Research Starters

Most of our known planets have companion satellites called moons. Earth has one moon, while Saturn has the most, with eighteen. Some planets don't have any moons. Which ones are they? Find out how many moons orbit each of the remaining planets. 

The further away a planet is from the sun, the longer it takes to orbit. Earth takes one year, or 365.25 days to orbit the sun. Find out how long it takes the other planets to orbit the sun. 

Stars are formed and live for billions of years. Some then shrink to become hot white dwarf stars that will shine for billions more years. Others become supernovas. Find out more about the life cycle of stars, white dwarf stars, and supernovas. 

The planets near the sun are rocky, while planets further away from the sun are mostly gas. Find out why.