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Euclid: Understanding dark energy and our expanding universe

One of the greatest mysteries of astronomy is why the universe is expanding at an accelerating rate. Astronomers understand that there must be some force causing the expansion. They have called this mysterious force "dark energy."

Astronomers want to understand the nature of dark energy, and they hope that the Euclid astronomy mission will help them do just that. Euclid is a space telescope being developed by the ESA that will give researchers the information they need to map out the large-scale structure of the universe with greater accuracy than ever before.

By mapping up to 2 billion galaxies, and peering 10 billion light-years back into the universe's history, astronomers will be able to see how dark energy and dark matter affected and continues to influence the growth and structure of the universe.

Euclid is a 1.2-metre diameter telescope that houses two scientific instruments: a visible-wavelength camera and a near-infrared camera/spectrometer. These instruments will measure the "redshift" of galaxies. Redshift allows astronomers to determine how much the light emitted by an object is stretched, or shifted toward the red part of the light spectrum as the object moves away from us. This data enables a calculation of the rate of expansion of the universe.

The Euclid space telescope

Euclid is designed to help astronomers probe the history of the universe to learn more about its rate of expansion, commonly thought to be driven by an enigmatic phenomenon known as dark energy. (Credit: ESA)


The Euclid mission aims to:

Canada's role in the mission

Will Percival

Dr. Will Percival, professor and Distinguished Research Chair in Astrophysics at the University of Waterloo. (Credit: University of Waterloo)

Mike Hudson

Dr. Mike Hudson, professor of astronomy at the University of Waterloo. (Credit: University of Waterloo)

The Canadian Space Agency is funding two scientists' participation in the Euclid mission:

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