The first images from a new mission to study the sun reveal a ubiquitous burbling of miniature solar flares. The discovery may provide clues for how turbulence in the atmosphere of the sun drives the ebb and flow of solar wind, the high-velocity charged particles throughout the solar system that buffet Earth and the other planets.
“We can already see interesting new phenomena,” Daniel Müller, the project scientist for the mission, Solar Orbiter, said in a statement from the European Space Agency, which released the images on Thursday.
The miniature solar flares, which the scientists call campfires, were seen as the spacecraft made its first pass by the sun. It came within 48 million miles of the sun’s surface, which is just a bit more than half of the distance between Earth and the sun.
The campfires are about one-millionth or one-billionth the size of flares that have been observed from Earth. “The sun might look quiet at the first glance,” said David Berghmans of the Royal Observatory of Belgium, principal investigator of an instrument that takes high-resolution images of the lower layers of the sun’s atmosphere, “but when we look in detail, we can see those miniature flares everywhere we look.”
Solar Orbiter is a joint mission between the Europeans and NASA, which paid for the rocket that took the probe to space.
Launched in February, this mission will provide a new perspective of the sun as it completes 22 orbits in 10 years. While most previous solar missions orbited in the ecliptic, or the same plane that the planets travel around the sun, the orbit of Solar Orbiter will tilt upward so that it will have a better view of our star’s North and South Poles.
That change of view could help solve mysteries about the sun’s magnetic fields and how they accelerate those solar wind particles. The data from Solar Orbiter could help explain the sunspot cycle — Why does the cycle last 11 years? Why are some quiet while others roar violently? — and help models to predict solar storms that could disrupt Earth’s power grids and satellites in orbit.
For now, the spacecraft remains in the ecliptic, even as flybys of Earth and Venus allow it to spiral inward. The first round of data, including the closest pictures ever taken of the sun, demonstrates the spacecraft and instruments are working as designed.
“We can also see how our 10 scientific instruments complement each other, providing a holistic picture of the sun and the surrounding environment,” Dr. Müller said.
A flyby of Venus in 2025 will swing Solar Orbiter out of the ecliptic to an angle of 17 degrees. That is enough to get a good glimpse of the polar regions. Additional Venus flybys will increase the angle to 33 degrees.
The spacecraft carries 10 scientific instruments. Some measure what is happening directly around the spacecraft, like the magnetic fields and particles of the solar wind. Others take pictures of what is occurring on the sun.
As the orbiter approaches the sun, three peepholes in the heat shield will open to allow the instruments to collect data. The assorted cameras also have heat-resistant windows (think of them as scientific sunglasses) as protection.
The cameras will look at a range of wavelengths of light, including ultraviolet and X-rays. Some of the cameras break the light into separate wavelengths to identify specific molecules. One instrument, the coronagraph, includes a disk to block out most of the light and only look at what is going on in the sun’s outer atmosphere, or corona, which you can observe during a total solar eclipse.
Solar Orbiter is not the only spacecraft studying our planet’s star. Ten other missions in space also keep an eye on the sun and the solar wind. The most recently launched, in 2018, is NASA’s Parker Solar Probe, which is making closer and closer flybys of the sun as it reaches the fastest speeds ever achieved by a human-built spacecraft. It will fly within four million miles of the sun’s surface, allowing direct measurements of the corona and other solar regions.