Summer Solstice - 20th June

The summer solstice marks the peak of summer and takes place on the longest day of the year (when the Sun is at its highest in the sky). In Britain and other places north of the equator (the northern hemisphere) this takes place on 20th or 21st June.

After the summer solstice the days get shorter until the winter solstice when they start to get longer again. The summer solstice has been celebrated since ancient times and is still celebrated around the world today.

In depth

The seasons are caused by a tilt of the axis around which the Earth spins. The tilt means that the Sun shines more on different parts of the Earth at different times of the year.

During our summer, the northern part of the Earth is tilted towards the Sun, so that we get more daylight and warmth. At the same time, places in the southern hemisphere like Australia and South America are tilted away from the Sun so they have winter during June, July and August.

The tilt of the Earth means that the Sun never sets at the North and South Poles during their respective summers. At the summer solstice there are many places in the far north where the Sun never sets. These include parts of Norway, Sweden, Finland, Russia, Alaska, Canada, Greenland and Iceland. These places where the Sun stays in the sky for 24-hours on the summer solstice are part of the Arctic Circle - you can find it on a globe or atlas. It's also referred to as the Land of the Midnight Sun.

In Britain we are not so far north, so we still have some night time. But the summer solstice is the day when we have the longest hours of daylight.

The Sun and the Earth

• The summer solstice in the northern hemisphere is the winter solstice in the southern hemisphere. So in Australia, they celebrate the winter solstice in June, and the summer solstice in December.
• Between the summer and winter solstices are the two equinoxes. These take place when the Sun is positioned evenly over the northern and southern hemispheres.
• In the past, people thought that the Sun travelled around the Earth. Nowadays, we know that it is not the Sun's position that changes, but the Earth's.
• In the Arctic Circle around the North Pole, it is always daylight around the time of the summer solstice. There is also an Antarctic circle around the South Pole, but only a few scientists live there.

Celebrating the summer solstice

The solstice was very important to people in the past, especially in the northern hemisphere because without the summer Sun they could not have grown the food they needed to stay alive. The summer solstice was a joyous time because it marked the longest day of sunlight and the crops that were to come. But it was also a time to mark the passing of the Sun, because from the summer solstice until the winter solstice, each day becomes shorter and shorter.

The solstice is marked all over the world. Although there are differences between cultures, there are also some striking similarities. Many different cultures celebrate the solstice with bonfires. And many different places have monuments designed so that during the solstice, they will line up with the Sun.

Stonehenge

In Britain the solstice is famously associated with Stonehenge. Stonehenge was made thousands of years ago, out of huge stones put together in the shape of a circle. When the Sun rises on the day of the summer solstice, it lines up with one of the stones, called the heel stone, and its first rays shine through a stone archway in the centre circle.

Stonehenge first existed 5,000 years ago, which means it existed thousands of years earlier than Ancient Egypt or Ancient Rome. The stones used to build it weigh several tons and had to be carried many miles, in some cases hundreds of miles.

Nowadays, just like in the past, thousands of people celebrate the summer solstice at Stonehenge every year. Stonehenge is a source of awe and mystery for many: although we know Stonehenge must have been very difficult to build, no one knows exactly how or why it was built. Some people think it was used as a kind of calendar. By looking at how the Sun lines up with the stones, you can tell what time of year it is.

Religious celebration

Many people think that Stonehenge was built as a place to worship ancient gods. Some of the people who celebrate the solstice at Stonehenge are known as Pagans. They believe in modern versions of religions that existed thousands of years ago, thousands of years before the birth of Jesus. Pagans are in awe of the incredible strength of the Sun and the divine powers that create life. For some Pagans, the summer solstice marks the marriage of the God and Goddess, whose union is the force that creates the harvest's fruits.

People across Europe have marked the solstice since ancient times with bonfires and celebrations dedicated to different gods. When Europe became mostly Christian the festivals stayed but turned into a celebration of St John the Baptist. To this day, Christians in many parts of the world celebrate St John's Day, which takes place on 24th June. Just like in ancient times, people often light bonfires to mark the occasion.

Is Stonehenge the only monument to the Summer Solstice?

No. Native Americans made a number of monuments that work in a similar way to Stonehenge. In Chaco Canyon, USA, there are some rocks called the three slabs, put there around 1,000 years ago. They are positioned so that during the summer solstice, the Sun shines in a dagger shape onto a spiral on the wall behind them.

Did ancient European civilisations know about it?

The Ancient Romans had a festival for their goddess Vesta at this time of year. Vesta was the Goddess of the hearth - the fire you have in your home - and was symbolised by fire.

Are there any modern solstice-related monuments or festivals?

There is a modern day one in Nebraska, USA, called Carhenge - it is an exact copy of Stonehenge, except it is made out of old cars.