Astronomical Explanation of the Summer Solstice

Summer solstice a time to celebration light! This is the day when the Northern Hemisphere of Earth has its greatest tilt toward the sun. This result is longer days and shorter evenings. In the United States, we celebrate the beginning of summer the time of year meant for vacations, fun, and travel.

Astronomically what is happening is far less romantic. The Earth is always in a 23 -degree tilt on its axis. It is spinning much like a gyroscope on this axis, the North Pole always pointing toward the North Star. The Earth is also in an orbital pattern around the sun. The summer solstice is the astronomical expression explaining the position of the sun in relation to the equator. At this summer solstice, the Earth is in a pattern where it is most tilted toward the sun and the Northern Hemisphere receives the greatest exposure. At a distance, this will show the sun is at its farthest point away from the equator. The summer solstice occurs when the sun reaches the Tropic of Cancer – astrologers refer to this as the date that the sun enters’ the sign of Cancer. In our Northern Hemisphere, the sun will appear to be high in the sky during summertime and low on the horizon in the winter. This solstice occurs usually June 19-24 each year. In contrast, the winter solstice is where the Southern Hemisphere receives the greatest exposure while the Northern Hemisphere receives less.

The most common misunderstanding is that Earth’s seasons are caused by variances in distance from the Earth to the Sun. On the contrary, the Earth’s orbit is almost completely circular; however, it is slightly closer to the Sun during winter in the Northern Hemisphere and closer to the Southern Hemisphere in the summer.

Tillett poetically informs us with, “the Ancients discovered and calibrated using remarkable prehistoric observatories such as Stonehenge in the south-west of England, the Sun seems to travel (decline) ever so slightly southward in the ecliptic each day for some six months of the year, beginning in what is now the month of June. The Sun in December then appears to halt for some three days in his journey before commencing the slow dance northward once more for the next six months before halting at the opposite solstice and starting again. We can observe this by noting over time the way that the Sun is either slightly higher or lower in the sky at noon.”

Historically this time of year was the period between planting and harvesting of the crops. It was the growing season-not just for crops but for people and animals as well. This was considered the time for marriage and weddings when the people were in a lull in their working lives. The creatures were giving birth and rearing their young. This was the point with the most light it was warm, productive, and enlightening.

Tillett, R. (n.d.) The Solstices. Retrieved June 14, 2007 from

Astronomical Explanation of the Summer Solstice

The summer solstice, also referred to as the first day of summer and the longest day of the year, occurs in the northern hemisphere on June 21 and in the southern hemisphere six months later. The summer solstice is proceeded by the spring equinox and followed by the autumn equinox. In some cultures the solstices and equinoxes were regarded as the start of their respective seasons however, for other the marked the mid-point. For this reason the summer solstice has also been referred to as midsummer’s day.

Remember when you were little and your mother made you stand up straight? Luckily, our planet doesn’t have to stand straight as it revolves around the sun but instead gets to lean to one side. It is this tilt, about 23.5 degrees off plum, which makes the season’s possible. The tilt varies, as the Earth isn’t just leaning but wobbling as well. Whether it is summer or winter where you live depends on whether the part of the earth you live on is tilted toward or away from the sun. In the northern hemisphere is tilted toward the sun between around March 20 and September 22, and on or about June 21, the earth’s axis is pointed most directly at the sun.

What is the axis, you ask. The earth’s axis is an imaginary line going through the earth from the South Pole and out the North Pole. For viewers north of the equator, the sun appear higher in the sky on the day of June 21st then on any other in the year. It is also the longest day of year, how long depends on how far north you live. If you live in the extreme north, say the Arctic Circle, there will be a few days when the sun doesn’t even bother to go down. The closer you live to the equator the length of day is changed by the solstice.

Many ancient civilizations went to a lot of trouble to calculate when the solstices would occur; marking time by the phases of the moon was easier but not very reliable when trying to predict when to plant crops or how much of winter was left, for that you needed a solar calendar. To ancient people the sun rising later and setting earlier coupled with the advancing cold temperatures was a serious matter and the knowledge of when the days would lengthen was certainly a comfort in their harsh lives.