Solar Cycle 25 began in December 2019, marking the start of a new 11-year solar cycle. We are currently approaching solar maximum, the peak of activity in the cycle.
Progress of the Cycle
Solar Cycle 25 started off slowly, with solar activity increasing gradually. However, activity has been ramping up more quickly than initial predictions indicated. The cycle is now expected to peak between January and October 2024, about 1-2 years earlier than originally forecast. The predicted sunspot number at solar maximum is 137-173, revised upward from the initial prediction of 95-130. This indicates a moderately strong solar maximum.
Causes of Solar Cycles
The 11-year solar cycles are driven by the Sun’s magnetic field, which completely flips polarity from north to south during each cycle. Sunspots, solar flares, and coronal mass ejections (CMEs) are all manifestations of the Sun’s magnetic activity that increase around solar maximum.
Effects on Earth
During solar maximum, more frequent solar storms can disrupt radio communications, damage satellites, affect power grids, and endanger astronauts. The aurora are more visible at higher latitudes during solar maximum due to increased solar activity. Animals that use Earth’s magnetic field to navigate may become disoriented, including whales, birds and insects.
Forecasting and Prediction
Predicting the timing and strength of solar cycles is challenging, as each cycle is slightly different. New forecasting methods that incorporate more real-time solar observations and look at precursors like solar terminators are improving predictions. Better forecasts allow industries and space agencies to take protective measures for satellites and astronauts ahead of solar storms.
Upcoming Missions
New solar missions like the Parker Solar Probe and Solar Orbiter will provide unprecedented close-up observations of the Sun and solar wind. These missions will help us better understand the Sun and improve space weather predictions for future solar cycles.
Here is a summary of the Parker Solar Probe and the Solar Orbiter missions:
Parker Solar Probe
The Parker Solar Probe is a NASA spacecraft launched in 2018 to study the Sun’s outer atmosphere or corona. Its key objectives are:
- Trace how energy and heat move through the solar corona and what accelerates the solar wind.
- Study the mechanisms that accelerate energetic particles like solar energetic particles.
- Better understand the structure and dynamics of the solar magnetic field.
Some key facts:
- It was the first NASA mission named after a living person, astrophysicist Eugene Parker who first proposed the concept of the solar wind.
- It has flown closer to the Sun than any previous spacecraft, as close as 8.86 million miles.
- It has reached record speeds for a human-made object, up to 364,621 mph.
- In 2021, it became the first spacecraft to fly through the Sun’s atmosphere, the corona.
- Its instruments have made discoveries about phenomena like switchbacks in the solar wind and miniature solar flares called “campfires”.
Solar Orbiter
The Solar Orbiter is an ESA-NASA collaboration launched in 2020 to study the Sun and inner heliosphere from close distances and high solar latitudes. Its main science goals are:
- Understand how the Sun creates and controls the heliosphere.
- Determine how solar activity varies with time.
- Link the solar surface to the heliosphere by combining in-situ and remote sensing observations.
Key facts:
- It carries 6 remote sensing instruments to image the Sun and 4 in-situ instruments to measure the solar wind and fields.
- Its closest approach is around 42 million km, inside the orbit of Mercury.
- It will reach heliographic latitudes up to 33 degrees to view the Sun’s poles.
- It has already observed phenomena like coronal streamers, miniature flares, and switchbacks in the solar wind.
Summary
Solar Cycle 25 is progressing faster than initially expected and will likely peak in 2024 with moderately high activity. Improved solar storm forecasting will help mitigate risks during the approaching solar maximum. Exciting new missions will also advance our understanding of the Sun and the solar cycle.
