Dr Vasili Dimitrov, whose work will be presented at the European Planetary Science Congress in Potsdam, said, “If Titan runs out of methane and loses its ‘veil’, it will become a completely different type of astrophysical body. Methane drives the chemical reactions in Titan’s atmosphere but, because it’s so highly reactive and therefore short-lived, it must be replenished. We need to find out just how much methane is stored in the primordial reserve in Titan’s interior at a level where it can escape to the surface. To do this, we need to know how efficiently the methane molecules were packed away when the reserve formed.“
The trapped methane can exist only in molecular structures called clathrates, which occur when “host” water molecules form a cage-like structure around a smaller “guest” molecule (in this case methane). The water crystallizes in a cubic system, rather than the hexagonal structure of normal ice, so that the cages are arranged in body-centred cubic packing. However, not all of the cages are occupied. The maximum efficiency in filling the cages is achieved only if conditions are optimal e.g. the structure forms slowly at temperatures close to absolute zero.
Dr Dimitrov said, “The conditions of Titan’s accretion and evolution are poorly understood, so we cannot yet say how many of the cages were filled and how much methane is contained in the reserve. In addition, we need to do some more experiments in the laboratory to find out more about the transfer of materials between layers.”
Beneath Titan’s surface, there is a permafrost crust that sits on a liquid or semi-liquid mixture of ammonia, methane and water. Beneath that, an icy layer surrounds a rocky core. It is unclear whether methane trapped in the icy layer next to the core has any means of escape. Dr Dimitrov said, “At the moment we can work out an upper and lower limit for the packing efficiency, but this doesn’t tell us which side of the critical value Titan’s methane stockpile falls. With more experiments, together with the data supplied by the Cassini-Huygens mission, we should be able to answer the question of whether this fascinating world will keep its veil of mystery.”
Being able to estimate the packing efficiency of methane in clathrates could also have important applications back on Earth. According to some estimates, the overall methane stock in the Earth’s natural clathrates may be four times higher than the oil stock. Thus, methane extracted from clathrates could one day become a major fuel source for the mankind.
Anita Heward | alfa
Neutron star merger directly observed for the first time
17.10.2017 | University of Maryland
Breaking: the first light from two neutron stars merging
17.10.2017 | American Association for the Advancement of Science
University of Maryland researchers contribute to historic detection of gravitational waves and light created by event
On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...
Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.
Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....
Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).
When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...
Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.
How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...
Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.
It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...
17.10.2017 | Event News
10.10.2017 | Event News
10.10.2017 | Event News
17.10.2017 | Life Sciences
17.10.2017 | Life Sciences
17.10.2017 | Earth Sciences