NASA said: “Through its lifetime, the Sun naturally goes through changes in energy output.
“Some of these occur over a regular 11-year period of peak – many sunspots – and low activity – fewer sunspots – which are quite predictable.
“But every so often, the Sun becomes quieter, experiencing much fewer sunspots and giving off less energy.
“This is called a ‘Grand Solar Minimum’ and the last time this happened, it coincided with a period called the ‘Little Ice Age’.”
Some scientists have proposed a new Grand Solar Minimum could occur within the next few decades.