There may be no air in space, but there is wind; Solar wind composed of charged particles ejected from the sun. The exact mechanism behind this phenomenon remains unclear, but ESA’s Solar Orbiter spacecraft has now observed previously unknown “tiny” bursts on the Sun’s surface that blast plasma into space.

For decades, the solar wind has been associated with structures called coronal holes, which are dark spots that appear above the Sun’s surface as its magnetic field expands deeper into the Solar System. Plasma can flow along these open magnetic field lines and escape into the solar system, forming the solar wind. So how exactly is this plasma started?

Now perhaps a new answer to this question has emerged. Solar Orbiter has been watching our local star very closely for the past few years, with a mission that includes closely observing the coronal hole in higher resolution than ever before and at extreme ultraviolet wavelengths.

In doing so, Orbiter detected numerous small jets of plasma emanating from the Sun’s corona. “Tiny” here is of course a relative term: each jet was several hundred kilometers long, reaching speeds of about 100 kilometers per second (62 mph), and lasted between 20 and 100 seconds. However, they are very low in energy compared to other solar flares and emit only one-1,000th the energy of the smallest previously known eruptions. However, their very large numbers can make up a significant percentage of the solar wind.

“One of the results here is that this flow is largely non-uniform; the ubiquity of jets suggests that the solar wind from coronal holes may occur as a very discontinuous flow,” said Andrii Zhukov, principal investigator at the Solar Research Institute. Orbiter Observation Campaign.

Further observations will improve our understanding of these tiny jets as well as the nature of the solar wind. This could provide better space weather forecasts for future astronauts and spacecraft. Fortunately, Solar Orbiter will get a better view over the next few years as its orbit changes to get a more direct view of the Sun’s south pole, where the coronal hole is located.

“Some features of these tiny jets are more difficult to measure from the edge, but in a few years we’ll be seeing them from a different perspective from other telescopes or observatories, so this together will be very beneficial,” Daniel said. Müller is an ESA employee, scientist of the Solar Orbiter project. Source