A solar storm simultaneously hit Earth, the moon and Mars – the first time an eruption was measured on three planetary surfaces at once.

An international fleet of spacecraft detected the outburst, finding the particles were energetic enough to soar through Earth’s magnetic field that typically shields our planet from such events.

The solar storm pummeled the moon and Mars due to a lack of magnetic fields, which astronomers fear could be deadly for future human exploration.

Human beings are considering going back to the moon and eventually to Mars within the following decades. 

‘We are still facing one major hurdle, ‘space radiation,’ which is a significant and unavoidable risk for crews’ health, especially for long-term stays at future lunar or Martian stations,’ reads the study by scientists with the University of Science and Technology of China.

‘In particular, sporadic solar energetic particles (SEPs) generated via extreme solar eruptions may enhance the lunar or Martian surface radiation levels to potentially hazardous values.’

The solar storm was detected on October 28, 2021, but the scientists published their findings today.

The event was captured by the European Space Agency’s (ESA) ExoMars Trace Gas Orbiter (TGO), NASA’s Curiosity Mars rover, the China National Space Administration (CNSA) Moon lander, NASA’s Lunar Reconnaissance Orbiter (LRO), and German Aerospace Center’s (DLR) Eu:CROPIS Earth orbiter. 

The team stated that the event was an example of a rare ‘ground-level enhancement,’ which means particles released in the explosion are energetic enough to pass through the magnetic bubble surrounding Earth and protect us from less active solar outbursts.

This was only the 73rd ground-level enhancement since records began in the 1940s, and none have been recorded since – but still, the first time a solar storm has hit three planetary surfaces simultaneously. 

Since the moon and Mars are not protected in a ‘bubble’ like Earth, particles from the sun can interact with the soil to create secondary generation. 

However, Mars has a thin atmosphere that stops most lower-energy solar particles and slows down the highly energetic ones. 

ESA shared in a statement that ‘a radiation dose above 700 milligray – the unit for the absorption of radiation – may induce radiation sickness via destruction of the bone marrow, resulting in symptoms such as infection and internal bleeding.’

If an astronaut receives more than 10 gray, they are extremely unlikely to survive more than two weeks. 

The 2021 solar storm did not release enough radiation to harm astronauts in lunar orbit –  NASA’s Lunar Reconnaissance Orbiter clocked in just 31 milligray.

Scientist Jingnan Guo researched the solar event, said: ‘Our calculations of the past ground level enhancement events show that on average one event every 5.5 years may have exceeded the safe dose level on the moon if no radiation protection had been provided. Understanding these events is crucial for future crewed missions to the surface of the moon.’

The study shows ExoMars measured 9 milligray, 30 times more than the 0.3 milligray detected on the surface by the Curiosity rover.

ESA’s inner Solar System missions, Solar Orbiter, SOHO and BepiColombo, were also caught in the blast, providing even more vantage points to study this solar event.

Marco Pinto, an ESA research fellow working on radiation detectors, said: ‘We live in a golden age of Solar System physics. 

‘Radiation detectors aboard planetary missions such as BepiColombo, on its way to Mercury, and Juice, cruising to Jupiter, add a much-needed coverage to study the acceleration and propagation of solar energetic particles.’

Earth has a new moon – or at least a ‘quasi-moon’, a new study has revealed. 

A quasi-moon is a space rock that circles the Earth, but is gravitationally bound by the sun. 

This quasi-moon, called 2023 FW13, was discovered by experts using the Pan-STARRS telescope at the top of the Haleakala volcano in Hawaii, and is one of a handful of known quasi-moons. 

Experts think the ancient cosmic companion has been in Earth’s vicinity since 100 BC and will keep circling our planet for at least another 1,500 years, until AD 3700. 

Thankfully, neither 2023 FW13 or a similar quasi-moon called 469219 Kamoʻoalewa are thought to pose any danger to people on Earth. 

Quasi-moons, also known as ‘quasi-satellites’, often look like they are orbiting our planet much like our natural satellite the moon (affectionately known as ‘Luna’).

But they are given the prefix ‘quasi’ because they are gravitationally bound to the sun rather than Earth, rather than the other way around as is the case for Luna.

2023 FW13 is different from our moon because it orbits well outside of Earth’s ‘Hill sphere’, the region around a planetary body where its own gravity is the dominant force attracting satellites. 

Earth’s Hill sphere has a radius of 932,000 miles (1.5 million km), while the radius of 2023 FW13 from Earth is quite a bit larger – around 1.6 million miles. 

‘The dimension of the loop – about 0.18 astronomical unit in radius – is so large that Earth plays essentially no role in its motion,’ Alan Harris, senior research scientist at Space Science Institute in Boulder, Colorado, told Sky & Telescope. 

‘[2023 FW13 is] in no way associated with Earth other than by chance.’ 

2023 FW13 was first observed on March 28 by PanSTARRS before its existence was confirmed by several other telescopes. 

After being confirmed, 2023 FW13 was listed by the Minor Planet Center at the International Astronomical Union (IAU). 

Although the size of 2023 FW13 is unconfirmed, asteroid specialist Richard Binzel estimates it to be about 30 to 50 feet in diameter (10 to 15 metres). 

This is just a tiny fraction of the diameter of our moon, which is 2,159 miles (although a moon is classified as such because of its orbital characteristics rather than its size). 

2023 FW13’s orbit around the sun takes almost exactly the same time as Earth – 365.42 days (1.0005 Earth years). 

While it performs a circle of Earth on its orbital journey, this orbit is so elongated that it reaches out halfway to Mars and reaches in halfway to Venus. 

Earth has several known cosmic companions, many of which are quasi-satellites, although as 2023 FW13 demonstrates there are likely many more to be discovered.

Quasi-satellites tend to follow a ‘stable’ path around Earth for more than a few decades before eventually leaving the planet’s orbit.

2023 FW13 is special because it will has been in its quasi-state for centuries and will remain so ‘for many more centuries to come’, said amateur astronomer Tony Dunn. 

An online simulator created by Dunn shows the orbit of 2023 FW13 in relation to the moon, the sun and other planets in the solar system. 

Another famous quasi-satellite known as 469219 Kamoʻoalewa or 2016 HO3 was also discovered by PanSTARRS back in April 2016. 

469219 Kamoʻoalewa, which is up to 330 feet in diameter, will only be in this orbit for around 300 years in the future, according to Renu Malhotra, a University of Arizona expert. 

Malhotra authored a recent study that found 469219 Kamoʻoalewa could be an ancient fragment of our moon. 

Analysis of light reflected from the space rock suggested it’s made from the same material as minerals in lunar rocks from NASA‘s Apollo missions.