Electric fields induced in the Earth during magnetic storms can drive uncontrolled currents in electric-power systems, interfering with their operation. Geomagnetically induced currents realized during the magnetic storm of March 1989 caused a blackout in Québec, Canada, and, in the Mid-Atlantic and Northeast United States, they caused operational interference for electric-power companies and damaged a high-voltage transformer. In support of projects for estimating geoelectric hazards and improving power-system resilience, maps are made of March 1989 magnetic-storm geoelectric hazards and corresponding impacts on United States power systems. Results are based on modeling geomagnetic monitoring data, geoelectromagnetic survey data, and a compilation of published reports of power-system interference. During the storm, electric-power system interference was concentrated where the lithosphere is relatively electrically resistive, and when and where the geoelectric field was of high amplitude. This was particularly true in the Mid-Atlantic and Northeast, near many of America's largest cities, and in the upper Midwest. Retrospective analyses, such as this one for the March 1989 storm, show where utility companies might concentrate their efforts to mitigate the impacts of future magnetic superstorms.

Space particle radiation is one of the main concerns in planning long-term human space missions. There are two main types of hazardous particle radiation: (a) solar energetic particles (SEP) originating from the Sun and (b) galactic cosmic rays (GCR) that come from the distant galaxies in space. Fluxes in particles of solar origin maximize during solar maximum when particles originating from the distant galaxies are more efficiently deflected from the solar system during times when the sun is active. Our calculations clearly demonstrate that the best time for launching a human space flight to Mars is during the solar maximum, as it is possible to shield from SEP particles. Our simulations show that an increase in shielding creates an increase in secondary radiation produced by the most energetic GCR, which results in a higher dose, introducing a limit to a mission duration. We estimate that a potential mission to Mars should not exceed approximately 4 years. This study shows that while space radiation imposes strict limitations and presents technological difficulties for the human mission to Mars, such a mission is still viable.

The operating satellites in low-Earth orbit give the rapid information transfer between the satellites and the Earth. At the same time, these satellites are continuously slowed down and affected by the dense atmosphere of the Earth, which is referred to as the atmospheric drag. This effect can be greater during space weather events such as geomagnetic storms. Over the past years, thousands of Starlink satellites have been deployed by the SpaceX company into low-Earth orbit. However, on 4th February, 38 Starlink satellites were destroyed before they were lifted to a higher Earth orbit, which brought an economic loss estimated to be several tens of millions of dollars. Geomagnetic indices indicated two successive geomagnetic storms, which could warm the upper atmosphere and increase the atmospheric drag. In this work, we provide a comprehensive review on the process of space weather during this event from the Sun all the way to the terrestrial atmosphere. We have illustrated the solar eruption, solar wind propagation, and atmospheric density enhancement, using both observed data and model simulations. This study calls for more accurate modeling and better understanding of space weather as well as collaborations between industry and space weather community.

In the last decade, machine learning has achieved unforeseen results in industrial applications. In particular, the combination of massive data sets and computing with specialized processors (graphics processing units, or GPUs) can perform as well or better than humans in tasks like image classification and game playing. Space weather is a discipline that lives between academia and industry, given the relevant physical effects on satellites and power grids in a variety of applications, and the field therefore stands to benefit from the advances made in industrial applications. Today, machine learning poses both a challenge and an opportunity for the space weather community. The challenge is that the current data science revolution has not been fully embraced, possibly because space physicists remain skeptical of the gains achievable with machine learning. If the community can master the relevant technical skills, they should be able to appreciate what is possible within a few years time and what is possible within a decade. The clearest opportunity lies in creating space weather forecasting models that can respond in real time and that are built on both physics predictions and on observed data.

The extreme space weather events of early August 1972 had significant impact on the U.S. Navy, which have not been widely reported. These effects, long buried in the Vietnam War archives, add credence to the severity of the storm: a nearly instantaneous, unintended detonation of dozens of sea mines south of Hai Phong, North Vietnam on 4 August 1972. This event occurred near the end of the Vietnam War. The U.S. Navy attributed the dramatic event to magnetic perturbations of solar storms. In researching these events we determined that the widespread electric- and communication-grid disturbances that plagued North America and the disturbances in southeast Asia late on 4 August likely resulted from propagation of major eruptive activity from the Sun to the Earth. The activity fits the description of a Carrington-class storm minus the low-latitude aurora reported in 1859. We provide insight into the solar, geophysical, and military circumstances of this extraordinary situation. In our view this storm deserves a scientific revisit as a grand challenge for the space weather community, as it provides space-age terrestrial observations of what was likely a Carrington-class storm.

Satellites are exposed to a variety of sources of potentially damaging space radiation. One of the most important of these is the population of high-energy electrons that lies trapped by the Earth's magnetic field—the so-called Van Allen belts. During an extreme space weather event, trapped electron fluxes in the Van Allen belts can increase by several orders of magnitude in intensity, leading to an enhanced risk of satellite damage. One example of this damage is degradation in the power-generating capability of satellite solar panels. The threat from space weather in this context has hitherto been associated with solar proton events, that is, bursts of energetic protons that are sporadically emitted from the Sun. However, our analysis shows that enhancements in the Van Allen belt electron population can exceed the solar proton threat, which has implications for the protection of satellites from such phenomena. It is essential that sufficiently robust engineering design measures are put in place, in order to ensure the future reliability of satellite technology, on which our society is increasingly reliant.