The Sun is doing something a little bit different, and it's really leaving scientists a bit confused.
The Sun is slowing down, the BBC reported.
"I've been a solar physicist for 30 years, and I've never seen anything quite like this," Richard Harrison, head of space physics at the Rutherford Appleton Laboratory in Oxfordshire, told the BBC.
"If you want to go back to see when the Sun was this inactive... you've got to go back about 100 years," he said.
Some scientists are even hinting the slowdown could be as bad as in the 17th century in a solar time known as the Maunder Minimum, when bitter, freezing cold swept through Europe.
The River Thames froze and there were bitterly cold winters during that time.
"It would feel like the Sun is asleep... a very dormant ball of gas at the centre of our Solar System," University College London's Mullard Space Science Laboratory's Dr Lucy Green said.
"There is a very strong hint that the Sun is acting in the same way now as it did in the run-up to the Maunder Minimum."
But what is particularly unusual about the Sun's low level of activity is that the star is currently at its solar maximum, a point in an 11-year cycle where it's supposed to be at its most active.
The sudden shift has really left scientists stumped.
"It's completely taken me and many other solar scientists by surprise," Dr Green said.