The Sumerians are thought to have formed the first human civilization in world history. They lived in southern Mesopotamia, between the Tigris and Euphrates Rivers in the Middle East. Cradle of Civilization. Many historians think that cities and towns were first formed in Sumer around 5000 BC.
At noon, on March 21 and September 23rd are the vernal and autumnal equinoxes. The sun is directly overhead at the equator at these times. On June 22nd is the summer solstice, in the Northern Hemisphere. The sun is at the 23.5 degrees Northern latitude.
June 12, 2011. Summer arrives in the northern hemisphere on June 21st -- the summer solstice, which is also the longest day of the year. But strangely enough, the solstice does not mark the day that the Sun rises the earliest. In fact, the date of earliest sunrise is about a week before the solstice. And the latest sunset occurs about a week after the solstice. The mismatch occurs for two reasons. First, Earth's orbit around the Sun is not a perfect circle.