A solar probe built by the European Space Agency and NASA has delivered the closest photos ever taken of the sun’s surface, revealing a landscape rife with thousands of tiny solar flares that scientists dubbed “campfires” and offering clues about the extreme heat of the outermost part of its atmosphere.
The Solar Orbiter snapped the images using the probe’s Extreme Ultraviolet Imager as it orbited nearly 77 million km from the sun’s surface or roughly halfway between the sun and Earth.
The “campfires” are believed to be tiny explosions, called nanoflares, and could explain why the sun’s outer shield, the corona, is 300 times hotter than the star’s surface.
Scientists typically have relied upon Earth-based telescopes for close-ups of the sun’s surface. But Earth’s atmosphere limits the amount of visible light needed to glean views as intimate as those obtained by the Solar Orbiter.