A new solar cycle comes roughly every 11 years. Over the course of each cycle, the Sun transitions from relatively calm to active and stormy, and then quiet again; at its peak, the Sun’s magnetic poles flip. Now that the star has passed solar minimum, scientists expect the Sun will grow increasingly active in the months and years to come.
Understanding the Sun’s behavior is an important part of life in our solar system. The Sun’s outbursts—including eruptions known as solar flares and coronal mass ejections—can disturb the satellites and communications signals traveling around Earth, or one day, Artemis astronauts exploring distant worlds. Scientists study the solar cycle so we can better predict solar activity. As of 2020, the Sun has begun to shake off the sleep of minimum, which occurred in December 2019, and Solar Cycle 25 is underway. Scientists use several indicators to track solar cycle progress.
Sunspot number over the past five solar cycles. Scientists use sunspots to track solar cycle progress; the dark spots are associated with solar activity, often as the origins for giant explosions — such as solar flares or coronal mass ejections — which can spew light, energy, and solar material out into space.
GCMD keywords can be found on the Internet with the following citation:
Olsen, L.M., G. Major, K. Shein, J. Scialdone, S. Ritz, T. Stevens, M. Morahan, A. Aleman, R. Vogel, S. Leicester, H. Weir, M. Meaux, S. Grebas, C.Solomon, M. Holland, T. Northcutt, R. A. Restrepo, R. Bilodeau, 2013. NASA/Global Change Master Directory (GCMD) Earth Science Keywords. Version 220.127.116.11.0