Euclid’s Revolutionary New Images

The European Space Agency’s (ESA) Euclid space mission has just released its first science data, alongside another stunning set of five images revealing wide, deep, and detailed views of stellar nurseries and galaxies near and far. These materials are part of Euclid’s Early Release Observations, encompassing 513 science pages and 10 images (the first five of which were released in 2023).

This cosmic treasure trove results from only 24 hours of observation, showcasing Euclid’s advantages: speed and scope. The space telescope has created these expansive cosmic portraits, in as little as an hour of observation time.

Euclid carries two instruments: the visible instrument (VIS) and the near-infrared spectrometer and photometer (NISP). VIS is a 609-megapixel visible-band imager, sensitive to low light levels and capable of imaging 0.5 square degrees at a time, equal to the area of 2.5 full Moons as seen from Earth. Similarly, NISP boasts the widest field of view of any infrared instrument ever lifted into space, with 0.57 square degrees per exposure.

Together, the two instruments produce deep, wide, high-resolution images hundreds of times faster than other telescopes. These snapshots are at least four times sharper than any obtainable by Euclid’s terrestrial counterparts, and hundreds of times larger than comparable ones from other space telescopes.

The images released showcase Euclid’s prodigious field of view and scalpel-sharp resolution. The mission will use these to capture cosmic evolution in 3D, from 10 billion years ago to the present, investigating the distribution and workings of dark matter as well as the influence of dark energy in accelerating the expansion of our universe.

Five New Images from Euclid

In the first image, Euclid’s infrared eyes pierce the dense dust and gas of the Messier 78 nebula, 1,300 light-years away in Orion, to unveil hot, young stars enshrouded by gas and entwined by darker filaments of interstellar dust.

Peering through the shroud for the first time, “Euclid has uncovered half a million objects including galaxies and stars,” explains science team member Maruša Žerjal (Institute of Astrophysics of the Canary Islands, Spain).

Amazingly, astronomers can use Euclid to study much smaller objects in such wide images, including brown dwarfs and planets only a few times more massive than Jupiter. A full census of these objects will reveal some of the mass hidden in the universe’s small-body population, adds Jerry Zhang (also at the institute). The team also plans to measure the ratio of stars to such sub-stellar objects over cosmic time.

This image of the spectacular spiral NGC 6744, 30 million light-years in the southern constellation Pavo, NGC 6744 captures an “archetype of the kind of galaxy currently forming most of the stars in the local Universe,” according to an ESA press release. The image shows the galaxy’s spiral arms as well as finer features, like the feathered lanes of dust between the arms. Euclid’s pinpoint precision even enables astronomers to “count individual stars and reveal the distribution of dust,” says researcher Francesca Annibali (INAF-OAS, Italy).

Astronomers will employ Euclid to create comprehensive maps of diverse stellar populations including newborn stars, elderly stellar clusters, and the dusty distribution of stars-to-be, relating their formation to the physics of spiral structures.

The Dorado Group of galaxies, located 62 million light-years away in the Dorado constellation, displays “galaxy evolution as it’s happening,” says Karina Voggel (Strasbourg Observatory, France).

Some of its constituents are merging or displaying signs of recent mergers. As an intermediary between immense galaxy clusters and smaller galaxy groups, the Dorado Group is a valuable snapshot of a mid-scale structure and galactic collisions.

Around the Dorado Group appear clusters of many thousands of stars. Teymoor Saifollahi (Strasbourg Observatory, France) points out that these globular clusters are part of the Dorado Group, as both the clusters and the group were born together approximately 10 billion years ago.

One of the main science goals of the Euclid mission is to seek out dark matter, and Abell 2674, 1 billion light-years away in Pisces, offers a prime target. This galaxy cluster, upper right, is a gravitationally bound package of hundreds of galaxies “orbiting a dark matter halo,” according to Hakim Atek (Institute of Astrophysics of Paris).

Such dense regions of space are perfect places to explore dark matter’s effects. Atek describes such “blank fields,” as “more representative of the large-scale distribution of galaxies in the universe.”

This single pointing, which already contains 250,000 galaxies and other celestial objects, is among the first of many: Euclid will map an area 30,000 times greater than this image, or about one-third of the sky.

The shining star toward the bottom (V*BP-Phoenicis/HD 1973) is located within our Milky Way and demonstrates Euclid’s design, which minimizes light scatter. “This is precisely what defines Euclid’s sharp view of the universe,” Atek says.

The galaxy cluster Abell 2390, 2.7 billion light-years distant in Pegasus, is an immense agglomeration of galaxies like our Milky Way. It’s accompanied by a breathtaking panorama of 50,000 galaxies. And thanks to Euclid, scientists can now measure their distances and shapes.

Galaxy clusters can contain the “mass of 10 trillion Suns,” explains Jason Rhodes (NASA JPL), with much of that mass in the form of dark matter. The gravity of such clusters warps the path of background photons in a phenomenon known as gravitational lensing. This effect can be seen in the curved arcs in the image, some of which show multiple images of the celestial objects behind them.

Astronomers can also use this image to study intracluster light emitted by orphaned stars. Galaxy interactions have kicked these stars from their galactic homes to wander alone through intergalactic space.

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This status quo changing quintet is just the beginning, as Euclid only started its six-year science survey in February. It will observe over a third of the sky and view billions of galaxies out to 10 billion light-years, creating a monumental, three-dimensional map across space and time.

The only downside? The next public data release is slated for March 2025. But as Euclid inspires both imagination and innovation, who knows what enlightening discoveries will be made in the meantime.