Our place in space: stars, gravity and Matariki

On a clear, dark night away from streetlights you can see a pale, glowing band across the sky. That band is the Milky Way, our home galaxy, seen from the inside.

Stars and galaxies

A star is a huge ball of hot gas that gives out enormous amounts of light and heat. The Sun is a star, and it only looks bigger than the others because it is so much closer. A galaxy is a giant collection of stars, gas and dust. The Milky Way holds billions of stars, and the universe contains trillions of galaxies.

Gravity holds it together

Gravity is a pulling force between any two objects that have mass. The more mass an object has, the stronger its pull. The Sun has so much mass that its gravity keeps all eight planets travelling around it in paths called orbits. Johannes Kepler worked out that these orbits are not perfect circles but slightly stretched ones, called ellipses.

Sun, Earth and Moon

The Moon does not make its own light. Half of it is always lit by the Sun. As the Moon orbits the Earth about once a month, we see different amounts of that lit half. Those are the phases, from new moon to full moon and back.

Matariki

Matariki is a cluster of stars about 444 light years away, also known as the Pleiades. When it rises in the pre-dawn sky in June or July, it signals the Māori New Year and resets the maramataka, the lunar calendar. Many iwi name nine stars in the cluster, and each is linked to a part of the environment or wellbeing, though names and meanings differ between iwi and hapū. Since 2022, Aotearoa has had a public holiday for Matariki.