New Solar Cycle begins: Here's what it means
A few hours ago, scientists from NASA and the US National Oceanic and Atmospheric Administration (NOAA) announced that the Sun has entered a new Solar Cycle. They described it as the Solar Cycle 25. But the question is, what exactly happens in this cycle and why it is so important for the scientific community? Let's find out.
The Sun, as everyone knows, is a giant ball of electrically-charged hot gas, which keeps moving constantly, generating a powerful magnetic field. This magnetic field flips completely at a gap of every 11 years or so, switching the places of the Sun's North and South Pole. This change every 11 years is called the beginning of a new Solar Cycle.
Solar Cycles are being tracked since 1755 and the latest one to have begun is the 25th such phase, according to a group of international experts co-sponsored by NASA and NOAA. They claimed that the cycle had started in December 2019 itself but because our Sun is so variable, it can take months after the fact to declare this event.
As Solar Cycle progresses, the activity on the Sun's surface, which can include eruptions such as solar flares and coronal mass ejections, is affected. The beginning of the cycle is marked by Solar Minimum, wherein this activity is very low. Then, it continues to increase to reach a Maximum by the middle of the cycle and fades back to the Minimum by its end.
"As we emerge from Solar Minimum and approach Cycle 25's Maximum, it is important to remember solar activity never stops; it changes form as the pendulum swings," says Lika Guhathakurta, a solar scientist at the Heliophysics Division at NASA.
By tracking Solar Cycles, scientists can particularly keep an eye on the period of Solar Maximum, when the activity on the surface is at its peak. This is the time when solar flares erupt and the Sun hurls powerful bursts of energy and material into space, which can have effects on Earth upon reaching close to our planet.
Light solar ejections can cause beautiful auroras but powerful ones can impact radio communications. In some cases, extreme eruptions can even affect power grids, causing major outages, or interfere with Global Positioning Systems, satellites, airlines, rockets, and astronauts in space. Scientists say by tracking Solar Maximum, they can keep an eye out for such potentially dangerous "space weather hazards" and warn in advance.
Throughout a Solar Cycle, the shift from Solar Minimum to Maximum and then back to Minimum is measured by looking for sunspots. These are dark blotches on the Sun that are associated with the origins of giant explosions such as solar flares and coronal mass ejections. If the Sun's activity increases, the number of sunspots increases and vice versa.
The work to track Solar Cycle-based space weather hazards and preparation for them is being done by NASA and NOAA, along with other federal agencies. NOAA's satellites monitor space weather in real-time and offer predictions, while NASA handles research, improves our understanding of space weather and its forecasting models. Their goal is to predict flares and CMEs like meteorologists forecast weather on Earth.