Here's why:

* Light Gathering Power: This refers to a telescope's ability to collect light from distant objects. More light collected means a brighter image and the ability to see fainter objects.

* Objective Lens/Mirror: This is the primary optical component of a telescope, responsible for gathering and focusing light.

* Size Matters: The larger the diameter of the objective lens or mirror, the more light it can capture. Think of it like a bucket; a larger bucket collects more water.

The relationship is directly proportional:

* Double the diameter: You quadruple the light gathering power.

* Triple the diameter: You increase the light gathering power nine times.

This is why large telescopes are essential for observing faint and distant objects in space.