A recent solar storm reaching Mars in May has provided valuable insights into the potential radiation risks that future astronauts may face on the red planet, according to NASA. The sun, as it approaches the peak of its 11-year solar cycle known as solar maximum, has been exhibiting increased activity, including X-class flares and coronal mass ejections.

The solar storm caused auroras and a surge of charged particles and radiation on Mars. NASA utilized the numerous orbiters and rovers surrounding the planet to observe and analyze the impacts of the storm firsthand. This data helps researchers better understand the radiation levels that astronauts may encounter in future missions to Mars.

On May 20, the most extreme solar storm occurred after an X12 flare was released from the sun. X-rays, gamma rays, and charged particles were propelled towards Mars. The X-rays and gamma rays reached the planet first, followed by the charged particles within minutes.

NASA's Curiosity rover, currently exploring Gale Crater, captured images of white streaks resembling snow. These streaks were caused by charged particles colliding with Curiosity's cameras. The solar particles were so powerful that they temporarily shut down the star camera on board the Mars Odyssey orbiter, which assists with orientation.

During the storm, Curiosity's Radiation Assessment Detector (RAD) measured the radiation exposure on Mars. It was determined that an astronaut standing next to the rover would have experienced radiation equivalent to 30 chest X-rays. While not lethal, this surge in radiation is the highest recorded by the rover's instrument since it landed on Mars over a decade ago.

Understanding the peak radiation levels on Mars is crucial for scientists to develop appropriate measures to protect future astronauts. Don Hassler, the principal investigator of RAD, suggested that cliffsides or lava tubes could provide additional shielding from such events. However, he warned that in Mars orbit or deep space, the radiation dose would be significantly higher.

Astronomers expect more solar storms in the coming weeks as the active region on the sun continues to erupt. These storms could impact both Earth and Mars, leading to further observations and measurements.

The MAVEN orbiter, designed to study Mars' atmospheric changes over time, witnessed the solar storm from an aerial perspective. The orbiter captured images of auroras dancing in ultraviolet light over the red planet. Unlike the auroras observed on Earth, Mars' auroras are not concentrated at the poles but appear as a "global diffuse aurora" due to the planet's lack of a global magnetic field.

By leveraging data from various Martian missions, scientists were able to monitor the solar storm's progression. Christina Lee, the MAVEN Space Weather Lead, emphasized that this was the largest solar energetic particle event ever witnessed by MAVEN, with multiple waves of particles bombarding Mars in recent weeks.

This recent solar storm has provided valuable knowledge about the potential radiation risks faced by future astronauts on Mars. It underscores the importance of planning and developing effective shielding strategies to ensure the safety of human exploration on the red planet.