In early May of this year, a solar storm caused auroras to be visible all over the world. These auroras demonstrated the power of solar storms and the radiation they emit. Sometimes, the sun emits “solar particle events”, which are blasts of protons that can have a destructive impact on Earth. These events can cause severe damage to the ozone layer and increase levels of ultraviolet (UV) radiation on the surface of the planet.
A recent study published in July explored what happens during extreme solar particle events and their effects on Earth. Earth’s magnetic field plays a crucial role in protecting life on the planet by deflecting radiation from the sun. However, the magnetic field changes over time, and during periods when it is weak, solar particle events can have a dramatic effect on life across the planet.
Mars, which lost its global magnetic field in the ancient past, experienced a strong solar particle event in May. This event disrupted the operation of the Mars Odyssey spacecraft and increased radiation levels on the surface of Mars significantly. Protons emitted during solar particle events are heavier and carry more energy than electrons, reaching lower altitudes in Earth’s atmosphere and exciting gas molecules.
While hundreds of weak solar particle events occur every solar cycle, extreme events happen roughly every few millennia. These extreme events can deplete ozone levels in the atmosphere, leading to increased UV radiation on the surface and higher rates of solar-induced DNA damage. The study found that if an extreme solar particle event occurred during a period of weak Earth’s magnetic field, the ozone damage could last for six years, significantly impacting life on Earth.
The article also discussed the relationship between Earth’s magnetic field and evolutionary events in the planet’s history. Periods of weak magnetic field have been linked to major evolutionary events, such as the disappearance of Neanderthals and extinctions of marsupial megafauna. The rapid evolution of diverse animal groups during the Cambrian Explosion has also been related to geomagnetism and high UV levels.
The role of solar activity and Earth’s magnetic field in the history of life is still being explored, and research in this area is ongoing. Prof. Cooper specializes in using ancient DNA to study evolutionary processes associated with climate change, human impacts, public health, geomagnetism, and solar physics. His research combines information from various disciplines to study evolution, population genetics, medical science, and conservation.
Understanding the relationship between solar activity, Earth’s magnetic field, and evolutionary events can provide valuable insights into the history of life on Earth and how these factors continue to impact the planet today.
