Wednesday 24 September 2025
A team of scientists has made a significant breakthrough in developing a high-contrast imaging testbed, crucial for future space-based telescopes that aim to directly image Earth-like planets orbiting Sun-like stars.
The Space Coronagraph Optical Bench (SCoOB) is a vacuum-compatible coronagraph testbed designed to operate in optical wavelengths. It’s essentially a miniaturized version of the instruments that will be used on future telescopes, such as the James Webb Space Telescope and the Terrestrial Planet Finder. The SCoOB testbed has been developed by researchers at the University of Arizona, in collaboration with other institutions.
The main goal of coronagraphs is to block out the intense light from a star, allowing astronomers to study the faint light reflected off nearby planets. However, achieving high contrast between the bright starlight and the dim planetlight is extremely challenging. SCoOB’s innovative design incorporates various technologies to minimize stray light and optimize the performance of the testbed.
One key component is the vector vortex coronagraph (VVC), which uses a series of tiny glass plates to manipulate the light waves. This clever technique helps to cancel out the starlight, allowing astronomers to detect faint signals from planets. The VVC also has built-in polarization aberration correction, which ensures that the light waves are properly aligned.
Another crucial aspect is the use of pairwise probing for electric field conjugation (EFC). This involves using multiple sub-bands of light to measure and correct for aberrations in the optical system. By doing so, SCoOB’s testbed can achieve a contrast of 2.2 x 10^-9 in quasi-monochromatic light, which is an impressive feat.
The researchers have also developed advanced simulations to model the performance of SCoOB. These simulations take into account various factors that affect image quality, such as surface errors on optical components, polarization aberrations, and diffuse reflection from stops within the testbed.
The results of these simulations are promising, showing that SCoOB’s testbed can achieve a contrast limit dominated by chromatic EFC residuals in broader bandwidths. This means that future telescopes will be able to study the atmospheres of distant planets with unprecedented precision.
The development of SCoOB is an important step towards realizing the ambitious goals of exoplanet hunters. As astronomers continue to push the boundaries of what’s possible, innovative technologies like this testbed will play a vital role in uncovering the secrets of our universe.
Cite this article: “Breakthrough in Coronagraph Technology Advances Quest for Direct Imaging of Earth-Like Planets”, The Science Archive, 2025.
Coronagraph, Space Telescope, High Contrast Imaging, Exoplanet, James Webb Space Telescope, Terrestrial Planet Finder, Vector Vortex Coronagraph, Pairwise Probing, Electric Field Conjugation, Optical Wavelengths
