Final answer:
The most effective method to detect distant planets, also known as exoplanets, involves using telescopes that facilitate indirect observation methods such as the Doppler shift method and the transit method, rather than attempting direct imaging.
Step-by-step explanation:
When it comes to detecting distant planets, which are often referred to as exoplanets, the most effective telescopes are those that can observe the effects of a planet on the star it orbits, rather than directly imaging the planet itself. Telescopes enable us to view distant objects by gathering more light and producing a larger image than can be seen with the unaided eye. The indirect detection techniques, like the Doppler shift method or the transit method, are currently the best approaches for discovering exoplanets.
For the Doppler shift method, which measures changes in a star's light due to gravitational interactions with planets, telescopes need to be capable of detecting small Doppler shifts to reveal more distant and less massive planets. The transit method, which detects exoplanets by observing the minute dimming of a star as a planet crosses in front of it, often requires telescopes positioned in space, like the NASA Kepler space observatory used to be, to avoid atmospheric distortions.
Both the Doppler shift and transit methods are currently more favorable than direct imaging due to the challenge of detecting the very faint light of a planet overwhelmed by the brilliance of its host star. Therefore, a space-based observatory with sensitive instruments specifically designed for these indirect methods would be the best telescope to use for detecting distant planets.