Solar Orbiter is exploring the inner heliosphere (as close as 0.28 AU) in order to unravel links between activity in the magnetic field-dominated regime of the solar corona and their consequences in the particle-dominated regime of the interplanetary medium. These links are being revealed through analysis of observations of the Sun from a complement of powerful, high-resolution optical instruments, together with those from state-of-the-art instruments which sample, in situ, the properties, dynamics and interactions of plasma, fields and particles in the near-Sun heliosphere. In addition, these plasma and field instruments have high temporal resolutions, and can thus also resolve plasma kinetic processes in the solar wind at intrinsic scales.
Under the overarching question ‘How does the Sun create and control the Heliosphere?’, the Solar and Heliospheric community identified 4 key questions to be addressed using the observations that are being returned by Solar Orbiter:
Q1) How and where do the solar wind plasma and magnetic field originate in the corona?
Q2) How do solar transients drive heliospheric variability?
Q3) How do solar eruptions produce energetic particle radiation that fills the heliosphere?
Q4) How does the solar dynamo work?