In 2022, James Webb revealed the most distant galaxies

Everything led to believe that the James Webb Space Telescope, launched at the end of 2021 and whose first discoveries were presented to the world this year, would be able to see further than Hubble, but nobody imagined it would be so quickly.

In the very first battery of observations, the telescope found the most distant galaxy ever seen.

Its “redshift” (remember, light “reddens” with wavelength stretching as it travels over long distances) was estimated at 12.5, which was equivalent to saying that we were seeing the galaxy Glass-z12 as it was when the Universe was only 350 million years old. Today, it is 13.8 billion years old, which is a measure of how the space telescope is delving into the secrets of the cosmic past.

Detail: this was just the beginning. A new work, released at the beginning of December and still going through the peer review process, took a dive with Webb into the region that generated the deepest image of the Universe obtained by Hubble, and has already found another record holder: a galaxy with deviation to the red 13.2, equivalent to 330 million years after the Big Bang.

And more: they are not isolated findings. There are many galaxies with a comparable redshift (between 10 and 13 so far), in so few observations, which already makes scientists review their expectations about how the Universe’s infancy was. Until then, the standard cosmological model suggested that there shouldn’t have been so many galaxies already mature and bright like this at that remote time. How to explain them? Cosmologists still don’t know. But it is clear that the answers will only come thanks to the unprecedented observational power of James Webb.

The composition of exoplanets

Closer to home, the space telescope has been making unprecedented observations of the atmospheres of exoplanets, worlds that orbit stars other than the Sun.

In its initial observations, Webb has already obtained the most accurate spectra (technical term to describe the “light signature”) of an exoplanet atmosphere. When pointed at Wasp-39b, a Saturn-sized world in a tighter orbit around its star, it found the first evidence of photochemistry — reactions produced by stellar radiation — ever seen on an exoplanet. The planet appears to have sparse clouds, rather than a dense, uniform blanket of it, and it has sulfur dioxide in its atmosphere, a molecule produced thanks to ultraviolet light emanating from the parent star.

The scenario is the most interesting possible for the future of exoplanet research with Webb, as the telescope is pointed at worlds that may be friendly to life – a subject that will certainly be addressed in the coming years, possibly as early as 2023.