Photo: RASC-OC

The official start of summer, when the sun sets at its northernmost point on the horizon, is just a few days away, and the public is invited to celebrate at the top of Munson Mountain. 

It's the annual Pen Henge gathering, organized by the Okanagan Centre of the Royal Astronomical Society of Canada, with the assistance of astronomer Chris Purton. 

An array of standing stones atop Munson mark the limits of the Sun's annual traverse across the sky. Every year on the shortest and longest day of the year, participants gather to learn a little solstice astronomy, and watch the sunset cast shadows from the marker stones to the heel stone. 

Purton, a retired radio astronomer at the Dominion Radio Astrophysical Observatory at White Lake, spearheaded the Pen Henge array in 2009. He and other astronomical society members will be on hand to explain its significance and answer questions. 

The free event is open to kids and adults alike, though parking is limited so early arrival is encouraged to avoid needing to park down the road. The gathering officially begins at Friday at 8 p.m., with sunset at approximately 8:50 p.m.