Detecting an Earth-like planet presents a significant challenge for astronomers due to the fact that a planet is approximately 10 billion times fainter than its parent star. To overcome this obstacle, telescopes must be equipped with coronagraphs, which are used to block out almost all of the star’s light in order to capture the faint light that bounces off the planet. However, any instabilities in the telescope’s optics can leak starlight and cause glare that masks the planet.
To detect an Earth-like planet with a coronagraph, precise control of both the telescope and the optical quality of the instrument is required down to an extraordinary level of 10s of picometers (pm). This is roughly equivalent to the size of a hydrogen atom, highlighting the extreme precision needed for this task. Despite these challenges, scientists continue to work tirelessly to uncover new information about our universe and search for planets that may be capable of supporting life beyond Earth.