AMHERST, Mass. – The public is invited to witness sunset and sunrise of the shortest night of the year among the standing stones of the UMass Amherst Sunwheel on Wednesday, June 20 at 7:30 p.m. and Thursday, June 21 at 5 a.m.
The actual moment of the solstice will be 6:07 a.m. on June 21 when the sun’s position relative to the stars reaches its northern extreme. This marks the astronomical start of summer in the Northern Hemisphere and winter in the Southern Hemisphere. On the dates closest to the moment of the solstice, nights are shortest and days are longest in the Northern Hemisphere and the sun rises and sets at its most northerly spots along the horizon, marked by tall standing stones in the Sunwheel.
At the hour-long gatherings, UMass Amherst astronomer Stephen Schneider will discuss the astronomical cause of the solstice. He will explain the seasonal positions of Earth, the sun and moon, and the design of the Sunwheel and other calendar sites at Stonehenge and at Chankillo in Peru. He will also be available to answer other astronomical questions.
While the Sunwheel events mark the northernmost sunset and sunrise of the year, the sun’s northerly position changes so gradually around the solstice that it rises and sets at almost the same position for more than a week. This is the origin of the word solstice, which means “stationary sun.” Sunwheel visitors who stop in on their own will be able to see the sun rising and setting over the summer solstice stones from roughly June 16-26.
If it is clear for the evening session, telescopes will be set up to safely observe the surface of the sun before sunset, and to observe the moon, Venus and Jupiter after sunset. Visitors to the Sunwheel should be prepared for wet footing and mosquitoes.
The UMass Amherst Sunwheel is located south of McGuirk Alumni Stadium, just off Rocky Hill Road about one-quarter mile west of University Drive. Donations are welcome to help with the cost of additional site work and future events. The events will be canceled in the event of heavy rain.