engineers and commentators to discuss the latest developments in science with the public. In addition to talks and debates at the University of Liverpool, there will be a host of events happening throughout the city as part of the European Capital of Culture celebrations.
For more information about the BA Festival of Science, including an online programme, visit www.the-ba.net/festivalofscience.
This year’s BA Festival of Science is organised by the BA (British Association for the Advancement of Science) in partnership with the University of Liverpool. It is supported by the Department for Innovation, Universities & Skills, the Liverpool Culture Company and the Northwest Regional Development Agency.
Astronomers find unexpected, dust-obscured star formation in distant galaxy
24.03.2017 | University of Massachusetts at Amherst
Gravitational wave kicks monster black hole out of galactic core
24.03.2017 | NASA/Goddard Space Flight Center
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.
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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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