Get ready to experience radio blackouts and the mesmerizing northern lights (aurora borealis) as a powerful solar storm is making its way to Earth. Sunspot AR3664 is still active after previously producing solar flares which led to the most intense aurora displays in two decades
Against this backdrop, let's study a bit more about solar storms. NASA says that solar storms might have been the key to life. Is it true? Read further.
Around 4 billion years ago, the sun was less bright than it is today, emitting only about three-quarters of its current rays. However, during this early phase, it was far from quiet. The sun's surface was turbulent, marked by massive eruptions that expelled vast amounts of solar material and radiation into space. These powerful solar storms likely played a vital role in warming Earth, compensating for the sun's weakness. Moreover, these eruptions may have provided the energy necessary to transform simple molecules into more complex ones, including RNA and DNA, which are essential building blocks for life. This research was detailed in a study published in Nature Geoscience on May 23, 2016, by a team of NASA scientists.
"Back then, Earth received only about 70 percent of the energy from the sun than it does today,” said Vladimir Airapetian, lead author of the paper and a solar scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “That means Earth should have been an icy ball. Instead, geological evidence says it was a warm globe with liquid water. We call this the Faint Young Sun Paradox. Our new research shows that solar storms could have been central to warming Earth.”
While our sun still produces occasional flares and CMEs, they are less frequent and intense compared to the past. Today, due to the robust Magnetic files of Earth, our planet remains shielded from the effects of such space weather.
However, these solar events can still disrupt Earth's magnetosphere, causing geomagnetic storms that affect radio communications and satellite operations. They also produce auroras, typically seen near the poles where Earth's magnetic field interacts directly with solar particles.
“Our calculations show that you would have regularly seen auroras all the way down in South Carolina,” says Airapetian. “And as the particles from the space weather traveled down the magnetic field lines, they would have slammed into abundant nitrogen molecules in the atmosphere. Changing the atmosphere’s chemistry turns out to have made all the difference for life on Earth.”
During early Earth's history, the atmosphere differed significantly from its present state. Molecular nitrogen, composing 90 percent of the atmosphere then, differed with today's 78 percent. Energetic particles bombarded these nitrogen molecules, breaking them into individual atoms. These nitrogen atoms collided with carbon dioxide, splitting them into carbon monoxide and oxygen.
The free nitrogen and oxygen combined into nitrous oxide, a potent greenhouse gas. Nitrous oxide is about 300 times more effective at warming the atmosphere than carbon dioxide. Calculations by the researchers indicate that if the early atmosphere contained less than one percent nitrous oxide compared to carbon dioxide, it would have sufficiently warmed the planet to support liquid water.
This continual influx of solar particles to early Earth likely not only heated the atmosphere but also provided the energy necessary to form complex chemicals. In a world abundant with simple molecules, the creation of complex molecules like RNA and DNA, which were crucial for the emergence of life, required a substantial amount of incoming energy.
Balancing the energy influx on a growing planet is of vital importance. Excessive energy, however, can be detrimental to our planet. Continuous solar eruptions and particle showers pose a significant risk, potentially stripping a planet's atmosphere if its magnetosphere is weak. This understanding helps scientists assess which types of stars and planets could potentially support life.
