Leaping lambs signal start of spring
These newborn lambs gambolling in the sunlight at the foot of Slemish Mountain in Co Antrim are a sure sign that spring has finally sprung across Northern Ireland.
Also known as the vernal equinox, yesterday marked the moment when the sun crossed the celestial equator from south to north.
The March equinox is associated with rebirth as flowers bloom, animals come out of hibernation and the Christian world prepares to celebrate Easter.
Neither the Earth's north nor south poles were tilted towards the sun, meaning that night and day were almost exactly the same length - 12 hours - across the world.
The Latin word equinox means 'equal night'.
From now until the summer solstice, the days will get longer and the nights will get shorter.
Then, on June 21, the pattern will reverse again as the Northern Hemisphere tilts away from the Sun.