The summer solstice happens at the maximum of the earth's tilt toward the sun. As a result, the sun appears at its greatest height on the day of the summer solstice, with a noontime position that varies very little for many days before and after the summer solstice.
The angle of the earth's axis of rotation is called the axial tilt. The average axial tilt over time is 23.4 degrees, but it varies slightly from season to season because of gravitational effects caused by the moon and the planets.
The angle between the equator and the plane of the earth's orbit around the sun is called the obliquity of Earth's orbit. It changes as the earth's rotational axis shifts relative to its orbital plane; this shift occurs because of gravitational effects from other bodies in the solar system. The current value of the obliquity is 1 degree, but in the past it was much more extreme; estimates range from 90 to 120 degrees.
During an extreme axial tilt, we would not be able to see the sunset every day, since there would be times when the sun is below the horizon. During an extreme axial tilt, seasons would not be able to develop, since there would be only two periods per year when the sun is above the horizon: daytime and nighttime. Since humans need sunlight to survive, these are not viable solutions for our planet.
The sun is constantly above the horizon at the North Pole throughout the summer, and it circles the pole once every day. It is highest in the sky at the Summer Solstice, then travels closer to the horizon until it is below the horizon at the Autumn Equinox. It rises again on the Winter Solstice and stays above the horizon all month long until the next Summer Solstice.
During the night of the summer solstice, there are no clouds or other particles in the Earth's atmosphere that would block out the light from the sun. So all the parts of the earth that are facing the sun experience a day with no darkness over 6 hours long, and all parts that are facing away from the sun experience a night with no sunlight over 6 hours long.
The North Pole is surrounded by ice, so it isn't exposed to the direct rays of the sun for more than six hours at a time. However, some areas near the North Pole are exposed for longer periods of time due to wind and water. When this occurs, solar radiation can damage the ice, causing small craters and pits that grow darker over time. This dark surface absorbs more heat from the sun than its white background, so over time the entire patch of ice will begin to melt.
As winter approaches and the sun starts to rise further south, the North Pole begins to freeze again.
Days feel longer in the summer because the sun rises earlier in the morning and sets later at night. The summer solstice is the day when the Earth's North Pole is closest to the sun. For individuals residing in the northern hemisphere, this is the longest day (with the most daylight hours) of the year. For those in the southern hemisphere, it is the shortest day (nights are long). The days start getting shorter after the summer solstice and before the winter solstice.
At the summer solstice, the sun is located directly over the equator, so there is no offset between the hour hand and the minute hand on a clock. Because a full moon occurs at the time as well, many call this the moon's biggest grin.
The winter solstice is the opposite situation: It is the day with the least amount of daylight and the longest night of the year for those living in the northern hemisphere. In terms of distance from the sun, this is also known as the solar minimum. The days start getting longer after the winter solstice and before the spring equinox.
The length of the day at the summer and winter solstices varies only slightly from place to place on Earth. However, due to the tilt of the planet's axis, people in different parts of the world experience different amounts of sunlight during other times of the year as well.
It is also the day when the sun reaches its zenith in the sky. At midsummer, the sun is directly over the equator, which means that it is not obscured by any clouds or other particles. All around the world, people celebrate with festivals and rituals dedicated to the sun.
The winter solstice is the opposite: it is the day when the Earth's north pole is furthest from the sun. For those living in the southern hemisphere, this is the shortest day of the year. The winter solstice occurs on or around December 21st; however, because of the effect of precession, the date varies between 1750 and 1923 AD.
People in the northern hemisphere see more of the sun during the summer than people in the south, which is why we need more sleep during this time of year. In addition, body functions are at their peak (heart rate, blood pressure, metabolism) at mid-summer, so it is best to avoid activities that require a lot of energy until after the holiday season has passed.
In conclusion, the summer solstice is significant because it marks the beginning of summer and the end of spring.