Some science questions can be answered because we can carry out an investigation and present our results. An example of a question we can investigate is:
"Which coloured berries do garden birds prefer?"
We can provide different coloured berries and record the number of birds which feed on each berry, or count how many berries of each colour the birds eat.
Because some ideas in science are about very, very tiny particles, or about very, very large objects, we have to gather evidence and make models to show WHAT WE THINK is happening.
We cannot travel to all parts of our solar system, but we know a lot about it because of the EVIDENCE we collect.