Answer:
Because different telescopes are used to study and observe different types of objects in space.
Step-by-step explanation:
They need many different types of telescopes to look at space because each telescope shows them different things. Light comes in wavelengths from short to long. Even though all light is fundamentally the same thing, the way that astronomers observe light depends on the portion of the spectrum they wish to study. And it also depends on the telescope itself.