Revolutionary telescope will soon alter what we know of the universe

By Louise Edwards, Astrophysicist

It was my honor and pleasure to deliver the 8th annual Dan McLennan Lecture in Astronomy this winter. Halifax, and at Saint Mary’s University, I grew up in the astronomical sense. My two years of pursuing a Masters in Science gave me decades of friendships I still hold dear and exposed me to mentors I still admire today.

For the talk, I chose to talk about the synergy between ground-based and space-based astronomy. It’s an important concept and also gives us the freedom to explore two of the most exciting and ambitious projects that modern astronomy has given us: the James Webb Space Telescope (JWST) and the Legacy Survey of Space and Time (LSST).

If you follow astronomy or space news, chances are you’ve been exposed to the JWST’s deluge of beautiful, sharp and colorful images: a range of objects from planets in our own solar system (and others) to magnified galaxies viewed in early stages their creation.

The JWST is about the size of a tennis court, and we put it in a rocket and blasted it above the earth. Its delicate origami sails unfolded during the month-long voyage – past the moon, over a million kilometers away.

The JWST will be able to study the formation and evolution of galaxies in the Universe in minute detail. The view offered is sophisticated, offering exceptional resolution in the tiny patches of sky that any JWST observation beholds.

Exploration of Dark Matter

At the same time, in order to fully understand the general nature of the universe, we need a project that can survey vast swathes of space. This is where the Legacy Survey of Space and Time comes in.

It is an ambitious project that will survey the entire southern sky every few nights for ten years starting in 2024. The project is housed at the Vera C. Rubin Observatory, which includes a brand new telescope built specifically to carry out this project. The telescope’s main mirror is huge, measuring 8.4 m in diameter, making it one of the largest telescopes today. The telescope’s camera is record-breaking. The survey will find billions of stars and galaxies and lead to the first motion picture of the night sky.

One of the biggest questions about the general nature of the universe addressed by the LSST is: what is the nature of dark matter? You may have heard the term dark matter before, it refers to things (matter) that we can say exist in space even though they don’t reflect or shine light (it’s dark).

For a long time, this mysterious material was thought to be normal material that did not emit light – like dark planets or black holes. But recent measurements have shown us that a more reasonable guess is that dark matter is a massive collection of tiny particles (similar to electrons or protons) that don’t readily respond to the instruments we’ve invented.

The search is on. There are “dark matter detectors” all over the world – trying to catch these elusive particles, including a large detector in Canada at SNOLAB.

But nothing has turned up until now. The LSST will not detect dark matter particles directly, but since the universe is about 85 percent dark matter, a better understanding of the size, shape, and structure of the universe should – and could – help us better understand the nature of dark matter help direct where and how the detectors we build should search.

Vera Rubin’s groundbreaking work

So if we haven’t found dark matter yet, why are astronomers so convinced of its existence?

We haven’t been for a long time. It took data – big data – to convince astronomers that dark matter was a viable idea.

One of the most prominent figures in 20th century astronomy, Dr. Vera Rubin, spent many nights at large telescopes in the 1970s and 1980s collecting this data: studying the motion of stars in galaxies and realizing that more mass than visible was needed to guide the stars’ path within you.

The idea had surfaced prior to Rubin’s work, but the community was unconvinced. After their brilliant and diligent work, the existence of dark matter became undeniable, and today it is fundamental to our understanding of the cosmos. So it’s quite fitting that the observatory, which is searching for a deeper understanding of dark matter, was named after Vera C. Rubin, who provided such compelling evidence of its existence.

dr Rubin was also a pioneer in creating a more inclusive astronomy community, especially for women in the field. When I applied to graduate school, I didn’t have to worry about where I could go, where women could be let in [or Black people] but she did. When I was at the Palomar Observatory, I noticed that there was a women’s washroom (there was none for Ruby).

As I was working on this talk, I found a quote from Rubin particularly inspirational: “Having a family and a career has been very tough, but it’s doable.”

I wish it was a more proclaimed statement. For over a decade, I constantly gave up social ties to take the next step, and I often worried that I was trading what I really wanted (to be a parent) for what I had worked so hard for (a being a parent). academic).

It was difficult for me, but also possible, to invest in a chosen profession and to have a nice family life.

What a truly magical evening for me, my love of astronomy, sharing the first images from JWST and imagining the future with LSST at the university that has given me so much.

If it’s a clear evening tonight, step outside and gaze up at the myriad points of light overhead.

Spectacular.

*This episode was produced by Mary Lynk.