Euclid is a mission from the European Space Agency (ESA) intended to study the hidden nature of dark matter and dark energy. This plan of the mission was proposed first in 2007 and then selected in ESA´s Cosmic Vision programme in 2011. It´s planned to be launched in 2020 and will be placed at an orbit around earth at langrangian point 2 (L2) 1.5 million km from earth.


This Spacecraft from ESA will be equipped with a telescope 1.2 meters in diameter, which will give functionality to two Science instruments; a camera in the visible light spectrum and a near infrared camera/spectrometer.

The mission will extend for six years, during which two billion galaxies will be analyzed in 3-D, including the dark matter and dark energy associated within them.

What is dark matter?

This type of mater is hypothesized to account for an approximate quantity of 27% of the observable universe. It does not emit nor interact with electromagnetic radiation, thus it´s not visible. Although even the advanced telescopes cannot see dark matter, its existence is deduced by its interaction with gravity.

It´s believed that after the Big Bang, the universe was expanding, although slowly and the dominating force, gravity, became weaker as the masses in the universe became farther and farther apart. The weakening of gravity in the universe gradually allow this hidden constituent (dark matter) to begin to appear, although invisible, dark matter is forcing the universe to expand.

What is dark energy?

Dark energy is an unknown form of energy that abounds in all space and is driving the acceleration and expansion of the universe. It´s been estimated that dark energy accounts for approximately 68% of the total energy in the universe. The calculated form of dark energy is the cosmological constant, which is the value of the density of this energy in empty space.

Studying the motions, locations and structures of 2 billion galaxies across most of the universe, with the aid of this mission, may allow scientists togather sufficient data to understand the presence of dark matter and dark energy. The accuracies of these measurements will help solve one of the biggest mysteries of the universe.