On July 15, a solar filament erupted from the Sun’s upper left side, ejecting a powerful blast of plasma and magnetic fields into space. The resulting explosion was so massive that it seared a deep, fiery scar of hot plasma and debris onto the star’s visible surface.

While filament eruptions aren’t uncommon, astronomers had already been watching an unusually large filament—cold, dense ribbons of gas suspended above the Sun’s surface—that they spotted days before the explosion. When the filament inevitably collapsed, they had the Solar Dynamics Observatory at the ready to capture the violent ripple of plasma caused by small instabilities in the Sun’s magnetic field.

The resulting explosion carved a gargantuan “canyon of fire” more than 250,000 miles (400,000 kilometers) long, with a height of at least 12,400 miles (20,000 km), reported Tony Phillips, an astronomer who manages Spaceweather.com, a site that tracks solar activity and other space weather events. “A grand canyon, indeed,” he wrote in a brief update of the event.

One practical reason astronomers monitor filaments is that eruptions can sometimes cause coronal mass ejection events (CMEs), or intense bursts of plasma and magnetic fields. When CMEs reach Earth, they can trigger geomagnetic storms that shock power grids and network systems. For astronauts in space, these storms may expose them to dangerously high levels of radiation, impacting their health.

Fortunately, follow-up observations by the Solar and Heliospheric Observatory and the National Oceanic and Atmospheric Administration confirmed that this CME appears to be headed away from Earth. As to how long the filament’s scar will last on the Sun, we’ll just have to see.