Can solar winds destroy life on earth?

The influence of the solar wind on the earth

Solar flares

Since the sun is not a completely uniform gas ball, but has an extremely turbulent atmosphere, sometimes extreme events occur. For example, huge plasma arcs, so-called flares, are formed, as a result of which the magnetic field configuration on the sun changes locally and the phenomenon of reconnection can occur: Magnetic field lines break up and reconnect - a kind of magnetic short circuit. During this process, considerable amounts of plasma, often from the mass of Mount Everest, are accelerated to extreme speeds of up to 3,000 kilometers per second and thrown into space. Physicists speak of coronal mass ejections here. Both flares and eruptions of matter can be detected with the help of solar telescopes in the visible and ultraviolet spectral range. In addition, strong emissions in the radio and X-ray range can be observed during such events.

The heliosphere

The continuous flow of particles from the sun drifts through the entire solar system and of course also hits the earth. But that's not all: high-energy particles from the rest of the universe also patter on our planet. At first glance, this cosmic radiation may not have anything to do with the sun, but solar activity affects the particles from the galaxy. The solar wind forms a bubble in the interstellar medium, the so-called heliosphere, at the edge of which part of the cosmic radiation is reflected. If the solar wind varies, this barrier and with it the flow of cosmic particle radiation also changes.

The other planets in our solar system show how the solar wind and high-energy particles interact with the celestial bodies. Mercury, for example, which has only a very weak magnetic field and no atmosphere, is an extremely hostile place because particles from the sun hit the surface directly. Venus has an atmosphere but no magnetic field. It is believed that a magnetic field existed in the past. But after this was no longer available, the solar wind removed light atoms from the atmosphere through collisions at particle level - what remained was an extremely hostile atmosphere made of carbon dioxide and sulfuric acid.

The earth, on the other hand, has very good protection against particles from space: it has a strong magnetic field and an atmosphere. The charged particles from the solar wind and cosmic rays are deflected by the magnetic field in such a way that they circle around the earth in a kind of storage ring, known as the Van Allen Belt. In doing so, they deform the earth's magnetic field - the stronger the solar wind, the stronger. These changes in the magnetic field can even be measured on the earth's surface.

The magnetic field lines of our planet enter the earth near the north and south poles. The charged particles move on small spiral paths around magnetic field lines. Along these spiral paths they can virtually follow the magnetic field lines and hit the atmosphere together with the field lines. A stronger particle flow from the sun leads to a larger number of particles that hit the atmosphere at the poles. This bombardment can occasionally also be observed with the naked eyes: If the charged particles ionize the nitrogen in the atmosphere, the well-known polar lights flicker.