Stonehenge Solstice

Students drag the sun along the sky, drag a small observer around the circle, or slide the date from day 1 to 365. Buttons jump to the summer solstice, equinox, winter solstice or back to sunrise, and a toggle plays the day. Readouts show the date, sun azimuth and altitude, the direction to the Heel Stone from the observer and the alignment verdict. It shows how the sun's rising point shifts through the year at latitude 51 degrees north, and how prehistoric builders may have marked it.

• Press Summer solstice and Back to sunrise, then check the Alignment readout.
• Drag the observer around the circle until the sun lines up over the Heel Stone.
• Slide the date to the equinox and compare Sun azimuth with the solstice value.
• Press Winter solstice and see where the sun rises compared with midsummer.
• Turn on Play the day and watch the sun's path across the sky.
• Move the date in steps and plot how the sunrise point moves along the horizon.

1. 1Describe how the position of sunrise changes through the year.
2. 2Identify the summer and winter solstices and the equinoxes on a calendar.
3. 3Explain how Stonehenge's main axis points toward midsummer sunrise.
4. 4Use azimuth readings to compare sun positions on different dates.

Questions teachers ask