Galaxy field of MXDFz4.4 (Hubble and Webb clean image)

This galaxy field contains the oddball galaxy MXDFz4.4 that existed only 1.4 billion years after the Big Bang, when the Universe was still a “swirl” of opaque and clear gas as the Era of Reionisation was ending.

Detailed visible-light images from the NASA/ESA Hubble Space Telescope revealed that several bursts of younger stars cleared the space in and around the galaxy. The team sifted through extensive Hubble observations that produced deep exposures of the field where this galaxy is located.

The colour assignments in the image emphasise the specific wavelengths of light Hubble observed where ionising photons from MXDFz4.4 were detected, which transformed the gas around them from opaque to clear.

Researchers have long sought evidence to explain how the Universe transitioned from foggy to transparent — and Hubble has provided the first example this close to the era of reionisation of how that might have happened within an individual galaxy.

[Image description: Thousands of galaxies appear across the black background of space. The galaxies range in size, from big blobs and larger face-on spirals to short lines and tiny dots. The galaxies appear in a variety of colours, including orange, white, pink, and blue.]