When the sun unleashed an extreme solar storm and hit Mars in May, it engulfed the red planet with auroras and an influx of charged particles and radiation, according to NASA.

The sun has been showcasing more activity over the past year as it nears the peak of its 11-year cycle, called solar maximum predicted to occur later this year, reports CNN.

Within recent months, there has been a spike in solar activity, such as X-class flares, the strongest of solar flares, and coronal mass ejections, or large clouds of ionized gas called plasma and magnetic fields that erupt from the sun’s outer atmosphere.

Solar storms that reached Earth in May sparked colorful auroras that danced in the skies over areas that rarely experience them, such as Northern California and Alabama. The storms originated from a massive cluster of sunspots that happened to face Earth. Then, that sunspot cluster rotated in the direction of Earth’s cosmic neighbor: Mars.

Astronomers used the plethora of orbiters encircling the red planet, as well as rovers driving across its surface, to capture the impacts of a solar storm on Mars firsthand — and to understand better what kind of radiation levels the first astronauts on the red planet may experience in the future. The most extreme storm occurred on May 20 after an X12 flare released from the sun, according to data collected by the Solar Orbiter spacecraft currently studying the sun.

The massive flare sent X-rays and gamma rays hurtling toward Mars, and a coronal mass ejection released quickly on the heels of the flare, flinging charged particles in the direction of the red planet.