Silent, beautiful, always-on, tireless producer of heat and light, although in mid-August little bit of sunshine we have seen (the numerous rainfall spread throughout our area), our star did not go on vacation. Indeed, it has shown signs of great activity, hiding spots. Ever since Galileo discovered the existence of sunspots and noted their continued displacement, sensing the rotation of the sun, astronomers measure the activity of our star based on the number of spots they see. However, to avoid damaging the retina, as perhaps happened to Galileo, it is imperative that the observations are made using appropriate filters to protect both the eyes and the instruments. After an unusually quiet 2009 in which for some 260 days the sun did not present no spot, in 2010 the sun has begun to be more lively, it being (so far) only for 35 days without spots. The month of August has seen an increasing activity with several spots simultaneously present. The August 11, for the first time in many months, we saw five spots. It was time that our star is shaking from the long slumber that has marked the lowest of his eleven-year cycle that is expected to continue growing to reach the peak of activity in 2013. NASA can breathe a sigh of relief this year in orbit the Solar Dynamics Observatory (SDO) just to follow the awakening of the sun (see images), and it was embarrassing that the star had not cooperated. Every 10 seconds SDO tools churn out 8 high resolution images, obtained using different filters to fathom the behavior of the sun at different depths of the photosphere. Basically an image per second, a deluge of data, made public immediately on the site, which enables us to develop moment to moment behavior of the sun. We see that magnetic strings swell and then limp in conjunction spots from which there is most intense waves that shake the sun. The arches also generate spectacular puffs of matter and accelerated particles: they are the Coronal Mass Ejection (CME), which radiate to the solar system and reaching the Earth can produce magnetic storms. The effects range from the sublime to the concern, from beautiful aurora borealis and black-out large parts of the far north, in extreme cases of very energetic events capable of damaging electrical power distribution systems. The same particles can damage the electronics of the instruments in orbit and are one of the biggest potential danger for astronauts during future interplanetary travel. A solar storm in the human body can deposit a radiation dose greater than 5 times what we consider to be lethal. Astronauts on the Space Station are not exposed to these risks because they are protected by the Earth's magnetic field, the same one that protects us all from radiation dangers of our peaceful sun. The CME can not be certain to stop, but the identification those potentially dangerous can take precautions. Although accelerated to high energies, the particles travel at speeds less than that of light and they take hours to cover the sun-Earth distance. E 'then possible to see them well before they strike. Should also be noted that not all CMEs reach the earth. There are rivers of energy that follow curved paths dictated by the interplanetary magnetic field. The European SOHO satellite, along with NASA satellites Stereo A and B, measure the speed of propagation of the CME and estimate if the Earth will be affected. In most cases, everything turns into beautiful auroras.
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