KEPLER-186F
Distance
500 500 light-years from Earth.
Dimensions
7,454 kilometres (4,632 miles) in radius.
DR JAMES O’DONOGHUE
Planetary scientist
Question
How many planets are there in the universe, and how many might have life? From Aziz, age 10
Answer
Our solar system contains one star, which we call the Sun, along with eight planets, including Earth. People have known for thousands of years that Earth is not the only planet in our solar system. But it was only in 1992 that scientists first discovered planets orbiting around other stars. These planets are called exoplanets. ‘Exo-’ means ‘outside’ in Greek, and these planets are outside our solar system.
By the year 2000, scientists had discovered 46 exoplanets. By 2010, there were 511. And today there are more than 5,500 confirmed exoplanets!…
