There are still spirits in heaven

Northern lights - ghosts in the sky

Our sun is a very average star, so to speak, in the "province" of a spiral arm of our galaxy, with a surface temperature of less than 6000 degrees Celsius and a mass of a good 1027 Tons, which corresponds to around 300,000 earth masses. Its diameter is "only" around 1.4 million kilometers, and the moderate luminosity makes our star appear as an inconspicuous point of light to an observer only a few light-years away.

On the other hand, the sun with its radiation is not only the source of our life, but also responsible for almost all energy processes that we enjoy in abundance today. You can keep this in mind: every plant we see uses sunlight. Our heating is fed from an energy store that was built up by the sun, and we drive from A to B with such energy. The sun itself was created from the remains of stars that exploded eons ago - the so-called supernovae, which also contain all the elements that are heavier than lithium. The atoms of our world, like the atoms we are made of, were created in supernovae. Only atomic energy is obtained from processes whose origins can be found in exploding stars. Light as an energy carrier is therefore a prerequisite for our existence.

But the sun radiates more than just light. The enormous momentum of their photons pushes their shell of matter outward into space. Since all atoms lose their electrons from around 3000 degrees Celsius, the sun and its immediate surroundings consist of these two components, free atomic nuclei, protons and electrons; we are talking about a plasma. These particles are largely ejected radially into space, and they typically set off at 1.5 to 3 million kilometers per hour, also towards Earth. On this way they sometimes meet comets and then create a tail that is always directed away from the sun. After about two to four days, the wind reaches the blue planet.

The effects of fast atomic nuclei, protons and electrons are similar to those of radioactive radiation. The alpha radiation consisting of helium nuclei is quite harmless. It is already absorbed by the upper layer of the skin and can cause little damage in the body if it is not absorbed by other means. The situation is different with electrons (beta radiation), which can certainly cause damage to the genetic material by penetrating the layers of the skin. So why can we survive permanent particle bombardment from the sun on earth?

Fortunately, the earth has a permanent magnetic field that extends from the north to the south pole. From physics lessons we remember that charges react to magnetic fields: If a charged particle hits a field, it cannot move in a straight line but is deflected. And this is exactly what happens with the earth. Their magnetic field, which extends far into space, blocks or captures the incoming plasma. With the first US satellite Explorer 1, trapped particles were detected at high altitudes. The region was named the Van Allen Belt after its discoverer.

After all, space travelers within the Van Allen Belt must reckon with a biological equivalent dose of around 50 millisieverts per hour behind three millimeters thick aluminum. After all, that is twice as much as the annual maximum dose for astronauts and for people in Germany, as well as the average dose that the personnel of commercial aircraft will take in around ten years - and with it heavy stuff.