Solar System
The sun and Moon
The Sun.
The Sun is one out of billions of stars. The Sun is the closest star to Earth. The Sun rotates once every 27 days. The Sun is now a middle-aged star, meaning it is at about the middle of its life. The Sun formed over four and a half billion years ago. You may think the Sun will die soon, but it will keep shining for at least another five billion years.
The Moon
Circumference at Equator: 10,917.0 km
Diameter: 3,475 km
Mass: 73,476,730,924,573,500 million kg (0.0123 x Earth)
Average Distance from Earth: 384,400 km
Length of Orbit: 27.3 Earth days
Surface Temperature: -233 to 123 °C
The Moon is moving approximately 3.8 cm away from our planet every year. It is estimated that it will continue to do so for around 50 billion years. By the time that happens, the Moon will be taking around 47 days to orbit the Earth instead of the current 27.3 days.