MSV-2035 Astronomy Document - Inside Design - FINAL - FINAL

Astronomy & Astrophysics 23 several molecules have been proposed. With the upcoming missions, facilities on the horizon, this may just be round the corner. The field of exoplanetary science is entering a golden era. 2.11 The Sun The Sun is a variable star with its magnetic activity driving its radiative, electromagnetic and particulate variability – which have profound influence on our space environment and atmosphere. Solar magnetic fields are produced in its interior by a magnetohydrodynamic dynamo mechanism and emerge on the surface of the Sun (photosphere) as sunspots. The emergence and evolution of these magnetic fields on the Sun's surface driven by solar surface plasma flows drive the restructuring of the magnetic fields in the Sun's outer atmospheres – the chromosphere, transition region and corona. Processes such as magnetic reconnection and instabilities in the coronal magnetic fields generate highly energetic solar magnetic storms such as solar flares and Coronal Mass Ejections (CMEs), which are accompanied by intense high energy radiation, solar energetic particle events and eruptions of vast amounts of magnetized plasma material. However, the generation of the large- and small-scale solar magnetic fields and their emergence and evolution in the solar atmosphere is still poorly understood. The role of magnetic reconnection, waves and instabilities in the generation of solar storms such as flares and CMEs is another area of intense study using both observations and theoretical models and simulations. The energetics and dynamics that sustains the million degree hot, solar outer atmosphere – the corona is yet another key question that remains to be understood. The variable solar activity controls the space environment of solar system planets. The Sun-Earth system is an excellent domain to understand fundamental plasma physics processes in the Universe. Given its profound impacts on satellite and planetary technologies, understanding solar activity leads to applications and space weather forecasting capabilities which are of direct benefit to humanity. In the context of solar activity and its influence on planet Earth, some key problems are (a) understanding the drivers of solar radiative variability which impacts climate, Figure 2: A depiction of the heliosphere, the connection between the Sun and the planets. MEGA SCIENCE VISION-2035