The Sun has exhibited a significant surge in activity since 2008, according to a new NASA study. While solar activity is known to fluctuate in cycles approximately every 11 years, longer-term variations can persist for decades. For instance, from the 1980s up until 2008, solar activity experienced a consistent decline, reaching its lowest recorded levels during that year. Initially, scientists anticipated that the Sun was entering a prolonged phase of reduced activity. However, contrary to expectations, the Sun began to show signs of increased activity, as detailed in the study published in The Astrophysical Journal Letters.
This unexpected trend could potentially lead to a rise in space weather events, including solar storms, solar flares, and coronal mass ejections (CMEs). Jamie Jasinski, the lead author of the study from NASA’s Jet Propulsion Laboratory, remarked, “All signs were pointing to the Sun going into a prolonged phase of low activity. So it was a surprise to see that trend reversed. The Sun is slowly waking up.” This resurgence in solar activity is particularly relevant for understanding its effects on Earth and beyond.
The systematic tracking of solar activity dates back to the early 1600s, when astronomers such as Galileo began documenting sunspots. Sunspots are cooler, darker areas on the Sun’s surface that result from concentrated magnetic field lines. Regions with sunspots are often associated with heightened solar activity, including intense solar flares and CMEs, which release massive bubbles of plasma into space.
Nasa scientists closely monitor these space weather events due to their potential impact on various aspects of life on Earth. These phenomena can affect spacecraft operations, the safety of astronauts, radio communications, GPS systems, and even terrestrial power grids. Understanding space weather is crucial for safeguarding NASA’s Artemis campaign, which aims to explore the Moon and beyond. Accurate predictions of solar activity help mitigate astronauts' exposure to harmful space radiation.
Set to launch no earlier than September 23, NASA’s IMAP (Interstellar Mapping and Acceleration Probe) and the Carruthers Geocorona Observatory missions, alongside NOAA’s SWFO-L1 (Space Weather Follow On-Lagrange 1) mission, are poised to contribute significantly to space weather research. These missions will gather new observations and data that will inform future exploration efforts on the Moon, Mars, and beyond.
Increased solar activity influences the magnetic fields of planets throughout our solar system. The solar wind, a continuous stream of charged particles emitted from the Sun, along with other forms of solar activity, can expand and compress the magnetospheres of planets, including Earth. These magnetospheres act as protective shields against the plasma jets that emanate from the Sun.
Throughout the centuries, researchers have observed that the quietest periods of solar activity occurred during two notable stretches: a three-decade period from 1645 to 1715 and a four-decade span from 1790 to 1830. Jasinski noted, “We don’t really know why the Sun went through a 40-year minimum starting in 1790.” He emphasized that the longer-term trends of solar activity remain unpredictable and are not yet fully understood.
Leading up to 2008, the prevalence of sunspots and solar wind activity had decreased to such an extent that researchers anticipated the onset of a “deep solar minimum.” However, as Jasinski explained, “the trend of declining solar wind ended, and since then plasma and magnetic field parameters have steadily been increasing.” The analysis conducted by Jasinski and his colleagues utilized a vast array of data from numerous NASA missions, prominently featuring data from the ACE (Advanced Composition Explorer) and the Wind mission, both launched in the 1990s. These missions have provided invaluable insights into solar activity and its effects on Earth.
In conclusion, the latest findings on the Sun's increasing activity underscore the importance of ongoing research in heliophysics to better understand the Sun’s influence on our solar system and to prepare for the implications of heightened solar phenomena.
