Comets – mysteries of lunar vortices?
Perhaps the riddle of the strange patterns of light material on some areas of the surface of our natural satellite was solved. A cause of them would be the impacts of comets. These are the results of a survey conducted by US researchers Peter Schultz and Megan Bruck Syal.
Clear structures are strange and sinuous stretch for dozens or even thousands of kilometers on the lunar surface. Most of them were on the side of the Moon, but the most popular, named Reiner Gamma training (by his profile similar to the letter of the Greek), can be seen pointing a telescope at the Oceanus Procellarum , the largest basin on the western edge of the visible side of our natural satellite. Reiner Gamma is one of the so-called lunar swirls. Their origin is still debated, but now a new study led by Peter Schultz (Brown University, USA) and Megan Bruck Syal (researcher at the Lawrence Livermore National Laboratory, USA) suggests that many of their peculiarities can be attributed to the impacts of comets on the lunar surface.
Credit: LRO WAC science team
The debate about the nature of these strange configurations seleniche lights in the 70s of last century, when scientists detect small anomalies in the magnetic field of the lunar crust right at the vortex: there the intensity is greater than in other parts. From this discovery, some scientists have proposed the hypothesis that the magnetic shield present in those areas would have protected more effectively by the bombardment of solar wind, while maintaining their appearance so unusually clear and bright.
But Schultz had a different idea about the origin of these vortices, a conviction born from the careful observation of the areas of landing and take-off of the missions of the Apollo program. “You could see that the whole area around the lunar module was smooth and bright and this because of the gas expelled from the engines of spacecraft that had swept the surface,” says Schultz. “These observations have started to make me think that to produce vortices might have been the impacts of comets.” The comets are in fact wrapped in a gaseous atmosphere, which takes the name of crown. Schultz believed that when these bodies will crash on the moon, their foliage can sweep away the outer layers of the lunar dust in the impact, much like the effect produced by gas boosters for the lunar modules. The idea had already been put forward in 1980 by the scientist in the journal Nature.
Now a new study by Schultz and Bruck Syal published in the journal Icarus addressed the issue from a different point of view, which is, trying to simulate the effects of cometary impacts on the Moon and again confirming how this type of phenomena is able to produce effects entirely consistent with the lunar swirls that look. The impact of the comet hypothesis could also explain the presence of magnetic anomalies in the vicinity of the vortices. Simulations have shown that Page impact of comet has sufficient energy to melt some of the tiny dust particles that would hide the surface of the Moon. When the iron-rich melt and then cool, record permanently the presence of the magnetic field at the time of the collision. “Comets carry a magnetic field created by the flow of charged particles that interact with the solar wind,” says Schultz. “When the gas collides with the lunar surface, the magnetic field is amplified and comet ‘stored’ in those small particles in the moment in which they solidify again. In short, everything we see in the simulations of impacts of comets is consistent cones swirls we see on the Moon. We feel that this process provides a plausible explanation, but it may take new lunar missions to definitively resolve the issue. “