The summer solstice occurs when one of the earth's poles has its maximum tilt toward the Sun. The situation is exactly the opposite in the Southern Hemisphere, where the seasons are reversed. At the winter solstice the day is the year’s shortest, and at the summer solstice it is the year’s longest. The term solstice also is used in reference to either of the two points of greatest deviation of the ecliptic (the Sun’s apparent annual path) from the celestial equator.
1 of 4: solstice. when do they happen and what causes it?
2 of 4: tilt is the reason for solstice i and it causes climate too
3 of 4: Decoding the ancient astronomy of Stonehenge
4 of 4: winter solstice in fairbanks, alaska
Are there
solstices on other
planets?
Yes! All the planets in our solar system rotate on a tilted axis and therefore have seasons, solstices, and equinoxes. Some of these tilts are minor (like Mercury, which is tilted at 2.11 degrees). But others are more like the Earth (23.5 degrees) or are even more extreme (Uranus is tilted 98 degrees!).
Saturn only sees an equinox about once every 15 years (because it takes Saturn 29 years to complete one orbit around the sun).
What is the definition of a solstice, and when do they happen? Is the winter solstice always the first day of winter?
Find out what causes these bi-annual astronomical events, as well as how they bring about the shortest and longest days of the year.
The time-lapase shows the eerie scene in Fairbanks — the sun basically skims the horizon for a brief while and then vanishes.