The Sun is the dimmest it has been for nearly a century.
There are no sunspots, very few solar flares - and our nearest star is the quietest it has been for a very long time.
The observations are baffling astronomers, who are due to study new pictures of the Sun, taken from space, at the UK National Astronomy Meeting.
The Sun normally undergoes an 11-year cycle of activity. At its peak, it has a tumultuous boiling atmosphere that spits out flares and planet-sized chunks of super-hot gas. This is followed by a calmer period.