internet resources
Why does Earth have seasons?
It is true that Earth’s orbit is not a perfect circle. It is slightly elongated, so that during part of the year, Earth is closer to the Sun than at other times
scijinks.jpl.nasa.gov//earths-seasons
What's a solstice?
Astronomy has been important to people for thousands of years. The ancient construction known as Stonehenge in England may have been designed, among other purposes, to pay special honor to the solstices and equinoxes
scijinks.jpl.nasa.gov/solstice