Solar Wind & Magnetic Fields in Space
Laureate: Eugene N. Parker (posthumous) • Prize awarded 2020, symposium held 2022
About This Prize
The 2020 Crafoord Prize in Astronomy was awarded to Eugene N. Parker(University of Chicago) “for his pioneering and fundamental studies of the solar wind and magnetic fields from stellar to galactic scales.” The symposium was held in April 2022, delayed due to the COVID-19 pandemic. Parker passed away on 15 March 2022, just weeks before the event; his laureate lecture was delivered on his behalf by his long-time colleague Boon Chye Low.
Parker's 1958 prediction that the Sun emits a continuous supersonic stream of charged particles — the solar wind — was initially met with skepticism but was spectacularly confirmed by the Mariner 2 spacecraft in 1962. His theoretical work on magnetic field topology, current sheets, and coronal heating remains foundational to heliophysics and astrophysics. NASA's Parker Solar Probe, launched in 2018, is the first spacecraft named after a living person.
★ Laureate Lecture
Eugene N. Parker (presented by Boon Chye Low)
National Centre for Atmospheric Research, Colorado, USA (on behalf of the late laureate)
“Spontaneous Current Sheets in Solar and Stellar Coronae”
Parker's theory of spontaneous tangential discontinuities (current sheets) in the solar corona, arising from the topological complexity of magnetic field lines anchored in the convecting photosphere. These current sheets are central to the coronal heating problem and nanoflare theory.
◆ Invited Lectures
Milan Maksimovic
CNRS & LESIA, Paris Observatory, France
“Which Theoretical Approach to Better Explain the Solar Wind Expansion: Fluid or Kinetic?”
Maksimovic compares fluid (MHD) and kinetic approaches to modeling solar wind acceleration, discussing how non-Maxwellian electron velocity distributions and kinetic effects shape the fast and slow wind.
Moira Jardine
School of Physics & Astronomy, University of St Andrews, UK
“Stellar Magnetic Fields”
Jardine surveys magnetic field observations across the stellar zoo — from solar-type stars to M dwarfs and young T Tauri stars — using Zeeman-Doppler imaging to reconstruct surface field topologies and their implications for stellar winds and habitability.
Nicola Fox
Science Mission Directorate, NASA Headquarters, Washington, DC, USA
“The Challenge of Exploring Our Sun: The 60-Year Odyssey to Parker Solar Probe”
Fox recounts the six-decade journey from Parker's 1958 prediction to the launch and early discoveries of the Parker Solar Probe — the fastest human-made object, diving into the solar corona to make in-situ measurements of the solar wind at its source.
Rainer Beck
Max-Planck-Institut für Radioastronomie, Bonn, Germany
“Magnetic Fields in Nearby Galaxies and the Milky Way”
Beck presents radio observations of synchrotron emission and Faraday rotation revealing the large-scale ordered magnetic fields in spiral galaxies, their origin through the galactic dynamo, and their role in structuring the interstellar medium.
Ellen Zweibel
University of Wisconsin-Madison, USA
“Cosmic Rays in Galaxies: From Microscales to Macroscales”
Zweibel examines how cosmic rays interact with galactic magnetic fields across scales — from microscopic plasma physics (wave-particle interactions, streaming instabilities) to macroscopic effects on galactic winds, star formation, and galaxy evolution.
Pontus C. Brandt
The Johns Hopkins University Applied Physics Laboratory, USA
“Exploring the Heliospheric Boundary and Beyond: From Voyager to Interstellar Probe”
Brandt discusses Voyager 1 & 2's crossings of the heliopause into interstellar space and the proposed Interstellar Probe mission, which would provide the first external view of our heliosphere and sample the pristine interstellar medium.
Key Concepts
- • Solar Wind: The continuous supersonic outflow of charged particles (mainly protons and electrons) from the Sun's corona, first predicted by Parker in 1958
- • Parker Spiral: The spiral pattern of the interplanetary magnetic field, arising from the combination of radial solar wind flow and solar rotation
- • Coronal Heating Problem: The unexplained heating of the solar corona to millions of kelvin, far hotter than the photosphere — current sheet dissipation and nanoflares are leading candidates
- • Magnetohydrodynamics (MHD): The fluid description of electrically conducting plasmas in magnetic fields, fundamental to modeling solar wind, stellar magnetism, and galactic dynamics
- • Galactic Dynamo: The amplification and maintenance of large-scale magnetic fields in galaxies through the combined action of differential rotation and turbulent convection
- • Cosmic Rays: High-energy charged particles accelerated by supernova shocks and other astrophysical sources, confined and scattered by galactic magnetic fields
- • Heliopause: The boundary where the solar wind pressure balances the interstellar medium, crossed by Voyager 1 (2012) and Voyager 2 (2018) at ~120 AU from the Sun
- • Parker Solar Probe: NASA mission launched 2018, making the closest-ever approaches to the Sun (<10 solar radii) to directly sample the young solar wind and coronal magnetic field