Canadian astronomers are chomping at the bit to release the first images from the James Webb Telescope

About 13.8 billion years ago, the basis of all that we are, all that we have understood, was born.

Most people know this event as the Big Bang, but it took time to create what we see today. A lot. Over billions of years it transformed from a place of high density and temperature, then expanded and then cooled. Eventually, the simplest elements were formed, such as hydrogen and helium, still the most abundant elements in our universe.

The first stars lit up, piercing the marshy darkness. Then they clumped together to form galaxies, islands of stars in this dark void, even superclusters of hundreds to thousands of galaxies all connected together. Supernovae – violent explosions of massive stars – exploded in these starry islands, creating more stars and eventually planets. Like the Earth, where life arose in abundance.

On Tuesday, the most powerful telescope ever built will help trace humanity back to the beginning of time by peering through gas and dust, shedding light on what has been invisible until now.

And maybe even reveal an atmosphere around an exoplanet.

The James Webb Space Telescope (JWST), a joint mission between NASA, the Canadian Space Agency (CSA) and the European Space Agency (ESA), will release multiple images – five at least – of peering through the dark and dust when the universe was in its infancy.

On Friday, the agencies announced their goals:

  • SMACS 0723a cluster of galaxies that distort light from objects behind them, allowing astronomers to see faint distant galaxies behind them.
  • WASP-96ba gas giant planet located 1,150 light years from Earth.
  • The South Ring Nebula.
  • Stephan Quinteta collection of five galaxies.
  • And one of the most magnificent nebulae in the night sky, the Carina Nebula.

« You’re going to see absolutely stunning images, » said René Doyon, a professor at the University of Montreal and principal investigator of NIRISS, one of the four scientific instruments of the James Webb Space Telescope.

The JWST is a $10 billion powerhouse. Sitting in orbit beyond the moon, the telescope is larger and therefore much more powerful than the Hubble Space Telescope which orbits Earth. It also has different abilities than Hubble and as a result is able to travel further back in time to when the universe was in its infancy.

Canada played a major role in Webb’s abilities. First, there’s the Canadian-made Fine Guidance Sensor (FGS), which is critical to keeping the telescope on target.

There is also the NIRISS (Near-Infrared Imager and Slitless Spectrograph), which will help astronomers study the atmospheres of exoplanets and observe distant galaxies.

The Southern Ring Nebula, also known as the « eight flash » nebula because it looks like a figure eight when viewed through some telescopes, is visible in the southern hemisphere. The nebula measures nearly half a light-year in diameter and 2,000 light-years in distance. The gases are moving away from the dying star at its center at a speed of 14 kilometers per second. (NASA/The Hubble Legacy Team [STScI/AURA/NASA])

Thanks to Canada’s contribution, astronomers here will have plenty of time to use the telescope.

“Canadians should be proud of [be part] of this project,” said Doyon, who has worked on Webb for 20 years. “Every picture, every [bit] data coming out of Webb will have been guided by the eye, the Canadian eye of FGS. So… we should definitely be proud. »

Looking deeper into the past

The further away an object is, the longer its light takes to reach us. It means everything we see is as it is has been, not as it is.

Telescopes allow us to see farther in time by collecting faint light. The larger the telescope, the more light it can collect and the farther it can see.

Although Hubble was able to see distant galaxies, it doesn’t have Webb’s resolution, which means images will be much sharper, revealing much more detail.

Additionally, Webb sees in the near infrared, meaning he can see through dust and gases that might otherwise obscure objects. Hubble primarily sees the universe in optical light, like the human eye, although it can also see in ultraviolet and near-infrared wavelengths. Webb, however, is optimized to see in infrared.

All this to say that Webb will peer deeper into our past than ever before and provide astronomers with incredible detail.

« There is a difference between detecting and studying something in depth. Hubble had seen specks of objects that we believe formed only some 100 million years after the birth of the universe. « said Lamiya Mowla, an astronomer at the University of Toronto. Dunlap Institute of Astronomy and Astrophysics.

« However, these need to be explored even further with James Webb. With James Webb, we can actually see the objects as they form, just after they heat up; the discs form; the bulges of the galaxies are forming. This is the type of epoch we will be able to see with the James Webb Space Telescope. »

the hubble ultra deep field 2012
This image shows the 2012 Hubble Ultra Deep Field, an enhanced version of the Hubble Ultra Deep Field image with additional observing time. It revealed for the first time a population of distant galaxies at redshifts between 9 and 12, including the most distant object observed to date. These galaxies will need to be confirmed spectroscopically by the future James Webb Space Telescope before they can be considered fully confirmed. (NASA, ESA, R. Ellis (Caltech))

Mowla, who specializes in the evolution and formation of galaxies, is also part of the Canadian NIRISS Unbiased Cluster Survey (CANUCS), which will study some of the earliest galaxies in the universe.

She is eagerly awaiting the release of the first science images and will watch them from St. Mary’s University in Halifax with other CANUCS members, including Chris Willott, an astronomer from the National Research Council’s Herzberg Center for Astronomy and Astrophysics. Canada leading the research. The instrument will use NIRISS to study galaxies at different periods in the history of the universe.

I nearly broke my jaw the first time I saw this data.– René Doyon, professor at the University of Montreal

Willott said he’s seen some early test footage already.

« It’s super exciting to finally see the data released, » Willott said. « I’ve been watching these images for months. And they’re so spectacular, and it’s really exciting that the whole world can see them on Tuesday. »

He is eager to get more data to study the evolution of galaxies, which come in all sorts of different shapes and sizes.

« I want to see how far we can actually go back to the beginning of the universe. We know that Webb is going to break the records that we could get from Hubble in terms of how far back and how far back in the universe we can look. But we we don’t really know how far we’re going to go with Webb. And that’s something that I think will take time.

‘A new chapter’

Webb will not only be able to see some of the earliest galaxies, but he will also be able to detect atmospheres around distant planets orbiting other stars. Ultimately, astronomers hope Webb will be able to detect any potential signatures of life from these exoplanets.

« I can say that [on] On July 12, we are turning a new page on a new chapter for the study of exoplanet atmospheres,” Doyon said. “The quality of the data is simply amazing. I nearly broke my jaw the first time I saw this data. »

While the general public may be delighted to see new, more detailed images of our universe, for astronomers it’s all about getting their hands on the data to analyze.

For example, Doyon said, there is the famous exoplanetary system known as TRAPPIST-1, which has seven planets, three of which are in the habitable zone, a region around a star where water can exist. on the surface of a planet.

exoplanet comparison
This graphic shows, on the top row, artists’ conceptions of the seven planets of TRAPPIST-1 with their orbital periods, distances from their star, radii and masses relative to those of Earth. The bottom row shows data for Mercury, Venus, Earth, and Mars. (NASA/JPL-Caltech)

« The only way to know if they have water on their surface is to measure the atmosphere, » he said. « And Webb has the ability to do that and in particular the NIRISS instrument. »

But this is only the beginning of exoplanet research. Astronomers hope to eventually find signatures of life.

« The next question is: do they have water [their surfaces], the next step will be biosignatures, a gas that is only produced by biological activity. It’s long. I mean, we know it will be very difficult to detect this with Webb, it will probably take a lifetime of JWST to do, but who knows? That’s the good thing about it: we’re going to be taken by surprise. »

Mowla is also waiting to be surprised by researching galactic evolution.

« Really, I’m waiting to see something that can’t be explained by current theory. Because that’s what always happens. Every time you have new data and you look at the universe in a different realm You always find something that will go against your theories and it will force you to rethink a lot of things,” she said.


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