UMass Amherst Sunwheel and Sky-Watching Events Mark the Summer Solstice on June 21

AMHERST, Mass. – The public is invited to witness sunrise and sunset associated with the summer solstice among the standing stones of the University of Massachusetts Amherst Sunwheel on Sunday, June 21 at 5 a.m. and 7:30 p.m. These Sunwheel events mark the astronomical change of season, when the day is longest and the night is shortest. Heavy rain cancels the events. 

At the hour-long gatherings, UMass Amherst astronomers discuss the astronomical cause of the sun’s solstice, or standstill. This refers to the fact that the sun appears to rise at a fixed spot on the northeast horizon for more than a week, as marked by the tallest stones in the Sunwheel, and to set in a fixed northwest direction.

The exact moment of the solstice is 12:38 p.m. EDT on Sunday, marking the moment when the sun reaches its point farthest north on the celestial sphere. There is very little shift in the sun’s position for about 10 days around this date, so visitors to the Sunwheel can see the sun rising and setting over the tall summer solstice standing stones from about June 16 to 26.

Visitors will hear a presentation on the seasonal positions of Earth, the sun and moon, moon phases, building the Sunwheel and other calendar sites such as Stonehenge, Chankillo and Karnak. UMass Amherst astronomers will also be happy to answer other astronomical questions. If it is clear, they will set up a solar telescope to safely observe the surface of the sun, and there may be an opportunity for a telescopic view of the crescent moon and crescent Venus at the evening session. 

Teachers can earn certificates of participation for attending seasonal gatherings at the Sunwheel. Contact Stephen Schneider ( for more information.

The UMass Amherst Sunwheel is south of McGuirk Alumni Stadium, just off Rocky Hill Road (Amity Street) about one-quarter mile south of University Drive. Visitors to the Sunwheel should be prepared for wet footing and mosquitoes. Donations to help with the cost of additional site work and future events are greatly appreciated.    



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