Some objects are invisible in space, but scientists know they exist because of this.
What is radio waves or x-rays?
How are pictures from space sent to Earth?
satellites
Books often show pictures of the planets, but something is wrong. Hint we did this as a scale model.
What is the distance that the planets are apart?
The discovery of non-light emitting celestial bodies were found mainly through this.
What is a telescope?
This is why computers are so important in understanding our solar system.
What is we can collect and analyze data fast enough?
The two forces that hold the planets in their orbits around the sun.
What are gravity and inertia?
Which of these things would we not need on a probe: digital camera, microphone, chemical analyzer, or radio transmitter?
What is a microphone? No one is in it to talk!!
Space travel is difficult for people because of these three things.
What are distance, expense, and danger?
Why do the Hubble Space Telescope and probes give us more information that telescopes on Earth?
Because they are in the atmosphere.