The James Webb Space Telescope (JWST) was specifically designed to observe and study the infrared portion of the electromagnetic spectrum. There are several reasons why JWST does not include sensors capable of detecting blue and green visible wavelengths:
Scientific Focus: The primary scientific objectives of the JWST are focused on studying the early universe, galaxy formation, and the formation of stars and planetary systems. These areas of research primarily require observations in the infrared region of the spectrum to penetrate cosmic dust and observe distant objects. The telescope's instruments are optimized for capturing infrared light and are equipped with detectors specifically designed for that purpose.
Technical Challenges: Designing and implementing detectors for multiple wavelength ranges, including blue and green visible wavelengths, would have added significant complexity and cost to the mission. The development of detectors capable of operating in the infrared region already posed significant technological challenges, and adding additional wavelength ranges would have made the telescope more complex and potentially less reliable.
Limited Resources: The space telescope missions have limited resources in terms of weight, power, and data bandwidth. By focusing on the infrared, the JWST's instruments can be optimized for the specific scientific goals while still fitting within the constraints of the mission.
It's worth noting that other space telescopes, such as the Hubble Space Telescope (HST), have been designed to operate in the visible and near-infrared portions of the spectrum. These telescopes complement each other by covering different wavelength ranges and enable scientists to study a broad range of phenomena in the universe.