Increased Solar Activity: A New Phase for Our Sun?

The Sun has shown a noticeable increase in activity over the past seventeen years, reversing a long-term downward trend that has led solar physicists to question whether our star might be entering a new “Grand Minimum” similar to the one last observed in 1830.

History of Solar Activity

Solar activity began to decline in the 1980s, with each 11-year solar cycle experiencing fewer sunspots, flares, and coronal mass ejections. Solar activity reached its lowest point in 2008, marking the start of the 24th solar cycle, which recorded the weakest solar activity in history.

At that time, all indicators suggested that the Sun was heading towards a prolonged period of low activity, according to James Jasinski from NASA’s Jet Propulsion Laboratory, who remarked, “It was a surprise to see this trend change. The Sun is slowly waking up.”

New Changes in Solar Activity

Since 2008, indicators have been rising again, with solar wind speed increasing by 6%, solar wind density rising by 26%, solar wind temperature climbing by 29%, and the strength of the interplanetary magnetic field carried by the solar wind increasing by about 31%. All of this reflects increased magnetic activity on the Sun.

With the rise in solar activity, geomagnetic storms that generate auroras in Earth’s skies are becoming more frequent. Additionally, coronal mass ejections and radiation flares pose a greater risk to satellites, space stations, and astronauts.

The Grand Minimum Phenomenon

Between 1645 and 1715, there was a period known as the Maunder Minimum, during which astronomer Edward Maunder observed the Sun’s 11-year cycle by monitoring changes in the number of sunspots. During this time, the total number of sunspots did not exceed 50, a very low number reflecting the lack of magnetic activity that produces flares and coronal mass ejections.

Interestingly, the Maunder Minimum coincided with a period of extreme cold in the Northern Hemisphere, informally known as the “Little Ice Age.” However, the exact cause of this cold period remains unclear, although volcanic activity is considered a possible explanation.

Scientific and Research Challenges

Despite our good understanding of the Sun’s 11-year magnetic cycle, long-term trends are difficult to predict and remain a major mystery to scientists. Jasinski states, “Long-term trends are less predictable and are something we have yet to fully understand.”

These findings were published on September 8 in The Astrophysical Journal Letters, opening the door to further research to understand the underlying causes of these changes.

Conclusion

Recent studies indicate that the Sun is experiencing a resurgence in activity after a long period of dormancy. Although the exact reasons behind this change are not yet fully understood, this increased activity could have significant impacts on Earth, from heightened geomagnetic storms to challenges faced by satellites and astronauts. Fully understanding these phenomena remains a significant scientific challenge that requires further research and study.