BY AMY SAYLE
The temperature in Chapel Hill is 96-but-feels-like-100 as I write this. Astronomically speaking, though, it’s still spring here. Summer arrives to the northern hemisphere at 6:51 a.m. EDT this Saturday.
On that date, June 21, 2014...
1) The Sun reaches its most northern point over Earth’s surface relative to the equator.
2) In the southern hemisphere, it’s the first day of winter -- not summer. So it’s rather northern-centric of us to call June 21st the summer solstice. Instead, we might call it the June solstice.
3) The Sun rises and sets at its most northern points on the horizon relative to the east and west, respectively -- that is, unless you happen to be reading this from north of the Arctic Circle, where the Sun won’t set at all (24 hours of daylight), or from south of the Antarctic Circle, where the Sun won’t rise (24 hours of darkness).
4) It’s the “longest day” (most hours of daylight) in the northern hemisphere (14 hours and 36 minutes in Chapel Hill), but...
5) ...we don’t have our earliest sunrise or latest sunset of the year. In Chapel Hill, we’ve already had our earliest sunrises, at 5:59 a.m. And our latest sunsets, at 8:37 p.m., don’t start happening till later next week. Why don’t the earliest sunrise and latest sunset coincide with the summer solstice? Short answer: Because clock time and Sun time are not the same.
6) The Sun reaches its highest point in our midday sky for the year, but...
7) ...the Sun does not pass directly overhead for us. For that to happen, you'd have to live in the tropics, between the latitudes of 23½° south and 23½° north. Chapel Hill’s latitude is 36° north.
What can you see in the sky this summer? Find out by attending these programs under the planetarium dome:
- Star Families: Summer Skies -- Saturday, July 12, 3:30-4:15 p.m. For families with children ages 7-12.
- Carolina Skies -- every Sunday at 3:30 p.m. through Aug. 24, 2014. For adults and for children ages 8 and older.
To view the real night sky, join Morehead for our free skywatching sessions this summer. If the weather permits, we’ll be at Jordan Lake on June 28, Aug. 2, and Sept. 6, 2014. Also join us in Raleigh at Historic Oak View County Park on Aug. 9, 2014.
Photo credit: The Sun passes higher in the sky in summer than winter. This is roughly how things look from North Carolina. "Sun's path" by US Naval Observatory