A bewildering number of shiny galaxies, a purple-orange star nursery and a spiral galaxy similar to our Milky Way: new images were revealed on Thursday by the European Euclid Space Telescope.
It is the second set of images released by the European Space Agency since Euclid launched the first-ever mission to investigate the mysteries of dark matter and dark energy last year.
Scientific results were also published for the first time during the six-year mission, which aims to use its broad view to map two billion galaxies across a third of the sky.
Euclid project scientist Rene Laureijs told AFP he was “personally most excited” by the image of a huge cluster of galaxies called Abell 2390.
The image of the cluster, which is 2.7 billion light-years away from Earth, includes more than 50,000 galaxies.
Just one galaxy – like ours – can house hundreds of billions or even trillions of stars.
Abell 2390 alone contains the mass of about 10 trillion suns, Jason Rhodes of NASA’s Jet Propulsion Laboratory told an online news conference.
The image also pointed to traces of dark matter, whose invisible presence can only be detected by looking at how gravity distorts the light.
“There is so much dark matter in this cluster that the light from some of these background galaxies is severely bent,” Rhodes said.
Dark matter and dark energy are believed to make up 95 percent of the universe, but we know almost nothing about them.
Another way the Abell 2390 image hinted at dark matter was by revealing the faint light of “orphan stars” floating among galaxy clusters.
These stars are ejected from the galaxies, creating “a kind of cloud that surrounds the entire cluster,” French scientist Jean-Charles Cuillandre told AFP.
Astronomers believe that this strange phenomenon indicates the presence of dark matter between the galaxies.
A star is born
Euclid also captured the deepest image ever of Messier 78, a nursery where stars are born 1,300 light-years from Earth in the constellation Orion.
Stars are still forming in the bluish center of the image. After being worn for millions of years, they emerge from the purple and orange clouds at the bottom of the image.
Laureijs emphasized that “only Euclid can show this in one go.”
That’s because Euclid has a very wide field of view, unlike farsighted fellow space telescope James Webb, its neighbor in a stable floating spot 1.5 million kilometers (930,000 miles) from Earth.
Another image, of the massive galaxy cluster Abell 2764, shows a black expanse in which one yellow star stands out.
Cuillandre admitted that this was due to an error in aiming the telescope. But he said the image demonstrated “Euclid’s absolutely unique ability to concentrate light” as it was still able to pick up very faint objects next to the bright star.
Euclid’s image of the young Dorado cluster contained a surprise. Although the cluster was already well studied, Euclid discovered a never-before-seen dwarf galaxy, the scientists said.
“I’ve never seen anything like it,” Cuillandre said.
In the fifth new image, spiral galaxy NGC 6744 – which bears a striking resemblance to the Milky Way – fans out against a backdrop of shining stars.
On the trail of dark matter
It’s still early for the mission and the five new images were captured in just one day.
In the coming years, scientists plan to sift through Euclid’s data in hopes of discovering all kinds of celestial bodies, such as “rogue” planets, which float freely through the universe and have no connection to a star.
But researchers have already analyzed the first set of images of Euclid, which were released in November.
In one of ten pre-print studies published Thursday, scientists looked at orphan stars in the Perseus cluster.
These lost stars “are now trapped in the gravity of dark matter,” Laureijs said.
This remains only “indirect detection of dark matter,” he stressed, adding that it was too early “to say anything about dark energy.”
The mission did not go entirely smoothly.
In March, a delicate operation successfully melted a thin layer of ice that had slowly obscured the telescope’s view by heating one of the telescope’s mirrors.
There are signs that the ice is rebuilding, Laureijs said, adding that the team has time to figure out what to do next.
© Agence France-Presse