Science & Tech · Space · 13 hrs ago
Solar Orbiter links a solar wind switchback to hot magnetic loops
Solar Orbiter traced a solar wind switchback to its source by measuring particles as the spacecraft passed through it.
The European Space Agency spacecraft crossed the structure on March 2, 2022, about 51 million miles from the Sun.
Switchbacks are sharp bends in the Sun’s magnetic field carried outward by the solar wind, and scientists have debated how they form.
Oxygen and carbon measurements pointed to hot magnetic loops low in the Sun’s atmosphere, where gas had been trapped before escaping.
The findings support a process called interchange reconnection, in which magnetic fields break and reconnect, while the team also saw signs of waves and turbulence.
The particles kept a record of their origin across tens of millions of miles, offering clues about how the solar wind forms.
The results come from one switchback, so how these structures form remains an open question.
Solar Orbiter measurements link a large solar wind switchback to hot magnetic loops near the Sun.
The spacecraft passed through the switchback on March 2, 2022, about 51 million miles from the Sun.
Inside it, oxygen and carbon showed signs of having been heated, while helium fell relative to hydrogen.
The findings support interchange reconnection as a way switchbacks form, while the team also found signs of waves and turbulence.
The study suggests switchbacks can retain a chemical signature of their source across tens of millions of miles.
- Who
- The European Space Agency’s Solar Orbiter and a team led by Jesse Coburn studied the switchback.
- What
- The spacecraft sampled a solar wind switchback whose particles pointed to hot magnetic loops as their source.
- When
- March 2, 2022.
- Where
- About 51 million miles (82 million kilometers) from the Sun.
- Why
- The team investigated how switchbacks form and where their solar wind material originates.
Interchange reconnection
Waves and turbulence
Formation process
Interchange reconnection
A closed magnetic loop reconnects with a field line extending into space, releasing trapped gas.
Waves and turbulence
Waves and turbulence in the solar wind create switchbacks as the wind travels outward.
Evidence in this study
Interchange reconnection
The particle mix was described as a smoking gun for interchange reconnection.
Waves and turbulence
The team also saw signs consistent with waves and turbulence.
Solar Orbiter photographed a switchback from a distance and confirmed its S shape.
Solar Orbiter passed through a large switchback about 51 million miles from the Sun.
The spacecraft recorded five stretches when the magnetic field flipped back toward the Sun.
- Distance from Sun
- About 51 million miles (82 million kilometers)
- Switchback duration
- One stretch lasted about 90 minutes
- Magnetic-field reversals
- Five stretches recorded over six hours
- Hydrogen speed increase
- About 30 miles (50 kilometers) per second inside the switchback
- Study lead
- Jesse Coburn of the Laboratoire de Physique des Plasmas and University College London
What people are saying
Solar Orbiter flew through a very large switchback,
Because of this, we were able to sample rarely observed particles there that have tell-tale fingerprints of their origin.
There are two main competing theories for how a switchback, and by extension the solar wind, forms,
The specific mix of particles detected by Solar Orbiter is the smoking gun for a formation process known as interchange reconnection.