Solar ‘campfires’ detected in probe’s close-up images
Fiery loops dubbed ‘‘campfires’’ have been photographed on the Sun for the first time after a British-built spacecraft transmitted the closest-ever images of the star.
The Solar Orbiter probe, a joint venture between the European Space Agency and Nasa, is on a two-year mission to learn more about the nuclear furnace at the heart of our solar system, and the devastating space weather it produces that can wreak havoc on our communications systems.
The first images were taken as the probe made a close pass of 75 million kilometres in midJune, and show looping flares about 800km wide near the surface of the Sun.
The campfires may solve the mystery of why the outermost layer of the Sun’s atmosphere is hotter than the interior – like a fire getting hotter as you move further away.
The solar corona, which extends millions of kilometres into space, is more than a million degrees Celsius, while the surface of the Sun is just 5500C.
Scientists think the campfires may be related to changes in the Sun’s magnetic field as small fields get tangled and stressed, then expand like rubber bands, and eventually tear, releasing energy and heat. These campfires could contribute significantly to heating the solar corona.
Daniel Muller, ESA Solar Orbiter project scientist, said: ‘‘For these campfires to be impacting space weather, they have to be magnetically connected to interplanetary space. There might be areas where they make it into space, and we might be able to identify a link, and nail down the driving mechanism that causes space weather.’’
Dr David Long, a co-principal investigator on the ESA Solar Orbiter Mission extreme ultraviolet imager which captured the images, said: ‘‘No images have been taken of the Sun at such a close distance before, and the level of detail they provide is impressive. They show miniature flares across the surface of the Sun, which look like campfires millions of times smaller than the solar flares that we see from Earth.
‘‘Dotted across the surface, they might play an important role in a mysterious phenomenon called coronal heating, whereby the Sun’s outer layer, or corona, is more than 200-500 times hotter than the layers below.’’
Studying the Sun is critical to plan for disruptive space weather events known as coronal mass ejections, which could wipe out GPS systems, destroy electricity grids, and potentially cause food shortages and continent-wide blackouts.
The biggest recorded geomagnetic storm happened in September 1859, when the Sun flung a colossal wave of electrified gas and subatomic particles at Earth, crippling telegraph systems and showering operators with sparks. A geomagnetic storm left six million Canadians without power in 1989.