Sep 21, 2020 - Science

Here comes a new solar cycle

A split showing an active Sun on the left and a quiet Sun on the right.

The Sun during solar maximum (left, April 2014) and a quiet Sun during solar minimum (right, Dec. 2019). Photo: NASA/SDO

The next solar cycle has begun and forecasters are predicting that it's going to be a calm one.

Why it matters: Powerful solar flares shot off by our nearest star can damage satellites in space and even impact power grids on Earth.

  • A more calm solar cycle with fewer extreme flares directed toward our planet would be good news for missions to space as well as all of us on Earth.

State of play: Last week, officials from NASA and the National Oceanic and Atmospheric Administration declared that the previous 11-year solar cycle ended in December 2019 when the Sun was at solar minimum — the point in its cycle with the least activity.

  • Now, the star's activity is amping up again, heading toward solar maximum, expected in 2025.
  • Forecasters are predicting this solar cycle will be similar to the last, which was marked by below-average activity, according to NASA.

How it works: Scientists track and predict a solar cycle based, in part, on the number of sunspots — dark, transient blotches on the Sun's face that shoot out flares — that appear on the star at any given time.

  • “We keep a detailed record of the few tiny sunspots that mark the onset and rise of the new cycle,” Frédéric Clette, one of the forecasters, said in a NASA statement. “These are the diminutive heralds of future giant solar fireworks. It is only by tracking the general trend over many months that we can determine the tipping point between two cycles.”
  • Satellites in space also keep a close eye on the Sun, allowing NOAA and NASA to track flares and predict when they might impact our planet.

Yes, but: Just because forecasters are predicting a more calm than usual solar cycle doesn't mean we should get complacent.

  • Even during solar cycles with little activity, the star can still surprise us, by shooting off powerful flares, so experts say governments need to be prepared, with plans in place to protect satellites and people in orbit as well as power grids on the ground.
  • Eventually, scientists hope to understand the Sun more fully, to the point where they might be able to predict space weather from day to day.

Go deeper: Our violent Sun

Go deeper