Detecting an Earth-like planet is a significant challenge due to the fact that it is approximately 10 billion times fainter than its parent star. To capture the faint light reflected from the planet, it is necessary to block almost all of the star’s light using a coronagraph. However, any instability in the telescope’s optics, such as misalignment between mirrors or a change in the mirror’s shape, can lead to leakage of starlight and cause glare that masks the planet.
To overcome this obstacle, precise control of both the telescope and the instrument’s optical quality, or wavefront, is required at an exceptional level of 10s of picometers (pm). This level of precision is roughly on the order of the size of a hydrogen atom, emphasizing the extraordinary effort needed for this endeavor. Despite these challenges, scientists continue to search for Earth-like planets using advanced technologies and techniques to detect them.