Euclid ‘dark universe’ telescope reveals 1st spectacular images from colossal ‘cosmic atlas’ map

The Euclid Space Telescope has bared the “first page” of the cosmic atlas it is building. This section of the map of the universe being built by Euclid was released on 15^th October 2024, and it features tens of millions of stars within the Milky Way and around 14 million faraway galaxies beyond our own. The vast cosmic mosaic was built from 260 Euclid observations collected between 25^th March and 8^th April of 2024 and contains 208 gigapixels of data. The region charted is roughly 500 times as wide as the full moon appears in the sky over Earth.

Perhaps most startlingly, the mosaic accounts for just 1% of the total survey Euclid will carry out over the next 6 years as it tracks the shapes, distances and movements of galaxies as distant as 10 billion light-years away. Not only will this result in the largest 3D map of the universe ever created, but the vast scale of this map will help researchers investigate the mysteries of dark energy and dark matter, sometimes jointly known as the “dark universe.”

Cosmic atlas or “dark universe detective” casefile?

Launched in July 2023, Euclid started making scientific observations in February. This wide-angle space telescope with a 600-megapixel camera is capable of recording visible light and near-infrared light employing a spectrometer. This allows us to measure “redshift” caused as galaxies race away from the Milky Way. By doing this for a wide variety of galaxies, Euclid can measure the effect of dark energy, the enigmatic force driving the acceleration of the cosmos, by expanding the space between galaxies.

“Euclid is observing the universe in a brand new way, and it’s gonna get a gigantic census of the galaxies,” said Luz Ángela García Peñaloza (Universidad ECCI cosmologist). “Any image that reveals information about the distribution of galaxies in the large-scale structure of the universe will provide handfuls of information on the nature of the dark side of the cosmos.” “We still need to wait a bit more to recover a larger sample of galaxies to infer cosmological parameters and rule out some existing models.”

Though representing just a fortnight of observations, the Euclid spacecraft’s sensitive cameras captured a wide variety of objects in great detail for this new release. One feature that will captivate researchers in this Euclid mosaic is the dim clouds that can be seen stretching between stars within our galaxy. These appear in the wider images as light blue streaks against space’s black background.

These blue tracks are a mixture of gas and dust and are at times referred to as “galactic cirrus” because they resemble cirrus clouds in the skies over Earth. Euclid’s capability to visualize these clouds comes from the fact that they reflect optical light from the Milky Way and shine radiantly in far-infrared light.

Taking a wider view of the universe and then narrowing down, the deep detail enabled by Euclid allows astrophysicists to zoom very deep into the mosaic and see intricate structures, such as the shape of the spiral galaxy ESO 364-G036, which is positioned around 420 million light-years away.

This first page of the Euclid cosmic atlas and a small slice of the map of the cosmos that it will eventually create is just a teaser for greater things to come from the mission. Around 12% of Euclid’s planned data gathering has been completed.