NASA announced this week that it has joined the European Space Agency’s (ESA) Euclid mission. The mission will investigate dark matter and dark energy throughout the universe.

In 2020, the mission will launch the Euclid space telescope, which will spend six years mapping and measuring as many as 2 billion galaxies that cover one-third of the sky. The hope is that Euclid will be able to provide insight into the evolution of the universe and the influence of dark matter and dark energy.

“ESA’s Euclid mission is designed to probe one of the most fundamental questions in modern cosmology, and we welcome NASA’s contribution to this important endeavor, the most recent in a long history of cooperation in space science between our two agencies,” said Alvaro Gimenez, ESA’s Director of Science and Robotic Exploration.

Though NASA’s part in the Euclid mission is still being developed, the agency will be providing 16 infrared detectors and four spare detectors for one of Euclid’s science instruments.

The Euclid spacecraft will be launched into orbit around the sun-Earth Lagrange point L2, a point where the gravitational pull of the sun and Earth can help the satellite maintain a stationary position behind the Earth. The spacecraft will map dark matter, using precise measurements of distant galaxies.

Dark Matter makes up around 85% of the universe. It is called dark matter because it does not interact with light, and is made up of unknown particles. It does, however, interact with known matter through gravity, binding galaxies together. Dark energy, on the other hand, is accelerating the expansion of the universe. Even less about dark energy is known than about dark matter.

(Image courtesy ESA/C. Carreau)