The highly anticipated total eclipse will occur tomorrow, visible, unfortunately, only from North America, an event already defined as the "phenomenon of the year". The Moon, between the Earth and the Sun, will project a cone of shadow on the Earth's surface in a very narrow geographical band, from Mexico to Canada.
The outermost atmosphere of the sun, the solar corona, «could be 5-6 times larger than the diameter of the star itself, due to the concomitance with the period of maximum solar activity», as explained by Roberto Ragazzoni, professor of astrophysics at University of Padua and new president of the National Institute of Astrophysics. Observing the eclipse live or through the numerous live broadcasts available online will be an opportunity not to be missed, also because in Italy we will have to wait another three years to admire a similar show. «The appointment is for August 2, 2027, when a total solar eclipse will be visible above Lampedusa», recalls Ragazzoni.
For this one on Monday 8 April the time to mark for us Italians is 8.17pm - when the phenomenon will be at its peak - with the maximum duration being four minutes and 28 seconds. The overall Timeline starts at 5.42pm and ends at 10.52pm.
A team of NASA experts dealing with predictive science has developed a computational model that produces updated predictions in almost real time , thanks to data relating to the magnetic field of the solar surface (photosphere) collected by the Solar Dynamics Observatory space telescope. The model, developed by NASA's Pleiades supercomputer, will be compared with the images of the eclipse that will be taken on Monday to verify how much we really know about the dynamics that move the electrically charged gas (the so-called plasma) of the corona. Knowing this part of the solar atmosphere is crucial, because it gives rise to wind and solar storms that can affect the Earth, causing spectacular phenomena such as the aurora borealis but also interference with the normal functioning of satellites, GPS, radio communications and electricity grids.
Monday's eclipse will be an important test for current theories, as has already happened for other past eclipses that have marked the history of science. One of the most memorable was that of May 29, 1919, which allowed the general theory of relativity developed by Albert Einstein only a few years earlier to be tested. «By measuring the position of the stars around the lunar disk it was possible to demonstrate that the immense gravity of the Sun bends and distorts the light arriving from more distant stars as predicted by relativity», recalls Ragazzoni. «It was the true consecration of a theory that until then had remained confined to a narrow scientific field and which today is the basis of many everyday technologies such as GPS».
(Unioneonline/D)