A new discovery by scientists at the Southwest Research Institute (SwRI) is shedding light on how the Sun influences a special kind of space particle known as helium pickup ions.
These particles, which come from outside our solar system, become electrically charged when hit by the Sun’s ultraviolet radiation and then get caught in the magnetic field that stretches across space.
The study, led by Dr. Keiichi Ogasawara and published in The Astrophysical Journal, shows how solar activity—like solar flares and large eruptions called coronal mass ejections (CMEs)—can dramatically affect the speed and behavior of these helium pickup ions.
Unlike the steady stream of solar wind, which flows constantly from the Sun, these ions can reach speeds up to twice as fast, even during calm periods in space.
Using data from NASA’s Solar TErrestrial RElations Observatory, the researchers were able to track how these particles gain energy during solar events.
They focused especially on how the ions interact with interplanetary shocks—sudden changes in solar wind caused by CMEs slamming into slower-moving solar material.
By closely examining these interactions, the team uncovered how pickup ions evolve as they move through different regions of space.
They developed a new method to follow the ions as they pass through shock waves, turbulent areas, and large magnetic structures.
This allowed them to see which events boost their energy, reduce it, or leave it unchanged.
Understanding this process is more than just a scientific curiosity.
These pickup ions are thought to be a key source of solar energetic particles (SEPs), which are high-energy particles that pose serious risks to astronauts and spacecraft. Unlike the solar wind, SEPs can be dangerous because they move much faster and carry more energy, especially during major solar storms.
The study also found that pickup ions behave differently depending on the direction of the magnetic fields they encounter. These subtle differences help scientists trace the complex journey of these particles across space.
By exploring how the Sun accelerates these mysterious particles, the SwRI team is helping to improve our understanding of space weather and its potential hazards.
Their research brings us one step closer to predicting dangerous solar events that could affect future space missions and technology on Earth.
