Päikesekroonist

Päikesekroonist, known scientifically as solar corona, is the outermost layer of the Sun's atmosphere. It extends millions of kilometers into space and is so diffuse that it is typically invisible to the naked eye. The corona becomes visible during a total solar eclipse when the Moon blocks the Sun's bright disk, revealing the faint, pearly white glow of the corona. Its temperature is extremely high, reaching millions of degrees Celsius, which is much hotter than the Sun's visible surface, the photosphere. This high temperature is a puzzle that scientists are still actively researching.

The solar corona is composed of ionized gases, primarily hydrogen and helium, and is dominated by magnetic fields. These magnetic fields play a crucial role in shaping the corona and driving its dynamics. Features within the corona include coronal loops, which are arcs of hot plasma guided by magnetic field lines, and coronal holes, which are areas of lower density and temperature where the Sun's magnetic field lines extend outward into space. These coronal holes are the source of the fast solar wind, a stream of charged particles that travels throughout the solar system.

The study of the corona is vital for understanding space weather, which can affect Earth by disrupting satellite operations, power grids, and communication systems. Missions like the Parker Solar Probe and the Solar Orbiter are designed to get closer to the Sun than ever before, providing unprecedented data about the corona's behavior and helping to unravel its mysteries.