A Space Mission to Map the Structures Connecting the Universe and Solve Fundamental Mysteries Is About to Launch

A new mission that will peer into the dark side of the universe is almost ready to depart Earth and head to its new home in deep space.

Euclid, a telescope developed by the European Space Agency (ESA), is scheduled to launch on a SpaceX rocket from Cape Canaveral, Florida, at 11:11am Eastern Time on Saturday. The launch will be live streamed at the below link. 

The mission is tasked with studying dark matter, an unidentified substance that accounts for most of the mass in the universe, and dark energy, an unknown force that could be driving the accelerated expansion of our universe.  

To better understand these shadowy phenomena, Euclid will stare across 10 billion years of time to witness the long-term evolution of the “cosmic web,” a network of large-scale structures that links the universe. By observing billions of galaxies covering a third of the sky, the four-foot-wide telescope will generate an unprecedented 3D map of dark matter on cosmic scales and will attempt to spot variations in the pace of our universe’s accelerated expansion. 

“Euclid is really touching on the fundamentals of our physics” including “how our universe works and what it is made of,” said René Laureijs, Euclid’s project scientist, in a call with Motherboard. “We will look at structures in the universe to see how things move, basically, from 10 billion years ago until now.”

This unique dataset will allow scientists to test the standard model of cosmology, also known as ΛCDM, a framework that is built on well-corroborated ideas, such as Albert Einstein’s theory of general relativity. The standard model can account for much of what we see in the cosmos, but it cannot yet explain dark matter and dark energy. Euclid is one of many next-generation observatories designed to resolve these enigmas, potentially by discovering new physics beyond the standard model.

Euclid’s main task is to study the mechanism that is accelerating the expansion of the universe, which is known as dark energy. In the view of the standard model, the value of dark energy is considered to be a fundamental constant that does not change over time. If Euclid’s observations reveal that it does vary across the universe’s lifetime, it will undercut our best model of reality and pave the way toward new physics.

“What we want to do with Euclid is to get statistically relevant observations that will give us a very detailed description of the acceleration so that we can test the standard model,” Laureijs explained. “We hope to find deviations from the model, and observational evidence that the standard model cannot be fitted to our observations.” 

“It might also be that we have a perfect match for the standard model, and we’d have to scratch our heads about what that actually means as well,” he continued. “In both cases, our outcome will be quite exciting for cosmologists.”

In addition to probing dark energy, Euclid is equipped to map the distribution of dark matter across an enormous stretch of cosmic space and time. The telescope is especially attuned to the effects of gravitational lensing, which occurs when the gravitational fields of massive entities warp the light of objects behind them, from our perspective on Earth. Euclid will use these lensing measurements to map the contours of the cosmic web, a huge network of filaments and nodes made of dark matter that extend across the universe. 

Even as it observes the universe on these epically large scales, the telescope may also produce interesting discoveries in our own galactic backyard. For instance, Euclid plans to team up with NASA’s Nancy Grace Roman Space Telescope, which is due for launch in 2027, to search for hidden “rogue” planets that wander through interstellar space after becoming unbound from their stars.

“If Roman has a detection and Euclid has a detection, we can tell the distance to an exoplanet and we can then very accurately determine the mass of an exoplanet,” Laureijs said. “We hope, of course, to find Earth-like exoplanets.”

Euclid was originally supposed to launch on the Russian Soyuz rocket, but that plan fell apart after Russia’s invasion of Ukraine in February 2022. The mission initially faced major delays for the launch, but the team was eventually able to secure a ride to space on SpaceX’s Falcon 9 this summer.

If all goes to plan, Euclid will lift off this weekend and spend the next four weeks headed to Lagrange Point 2, a region of gravitational equilibrium one million miles from Earth that is also home to the NASA-led James Webb Space Telescope. It will take a few months for the  telescope to calibrate its instruments, but Laureijs said he expected Euclid to send back its first images by the end of 2023, marking the beginning of a new voyage into the perplexing dark realms of the universe that has been in the making for more than a decade.

“We see the end of the tunnel now,” Laureijs concluded. “I think we are up to the challenge of opening up the telescope and getting the data.”