It only took a round of photographs of a new solar science spacecraft for scientists to learn something new about the sun.
Solar Orbiter, a joint project of NASA and the European Space Agency (ESA), released in February to give humans a whole new vision of the sun that we see every day of our lives. And it is literally a new sight: the spacecraft is equipped with telescopes and will finish its mission closer to Sun that any probe carrying such instruments has before.
Even with only the first images of the mission, scientists have already identified a surprising new phenomenon they call “bonfires.”
“We have never been closer to the sun with a camera, and this is just the beginning of Solar Orbiter’s long and epic journey,” said Daniel Müller, ESA’s Solar Orbiter project scientist, during a press conference on Thursday ( July 16th )
Related: Solar orbiter: the American-European mission to explore the poles of the sun in photos
After its launch, Solar Orbiter suffered a small hiccup: ESA briefly paused the spacecraft startup process when the coronavirus pandemic limited the agency’s support capacity. But the break didn’t last long before commissioning resumed to prepare the spacecraft’s first loop around the sun.
Between the coronavirus and a few drawbacks to the instrument just before launch, the team had set their expectations for the first low images.
“To be honest, I didn’t dare expect anything,” David Berghmans, a space physicist at the Royal Observatory of Belgium and principal investigator of one of the instruments aboard the Solar Orbiter, said during the press conference.
And it’s that first close-up, or perihelion, that produced the images just released on June 15. The maneuver brought the spacecraft closer to 48 million miles (77 million km) from the sun; that’s about half the distance at which Earth orbits. At the end of the mission, Solar Orbiter will halve that distance again.
But even these first images were full of tantalizing images.
“It’s surprising in the smallest details how many things are happening there,” Berghmans said. “We couldn’t believe it when we first saw this and started giving it crazy names like bonfires and dark fibrils and ghosts and whatever we saw. There are many new small phenomena occurring on the smallest scale.”
Related: The world’s largest solar telescope produces an never-before-seen image of our star
‘Bonfires’ in the sun
Mission scientists are particularly excited because they identified a completely new feature in the images, thanks to its fine details. These structures are small explosions (well, very small relative to the sun, anyway) that researchers have dubbed “bonfires.” According to Berghmans, the smallest bonfires are the size of a European country.
“Campfires are small relatives of the solar flares that we can observe from Earth, millions or billions of times smaller “, Berghmans said in an ESA statement. “The sun may seem calm at first glance, but when we look closely, we can see those miniature flares everywhere.”
While the visible surface of the sun is approximately 99,000 degrees Fahrenheit (55,000 degrees Celsius), the dim crown is a suffocating millions of degrees under any measurement system. That has been a long-standing puzzle for scientists, since logically it should be colder further from the melting furnace within the sun, and it’s one of the puzzles that new missions like Solar Orbiter and NASA do. Parker solar probe they were designed to try to tackle.
The Parker solar probe, by the way, will fly much closer to the sun than the Solar Orbiter, but it does not carry telescopic equipment, only instruments that measure its immediate environment. Solar Orbiter carries both types of instruments.
And Solar Orbiter scientists are confident that these first images are just the beginning of the discoveries the mission will allow.
“You have to remember that the current data we are showing today is simply a by-product of the technical tests we were doing, in these images the instruments are not yet fully configured,” said Berghmans.
Furthermore, the sun is currently at the calmest point of its 11-year activity cycle, so Solar Orbiter should have much more energetic phenomena to study as the mission progresses.
Related: What is inside the sun? A stellar journey from the inside out
More photos of the sun to come
The Solar Orbiter spacecraft, which cost a total of $ 1.5 billion spread across various entities, continues its cruise toward the sun. During the cruise, the local instruments of the spacecraft will work continuously, while the telescopic cameras are switched on and off according to opportunities. Then in November 2021, the science will start in earnest.
First, it will gradually get closer to the sun over the course of a few years, aided by the swings beyond Venus to send it closer to its target. Then in 2025, the spacecraft will leave the main plane of the solar system and begin to follow a tilted orbit that allows it to obtain images of the sun’s poles, which have never been seen in such detail.
But while future images have an even more scientific perspective, there is still something special about the first images of the mission, the scientists said.
“The night we launched, I realized that Solar Orbiter is going to explore distant parts of the solar system and … see the sun from a completely different perspective,” said Müller. “It was really as if the spacecraft had sent us a postcard of its journey.”
Email Meghan Bartels at [email protected] or follow her on Twitter @meghanbartels. Follow us on Twitter @Spacedotcom and on Facebook.
