Here's why:

* Sensitivity: CCDs are far more sensitive to light than photographic film, allowing astronomers to capture fainter objects and details.

* Linearity: CCDs have a linear response to light, meaning the signal output is directly proportional to the amount of light received. This makes data analysis much easier and more accurate.

* Digital Data: CCDs produce digital data, which can be easily stored, manipulated, and analyzed using computers.

* Dynamic Range: CCDs have a wider dynamic range than film, meaning they can capture both bright and faint objects in the same image.

* Efficiency: CCDs have a higher quantum efficiency than film, meaning they convert more incoming photons into electrons, leading to a stronger signal.

While photographic film still has some niche uses in astronomy, CCDs have become the dominant technology for astronomical imaging due to their superior performance.