Euclid satellite is launched!

Saturday, July 1, 2023

Mission will explore the evolution of the dark Universe

The European Space Agency has successfully launched its Euclid satellite at 11:12 EDTtoday from Cape Canaveral, Florida. Eucllid launched without a hitch atop a SpaceX Falcon 9.

Artist's impression Euclid in space

Once in orbit, Euclid will map billions of galaxies out to 10 billion light years, across more than one third of the sky. Astronomers will use these data to create a 3D map of the Universe.  This extensive and detailed chart of the extragalactic sky will reveal the distribution of matter in the Universe and show us how the expansion of the Universe has evolved over time. Astronomer can use this to learn more about the role of gravity and to quantify the properties of dark energy and dark matter.  Understanding the role of these enigmatic entities will help us answer the fundamental question: what is the Universe made of?

Euclid has been 12 years in the making and will spend more than 6 years in space surveying one third of the sky with unprecedented accuracy and sensitivity. It will see more than 2,000 scientists involved in some part of analyzing the data it sends back to Earth.

This group includes Canadians from many leading astronomy research groups across the country.  Canadian organizations involved in the Euclid mission include the University of Waterloo, the University of British Columbia, the National Research Council of Canada (NRC), the Canada France Hawaii Telescope, the Canadian Space Agency.

Waterloo Centre for Astrophysics (WCA) Director, Will Percival, is one of four scientists coordinating the primary science on the mission.

Euclid will provide a huge step forward in our understanding of the components of our universe that do not interact with light. Using observations that are not limited by our atmosphere, Euclid will examine the pattern of galaxies in the Universe and the observed shapes of those galaxies to study the exact way that the Universe is expanding, and what structures are growing within it. It’s been a long journey since we sketched out the initial requirements for the mission, and we’ve got a long way still to go to analyse the data, but it’s incredibly exciting to have reached this point.

Each country that participates in a large, complex mission like Euclid will traditionally offer some sort of contribution to the preparations. For example, hardware for the satellite itself, expertise in the form of specialized engineers or, as in Canada’s case, data.  Canada’s contribution to Euclid came from the Canada France Hawaii Telescope (CFHT), located atop the summit of Mauna Kea, a 4,200-metre, dormant volcano located on the island of Hawaii. CFHT contributed data related to one of the two principal scientific groups within the Euclid mission – those who are studying dark matter using a process called gravitational lensing.  Mike Hudson of the WCA explains:

Canada has provided data from ground-based telescopes that is critical to the success of the Euclid mission. Canadians were at the forefront of a collaboration using Hawaii-based telescopes to cover the northern sky in many filters, including data from CFHT as well as from the Subaru telescope through the Waterloo-Hawaii-IfA G-band Survey (WHIGS). In return, 25 Canadians joined the Euclid Consortium: a win-win for science.

Euclid’s goal is to determine the properties of dark energy and dark matter on universal scales.  It is equipped with an advanced telescope and innovative optical and near-infrared scientific instrumentation.  The VISible instrument (VIS) will take images in optical and near-infrared light; these images will eventually cover more than 1/3 of the extragalactic sky outside the Milky Way and depict billions of cosmic targets out to a distance where light has taken up to 10 billion years to reach us.

Euclid’s image quality will be at least 4 times sharper than that achieved by ground-based sky surveys.

In addition, Euclid will perform near-infrared spectroscopy of hundreds of millions of galaxies and stars over the same sky with the Near-Infrared Spectrometer and Photometer (NISP). This will allow scientists to investigate the chemical and kinematical properties of many targets in detail.

Euclid will build up a large archive of unique data, unprecedented by volume for a space-based mission, enabling research over all disciplines in astronomy.

Euclid travelling to L2 (artist's impression)

After a journey of about a month after launch, Euclid will Join ESA’s James Webb Space Telescope (JWST) and Gaia mission at the Sun-Earth Lagrange point L2.  L2 is an equilibrium point of the Sun-Earth system and is in the opposite direction of the Sun at 1.5 million km from Earth (about four times the Earth-Moon distance), making it an ideal place for space telescopes aimed at astronomical observations.

Once in position at L2, Euclid will undergo an intense phase of two months of testing and calibration of the scientific instrumentation, and of preparing for the routine observations.

The launch of Euclid was covered in an ESA press release, in the University of Waterloo news, on the CBC "As it happens" radio show, on CTV Kitchener and in the Globe and Mail.