If you want to know what happened in the early years of the universe, you’ll need a very large and very specialized telescope. To the joy of astronomers and space fans everywhere, the world has one: the James Webb Space Telescope.
In this episode of “the weekly conversationWe talked to three experts about what astronomers have learned about the early galaxies in the universe, and how just six months of data from James Webb is already changing astronomy.
The James Webb Space Telescope was successfully launched into space on December 25, 2021. After about six months of travel, setup, and calibration, the telescope began collecting data, and NASA released the first awesome images.
One of Webb’s nicknames is “first light telescope.” This is because Webb was specifically designed to be able to see as far back as possible into the early days of the universe and detect some of the first visible light.
You can see these galaxies in the images that NASA has published. jonathan trump, an astronomer at the University of Connecticut, is on one of the teams working on some of the first data from James Webb. He was watching the release of the first live images and noticed a few things that many non-astronomers might have missed. “In the background, behind these beautiful arcs and spirals and massive elliptical galaxies, are these tiny red blobs. That’s what interested me the most, because those are some of the earliest galaxies in the universe.”
“One of the things we’ve learned is that there are more of these galaxies than we expected to see.” In addition to working on identifying these first galaxies, Kartaltepe has been using Webb’s incredible resolution to study their structure and shape. “We expect there to be disks because disks form quite naturally in the universe anytime you have something spinning. But we’ve been seeing a lot of them, which has been a bit surprising.”
In addition to observing the shape of galaxies in the early universe, astronomers like Trump are beginning to be able to assess the chemical composition of these galaxies. She does this by looking at the spectrum of light that James Webb is collecting. “We look at these distant galaxies and look for particular patterns of emission lines. We often call them a chemical fingerprint because it really is like a particular fingerprint of particular elements in a galaxy’s gas.”
The universe began with just hydrogen and helium, but as stars formed and elements merged, larger and heavier elements began to emerge, completing the periodic table as it is today. And like Kartaltepe, Trump is finding evidence that things happened faster in the early universe than astronomers expected. “I would have imagined that the universe would have had trouble making the periodic table and building things. But that’s not what we found. Instead, the universe appears to have proceeded quite quickly.”
James Webb’s discoveries are already changing the way astronomers think about the early universe and challenging much existing theory. But what’s really exciting is that we’re just beginning to see what this telescope is capable of, as brown michaelexplains an astronomer from Monash University.