Online Seminar with Louise Harra
(PMOD/WRC, Davos & ETH Zurich, Switzerland)
The instruments measure the solar wind as it flows past the spacecraft as well as the sources of the wind across the electromagnetic spectrum. A scientific focus has been on understanding the small-scale jets and brightenings that can feed into the solar wind, as well as the larger scale eruptions now that the solar activity cycle is reaching its peak.
This workshop will focus on the economics and governance of commercialisation in outer space. It will look at the applicability of economic concepts, the concepts of international economic law, and the concepts of economic governance to space-based commerce.
As Earth’s energy source and a variable star, the Sun has been credited over the past century with causing climate change that is a significant fraction of industrial-era warming… or so small as to be undetectable. Now, with more than forty years of space-based observations of solar irradiance and multiple geophysical quantities, and extensive advances in modelling solar irradiance and terrestrial variability, we can clarify with greater certainty the extent to which the Sun alters Earth’s environment, especially since 1850. This talk summarizes current observational evidence for the Sun’s role in global climate change and ozone-depletion recovery, and discusses the scientific (and societal) consequences of faulty detection and attribution.
The magnetic field is fundamental to solar activity and shapes the interplanetary environment, as shown by the full three-dimensional monitoring of the heliosphere provided by measurements from many past and present interplanetary and remote sensing spacecraft. Magnetic fields are also the source for coronal heating and the very existence of the solar wind; produced by the sun’s dynamo and emerging into the corona, magnetic fields become a conduit for waves, act to store energy, and then propel plasma into the Heliosphere in the form of Coronal Mass Ejections (CMEs). Magnetic fields are also at the heart of the generation and acceleration of Solar Energetic Particle (SEPs) that modify the space weather environment of the Earth and other planets.
Parker Solar Probe (PSP)’s launch in 2018, followed by Solar Orbiter (SO)’s launch in February 2020 have opened a new window in the exploration of solar magnetic activity and the origin of the Heliosphere. The first direct measurements of the plasma in the closest atmosphere of our star have already produced significant surprises, including the presence of folds in the magnetic field called switchbacks that come in patches, the prevalence of the bursty phenomenon known as magnetic reconnection together with turbulence in the outer corona and accelerating solar wind.
The observation by NASA’s Parker Solar Probe mission of very strong magnetic field fluctuations in the inner heliosphere, leading to strong deflections locally reversing the direction of the field itself, called switchbacks, has attracted considerable attention from the heliophysics and space physics communities.
Giant planets and brown dwarfs at an orbital separation great than 5 AU are important puzzle pieces needed for constraining the uncertainties that exist in giant planet formation and evolutionary models that are plagued by a lack of observational constraints. In order to observationally probe this mass-separation parameter space, direct imaging is necessary but faces the difficulty of low detection efficiency. To utilize the power of direct imaging, pre-selecting companion candidates with long-period radial velocities, coupled with astrometry from Hipparcos and Gaia, provide a powerful tool to hunt for the most promising candidates for direct imaging. Not only does this increase the detection efficiency, but this wealth of information removes the degeneracy of unknown orbital parameters, leading to derived dynamical masses which can serve as benchmark objects to test models of formation and evolution. With the recently launched JWST, as well as upcoming facilities like the ELT and the Nancy Grace Roman Space Telescope, observing time is valuable and the strategy of direct imaging needs to be re-defined to pre-select targets and characterize the companions that we do discover.
Solar energetic eruptive processes, such as flares and coronal mass ejections, are relatively well-studied during the past decades of direct observations. Although their maximum strength/energy is not constrained by direct data because of a too-short period of observations, we know that extreme events do occur rarely on the Sun over the last millennia, thanks to cosmogenic-proxy data, and also on sun-like stars, thanks to high-precision stellar photometry. Not only we can estimate their occurrence probability but even reconstruct energy spectra and assess the dramatic terrestrial and societal impacts. However, the nature of such events remains unclear – are they ‘normal’ but just extremely strong solar flares (Black Swans) or do they represent an unknown type of solar events (Dragon Kings)? A summary of the existing pieces of knowledge will be presented along with a try to make a distinction between the Black-swan and Dragon-king scenarios of the extreme events.
