Sunday, June 20, 2021, is the longest day of the year. In the Northern Hemisphere this day marks the beginning of summer. But what exactly is the summer solstice? The word “solstice” comes from Latin solstitium—from sol (Sun) and stitium (still or stopped). During this live chat we'll discuss the solstice and answer your questions about the Sun.

This program is made possible through the generous support of Boeing.