First Piece of Euclid’s Sky Map Revealed

MILAN — Today at the International Astronautical Congress in Milan, ESA Director General Josef Aschbacher and Director of Science Carole Mundell revealed the first chunk of the map of the sky being drafted by the Euclid telescope. The mosaic was composed using observations conducted in just two weeks, between March 25 and April 9, 2024, and covers a 132-square-degree patch of the Southern sky.

Revealing the observations

The mosaic contains a whopping 208 gigapixels, which cover 132 square degrees of the sky. To give a sense of perspective, displaying the full image in all its definition would require 16500 high-resolution TV screens. This accounts for approximately an area 500 times bigger than the full Moon, or 0.3% of the whole sky. These observations constitute 1 % of Euclid’s wide survey, during which the telescope will observe the shapes, distances, and motion of galaxies as far as 10 billion light-years. The result will be the biggest 3D cosmic map ever.

This first piece of the survey contains 14 million galaxies. Their study could enhance our understanding of dark matter. It also contains tens of millions of stars in our own Milky Way.

“This stunning image is the first piece of a map that in six years will reveal more than one third of the sky. This is just 1% of the map, and yet it is full of a variety of sources that will help scientists discover new ways to describe the Universe,” commented Valeria Pettorino, Euclid Project Scientist at ESA.

All the details captured

The detail captured by Euclid’s cameras is immense, allowing to see the structure of a spiral galaxy even when zooming deep into the mosaic. This detail remains clearly visible despite the image being zoomed in 600 times.

A special feature visible in the mosaic are “galactic cirrus”. These are dim clouds of dust and gas, which resemble the cirrus clouds found on Earth. They appear as a faint blue against the black background of space. Euclid can detect them with its extremely sensitive visible light camera. This instrument can sense the visible light the clouds reflect from the stars of the Milky Way. The clouds also emit in the infra-red, as detected by ESA’s Planck mission.

Euclid

The space telescope was launched in July 2023 on a SpaceX Falcon 9, with a planned mission duration of 6 years. It then reached its orbit at the Sun-Earth L2 Lagrange point. Science operations began on February 14, 2024. Euclid will conduct a wide survey, covering approximately a third of the sky, and a more in-depth scan of some particularly interesting regions, dubbed the Euclid Deep Field.

Euclid is a European mission operated by ESA, with some contributions by NASA. The Euclid Consortium, which features more than 2000 scientists from 15 European countries, the USA, Canada, and Japan, provides scientific experiments and performs data analysis.

Thales Alenia Space built the spacecraft’s service module, while Airbus Defence and Space built the payload section. The latter part includes the crucial telescope. NASA provided the Near-Infrared Spectrometer and Photometer detector, or NISP, as their contribution.

The future

The mosaic released today is just a glimpse into what’s to come. Since its commissioning, Euclid has already performed 12 % of its wide survey. A further 53 square degrees of the survey are slated for release in March 2025. These new areas will include a preview of the Deep Field areas. The full first year of cosmology data will be released in 2026. By then 170 petabytes of data will have been collected.

For the complete coverage of the 2024 International Astronautical Congress, please click here.