europa has a new sun probe: On Monday morning at 5.03 a.m.European time, the “Solar Orbiter” of the European Space Agency Esa was launched in Cape Canaveral with an Atlas V rocket. With it, European astronomers want to better understand how our solar system works – one of the four major projects in which Esa 2005 structured its “Cosmic Vision” for astronomical research for the years 2015 to 2025. The medium-sized project is intended to provide new insights into how the sun shapes and influences the solar system based on its magnetic field, its solar wind and its recurring eruptions – not only to better understand our own homeland, but also to understand the general physical principles of the To study the interaction between a star and its planets on the most accessible system.
The sun is one of those phenomena that we are more familiar with from our everyday life than almost any other, and on the other hand modern science and technology have provided us with a picture that clearly differs from our perception. So we humans have always experienced the sun as a largely calm and reliable source of energy, but when we point high-resolution telescopes at it, we see a turbulent surface simmering in constant turmoil, characterized by solar flares and particle storms.
The way to such a dynamic picture of our home star took some time. The direct experience of the sun, and with it that of the stars, as an eternal and unchangeable body, manifested itself early in the Aristotelian worldview and for a long time dominated the human view of the sky. Only Tycho Brahe’s observation of a star explosion in 1572 and Willem Blaeu’s discovery of the star P Cygni in 1600, whose strong star wind caused drastic fluctuations in brightness, showed how misleading this static image of the stars is. We know from experience today that this also applies to our sun, although it is a relatively light main series star in the extremely stable and long-lived phase of hydrogen burning: solar activity has some influence on our terrestrial electrical engineering. Navigation systems, radio communications and power networks are at risk when strong solar flares send charged particles towards the earth.
A new look at the sun
However, the phenomenon of the solar wind was only first described with a theoretical model around 60 years ago. In 1958, the American astronomer Eugene Parker investigated the dynamic consequences of the hypothesis put forward by the German astronomer Ludwig Biermann at the time that the sun continuously ejects gas into the interplanetary space at speeds of a few hundred kilometers per second – a claim that results from the observed orientations the tail resulted in comets that always point away from the sun.