Equinoxes and Solstices: What They Mean for Your Sky

The terms equinox and solstice mark the turning points of our year, and they are written across your sky in light and shadow. They happen because Earth is tilted about 23.5 degrees as it orbits the Sun, so different parts of our planet lean toward or away from the light. Once you know what to look for, you can read the seasons straight from the heavens.

What the Equinox and Solstice Actually Mean

An equinox happens twice a year, when the Sun crosses the celestial equator and day and night are nearly equal everywhere on Earth. A solstice is the opposite extreme: the Sun reaches its highest or lowest point in the sky, giving you the longest or shortest day of the year.

Which one brings summer depends on where you live. When the Northern Hemisphere tilts toward the Sun, it enjoys its summer solstice while the Southern Hemisphere has its winter. The two hemispheres always trade seasons.

How They Change What You See

These turning points reshape your nightly view. Around a solstice, the Sun rises and sets at its most extreme points on the horizon, and your nights are either luxuriously long or frustratingly short for stargazing. Longer winter nights are a gift for spotting fainter stars and deep-sky targets.

The Sun also drifts along a path called the ecliptic, slipping through the real zodiac constellations over the year. The constellations visible after dark shift with the seasons too, which is why your sky in one season looks nothing like the next.

Tips for Watching the Seasons Turn

• Note where the Sun sets against a fixed landmark, then watch that point creep along the horizon over weeks.
• Track your shadow at noon. It is shortest near the summer solstice and longest near the winter one.
• Use the long nights around the winter solstice for your best deep-sky views.
• Learn the seasonal star patterns so you can tell roughly what time of year it is just by looking up.

If you are just getting started, a little planning goes a long way. Our guide to what you can see in the sky tonight will help you make the most of whatever season you are in.

Curious how the Sun and stars sit above your own backyard right now? Open the Starly sky map, set your location, and watch the seasons unfold overhead in real time.