Skip to main content

James Webb researcher reveals how it will investigate the early universe

Once the James Webb Space Telescope begins science operations this summer, it will the world’s most powerful space telescope, and it will open new avenues for astronomy research. One of the researchers who will be working with James Webb, Massimo Stiavelli, the Webb Mission Office head at the Space Telescope Science Institute, has shared more information about how Webb will look back in time at some of the earliest stars and galaxies.

Because light takes time to travel, the further away from Earth we look, the earlier we are seeing in the development of the universe. Webb will be able to see more distant galaxies than ever before, allowing researchers to get a glimpse of the early stages of the universe. By looking at the composition of these very early stars and galaxies, researchers can get an idea of what was happening in the few minutes after the Big Bang.

“The chemical composition of the early universe, just after the big bang, is the product of the nuclear processes that took place in the first few minutes of the universe’s existence,” Stiavelli said, as shared in a NASA blog post. “These processes are known as ‘primordial nucleosynthesis.’ One of the predictions of this model is that the chemical composition of the early universe is largely hydrogen and helium. There were only traces of heavier elements, which formed later in stars. These predictions are compatible with observations, and are in fact one of the key pieces of evidence that support the hot big bang model.”

Webb will be searching out examples of these very old stars to see if they support current theories about the Big Bang. “The earliest stars formed out of material with this primordial composition,” Stiavelli said. “Finding these stars, commonly dubbed as the ‘First Stars’ or ‘Population III stars,’ is an important verification of our cosmological model, and it is within reach of the James Webb Space Telescope. Webb might not be able to detect individual stars from the beginning of the universe, but it can detect some of the first galaxies containing these stars.”

Stiavelli’s project is to look at one of the furthest galaxies discovered to date, called MACS1149-JD1, using Webb. The team will measure how much of the galaxy is made up of heavier elements, using an instrument called a spectrograph, so they can confirm whether it is made up of these very early stars. The project will be a part of Webb’s first year of science operations.

Editors' Recommendations

Georgina Torbet
Georgina is the Digital Trends space writer, covering human space exploration, planetary science, and cosmology. She…
How to watch NASA and SpaceX launch Crew-7 to the space station
SpaceX's Crew-7 astronauts.

NASA Live: Official Stream of NASA TV

NASA and SpaceX are making final preparations for the Crew-7 flight to the International Space Station (ISS).

Read more
James Webb captures image of the most distant star ever discovered
A massive galaxy cluster called WHL0137-08 contains the most strongly magnified galaxy known in the universe’s first billion years: the Sunrise Arc, and within that galaxy, the most distant star ever detected, nicknamed Earendel.

The James Webb Space Telescope has captured a stunning image of the most distant star ever discovered. Discovered by Hubble in 2020, the star named Earendel is located an astonishing 28 billion light-years away. While in the previous Hubble image, the star was only visible as a small blob, these new observations from Webb are detailed enough to reveal information about the star like its type and information about the galaxy in which it resides.

The Webb image shows a galaxy cluster called WHL0137-08, which is so massive that it bends spacetime and acts like a magnifying glass for the more distant galaxies behind it. Some of these distant galaxies being magnified include one called the Sunrise Arc, which hosts Earendel. The Sunrise Arc is located near the end of one of the spikes from the bright central star, at around the five o'clock position. A zoomed-in version of the image shows the Arc and Earendel within t.

Read more
Scientists explain cosmic ‘question mark’ spotted by Webb space telescope
The shape of a question mark captured by the James Webb Space Telescope.

Considering the myriad of unknowns that still exist for scientists exploring the vastness of the universe, the recent discovery in deep space of what seems to be a giant question mark feels highly appropriate.

Captured by the powerful James Webb Space Telescope, the bright, distinctive object clearly bears the shape of a question mark, leaving some stargazers wondering if the cosmos is teasing us, or perhaps motivating us to keep on searching the depths of space for the secrets that it may reveal.

Read more