Everything we see - from stars and galaxies to planets and people - amounts to only 5% of the cosmos.
The rest is hidden in the dark...
DARK MATTER AND DARK ENERGY
A Mystery of
Missing Matter
Until 20 to 30 years ago, scientists thought that the Universe was composed of ordinary matter: protons, neutrons and electrons. Now we know that this accounts for only 5% of the Universe mass-energy budget. The rest is composed of two mysterious components, dark energy and dark matter, which are causing the expansion of the Universe to accelerate, and which cannot be adequately explained by our current knowledge of fundamental physics.
Watch the videos to find out more about dark energy and dark matter, and meet some of the people involved in the Euclid mission ahead of this year's Royal Society Summer Science Exhibition.
What is dark matter?
What is dark energy?
GRAVITATIONAL LENSING
Cosmic
Clues
Imagine a galaxy, behind another galaxy. Think you won't see it? Think again.
While we can't see dark matter directly, Euclid can see clues of its presence. One such clue is where galaxies appear as warped or distorted illusions of their true selves, an effect known as gravitational lensing.
This happens when massive objects bend and magnify light, revealing otherwise hidden mass — including dark matter.
Astronomers and software developers at The University of Edinburgh lead on Euclid's gravitational lensing data analysis.
Euclid's data is revolutionising the study of strong lensing. New techniques using machine learning and AI have been developed to find these rare objects. Citizen science has also contributed significantly, with over 1000 volunteers participating in visual inspections. You can get involved in this citizen science project, Space Warps, by following the link below.
At this year's Royal Society Summer Science Exhibition you will be able to experience the phenomenon of gravitational lensing firsthand, watching the cosmos warp as light bends around you and mimicking Euclid’s ability to detect distant galaxies distorted by gravity.
Take me to Space Warps!EUCLID SPACE TELESCOPE
Dark Universe
Detective
Euclid is a flagship space telescope launched by the European Space Agency in July 2023. While its main mirror is only about half the size of that of the famous Hubble Space Telescope at a diameter of 1.2m, Euclid can image a much larger part of the sky in one go and observes more of the Universe within a few days than Hubble will ever see.
Euclid is based at a point in our Solar System known as L2, a dark and calm spot four times further from Earth than the Moon, where it will follow the Earth’s orbit around the Sun. Euclid is creating a map of the deep Universe over the course of six years, covering all of the sky that is not obscured by our own galaxy, the Milky Way.
On board Euclid will are two instruments: the visible light instrument, VIS, is among the largest digital cameras that have ever gone into space. University College London (UCL) contributed to the design and build of VIS. With carefully crafted optics and avoiding the blurring due to Earth’s atmosphere, this camera will take exceptionally detailed images of objects that are too small and too faint to be studied from ground-based telescopes. A second camera, NISP, captures infrared light that usually gets blocked by the Earth’s atmosphere.
Scientists based at the University of Edinburgh lead the UK’s involvement in Euclid’s data analysis and host the UK’s Science Data Centre, which processes huge amounts of data from the telescope ready for astronomers to make discoveries.
At this year's Royal Society Summer Science Exhibition you'll be able to get up close to a scale model of the Euclid space telescope!
Explore Euclid's map so far...