The sun is a giant body of gases that are unimaginably hot. The sun’s core is made of hydrogen and helium, and produces energy through nuclear fusion. It would be a good thing if this nuclear fuel in the center of the sun stayed contained, but a new NASA study has raised concern about the state of the sun.

According to a report from CNET, NASA scientists have observed a hole in the sun’s corona roughly 50 times the diameter of the Earth. The hole was photographed by the Solar Dynamics Observatory, which passed in front of the sun on October 10. Despite the fact that coronal holes are not uncommon, this was the largest one seen by researchers to date.

Despite what it sounds like, the corona doesn’t actually keep the sun’s core contained. The layer is relatively much colder than the sun’s core, and exists in the plasma aura that encapsulates the sun.

Holes in the corona appear as the sun comes down from its 11-year activity cycle. The most recent peak in solar activity was in 2014, and sunspots and solar flares are expected to decrease in frequency and intensity by 2019.

In the recently photographed coronal hole, there was a low level of energy and gas in the sun’s outer layer. Solar winds escape through the hole, which can result in geomagnetic storms here on Earth. These winds are also responsible for the auroras produced in the northern and southern latitudes.