How Australian scientists sharpened James Webb Telescope’s vision from a million kilometres away

Australian Team Sharpens NASA’s James Webb Telescope Vision from a Million Kilometres Away (Image: Canva)

When the James Webb Space Telescope launched in 2021, millions watched in suspense. The world’s most powerful telescope had 344 points of failure. For scientists in Australia, however, the real challenge began only after Webb reached space.

How did Australian scientists help fix Webb’s blur?
Researchers from the University of Sydney worked on Webb’s highest-resolution mode, known as the aperture masking interferometer, or AMI. This small yet vital metal plate sits inside one of Webb’s cameras. It helps measure distortions that can blur images of planets and black holes.

Led by PhD student Louis Desdoigts, the team identified an electronic issue where bright pixels leaked into dark ones, making images slightly blurry. Though common in infrared cameras, the effect was unexpectedly severe for Webb. The flaw made it hard to spot faint planets near bright stars.

To correct this, the team built a model simulating AMI’s optical physics and combined it with machine learning. This allowed them to detect and reverse the blur in Webb’s data. Their results, published on the open-access archive arXiv, restored AMI’s full function and clarity.

What did the improved images reveal?
After applying the correction, Webb captured sharper images of the star HD 206893, revealing a faint planet and a reddish-brown dwarf previously unseen. The success opened the way for detecting unknown planets with higher precision than ever before.

Another University of Sydney PhD student, Max Charles, expanded the work to complex images. Using the correction, the team brought Jupiter’s volcanic moon Io into focus, tracking eruptions over an hour-long sequence. The black hole jet from galaxy NGC 1068 and a ribbon of dust around star WR 137 were also captured in sharper detail.

Why is this discovery important?
Unlike Hubble, which astronauts once repaired in orbit, Webb is about 1.5 million kilometres from Earth. Servicing it physically is impossible. That makes the Australian-designed AMI crucial for monitoring Webb’s optics from afar.

The study proves that software-based calibration can overcome physical limits in telescope materials. The code created for the AMI could inform next-generation instruments such as NASA's Roman Space Telescope, enhancing the hunt for Earth-like planets.

As the scientists write, each corrected pixel brings us nearer to investigating far-off worlds more starkly than ever before.

(Inputs from PTI)