* Doppler Technique: This technique, also known as the radial velocity method, looks for tiny wobbles in a star's motion caused by the gravitational pull of an orbiting planet. The larger the planet, the stronger its gravitational tug, and the more noticeable the wobble.
* Sensitivity Limitations: Current technology is more sensitive to detecting the wobbles caused by massive planets. Smaller, less massive planets like Earth-sized ones produce much smaller wobbles, which are harder to detect.
While the Doppler technique has been successful in discovering many massive planets, we are now seeing more discoveries of smaller planets thanks to improvements in technology and observation techniques.
