Make the question small enough to search
If the child asks about space, ask which part they want to know: a planet’s appearance, how a telescope works, or the next launch. These lead to different sources. Browse the contents and index together and look at one relevant section. Avoid choosing the largest encyclopedia simply because it appears comprehensive. The useful book is the one that helps with the question in front of you and gives the child a manageable way into the subject.
Check the kind of information
A description of a historical event and a schedule for a future mission have different freshness needs. Look at the book’s date, author information, and any references it provides. For a current fact that matters, compare it with the relevant organization’s primary information. Explain when you are unsure rather than presenting a confident guess as the book’s answer. You can save the unresolved question for later without making the child wait through an adult research session they did not ask for.
Follow one next question
Ask what the child noticed or still wants to understand after reading the section. They might want to draw a diagram, find a photograph, or stop because the original question is answered. Let that be enough. Do not turn every fact-book visit into a required project. If two sources disagree, note the exact difference and check their dates and scope before deciding why. The activity can model careful curiosity without promising that a single book contains a complete, permanently current account of the topic.