People can see different constellations depending on where they are in the world. People use a telescope to study the stars and their constellations. The Southern Cross is the smallest constellation, but it has some of the brightest stars in the sky. A galaxy is a large group of stars, gas and dust in space. The Sun, Earth and stars that you can see without a telescope, belong to the galaxy called the Milky Way.
Stars begin inside a nebula which is a dark cloud of gas and dust.
These clumps of dust spin around and get hotter and hotter. Eventually the dust and gas form a ball that begins to glow. These glowing balls of gas are called stars. Astronomers believe that there are about 200 billion stars in the Milky Way alone, and it would probably take more than 60,000 years to count them all. Stars seem to twinkle, because when people look at them through the Earth's air, which is moving, it blurs the starlight.