Answer:
The gravity of the Sun keeps the planets in their orbits. They stay in their orbits because there is no other force in the Solar System which can stop them.
Explanation:
A free summary of Freak the Mighty by Rodman Philbrick. A fun and ... Not so fast. Killer Kane ends up being paroled, and he kidnaps Max on Christmas Eve.
Act 1:7-8
He said to them: "It is not for you to know the times or dates the Father has set by his own authority.
But you will receive power when the Holy Spirit comes on you; and you will be my witnesses in Jerusalem, and in all Judea and Samaria, and to the ends of the earth."
So technically he didn't tell them.
Fun facts.
If you find a machine which goes in a speed of 3×10^8 m/sec, you can see the past and future. You can even travel for longer distant objects like stars