Detecting an Earth-like planet is a significant challenge due to the fact that the planet is approximately 10 billion times fainter than its parent star. The key obstacle lies in the need to block almost all of the star’s light in order to capture the faint light reflected from the planet. This requires the use of a coronagraph, which blocks out most of the starlight, but any instability in the telescope’s optics can lead to leakage of starlight and cause glare that masks the planet.
To overcome this challenge, detecting an Earth-like planet using a coronagraph requires precise control of both the telescope and the instrument’s optical quality or wavefront to an exceptional level of 10s of picometers (pm). This level of precision is roughly on par with the size of a hydrogen atom, highlighting just how delicate and precise this endeavor truly is.
In order to achieve this level of precision, scientists must use highly advanced telescopes and instruments that are specifically designed for this purpose. They must also be able to account for any potential sources of error or contamination that could impact their results. Despite these challenges, however, detecting an Earth-like planet remains one of humanity’s greatest scientific pursuits, as it could provide us with valuable insights into our own planet’s history and potential future.
Overall, detecting an Earth-like planet presents a significant challenge due to its extreme faintness and requirement for precise control over both telescope and instrument. However, with continued advancements in technology and scientific understanding, we may one day be able to overcome these obstacles and unlock even more mysteries about our universe.