1.3k shares, 291 points

Caught in a Solar Storm on the Way to Mars

A chance alignment between Earth and a Mars-bound spacecraft has given us a rare glimpse into the movement of high-energy particles from the Sun.

This image from the Solar and Heliospheric Observatory shows two coronal mass ejections during an event in November 2000.

A accidental alignment of Earth and a spacecraft headed for Mars has allowed us to get a unique look at how high-energy solar particles flow across space. In order to properly plan crewed expeditions to our neighboring planet and beyond, researchers can benefit from the data from this event by better understanding the radiation environment close to Mars.


Illustration of energetic particles being ejected by the Sun.
NASA’s Goddard Space Flight Center Conceptual Image Lab

A wispy sea of charged particles that escape from the Sun’s atmosphere fills the space between the planets in our solar system. Cosmic rays, which flow and ebb against the 11-year cycle of solar activity, are fast protons and atomic nuclei accelerated in harsh settings across the cosmos. High-energy particle bursts from the Sun, which can be released rapidly in powerful solar storms, break up this wavy particle backdrop.

When a spacecraft leaves the magnetic field of Earth, it must travel through this sea of particles and endure solar storms. And if we want to send astronauts to other planets in the future, we’ll need to understand how high-energy solar particles, which are dangerous for both humans and electrical equipment, move across the solar system.


Location of Tianwen-1 (TW-1) relative to Solar Orbiter (SolO), Parker Solar Probe (PSP), and STEREO-A (STA), Earth, and Mars. The black arrow marks the location of the active region that launched the solar storm.
Adapted from Fu et al. 2022

Yongjie Zhang (Chinese Academy of Sciences), Shuai Fu (Macau University of Science and Technology), and Zheyi Ding (China University of Geosciences) led a team that examined the high-energy solar particles created in an event that occurred in November 2020 when the Sun released a solar flare and a massive explosion of solar plasma known as a coronal mass ejection.

A series of unplanned spacecraft alignments along the same solar magnetic field line brought about this incident. Due to this alignment, numerous spacecraft near Earth measured the same burst of energetic particles as the Tianwen-1 spacecraft traveling to Mars, millions of miles away. This provided a unique opportunity to study how energetic particles from the Sun travel through space along magnetic field lines.


Comparison of proton fluence (number of particles collected per unit area) measured by spacecraft at Earth (blue) and by Tianwen-1 at 1.39 au (red). The time increases from (a) to (h). The spectra at Earth and at Tianwen-1 “break” or bend at roughly the same energy, suggesting that there is little evolution as the particles travel outward. 

The scientists discovered that the magnetic field line connecting the satellite did not extend back to the particle’s source by comparing the timing of observations from Tianwen-1 to those from three spacecraft orbiting Earth. This implies that for the particles to reach the spacecraft, magnetic field lines must have been traversed, or they must have dispersed.

The scientists also discovered that when the particles moved from Earth to Tianwen-1’s position at 1.39 au, the shape of the particle energy distribution stayed the same for low, moderate, and high energies. This shows that rather than being determined as the particles move through space, the structure of the energy distribution is defined earlier, when the particles are propelled to high energies.

The solar energetic particle event in November 2020 was the first one that Tianwen-1 saw, but it most certainly won’t be the last. As the solar cycle intensifies, the spacecraft will continue to track high-energy particles from its position in Mars’ orbit, gathering crucial information for comprehending the radiation environment around Mars and preparing for next missions.

Do not forget to share your opinion with us to provide you with the best posts !


subscribe to our top stories

Don't worry, we don't spam

Like it? Share with your friends!

1.3k shares, 291 points

What's Your Reaction?

Dislike Dislike
love love
omg omg
scary scary
wtf wtf


Your email address will not be published.