Exploring the dark universe, Euclid discovers scenes of cosmic light Katrina Miller
Euclid, the European Space Agency telescope launched into space last summer, has finally shown off its capabilities in a series of breathtaking images and early science results published Thursday.
The telescope will help astronomers understand two of the universe's greatest mysteries: dark matter, the invisible glue that holds galaxies together, and dark energy, the force that pushes galaxies together.
“Before we understand what it is, we have to understand how it behaves,” said Jean-Charles Cuillandre, an astronomer at CEA Paris-Saclay, referring to dark matter.
The mysterious substance bends and distorts light, an effect known as gravitational lensing. In extreme cases, lensing can make galaxies appear distorted and even create mirror images of a single source.
Euclid captured this effect while observing Abell 2390, a galaxy cluster located 2.7 billion light-years away. 90% of the mass of this cluster is dark matter.
Gravity causes dark matter to stick together, but dark energy counteracts this effect. Studying the density of dark matter throughout the universe will help astronomers learn how dark energy affects the structure of the universe.
Euclid's specialty is its ability to capture large expanses of sky in impressive detail. Galaxies that appear near bright stars like Beta Phenisis may not be visible from some observatories on Earth, but Euclid's keen eyes can resolve them.
The telescope's sensors create a net for light, Dr. Cuillandre said. “It captures everything.”
In a series of papers, the Euclid team also shared discoveries about new dwarf galaxies, star clusters, and free-floating planets. Astronomers say this shows how the mission can reach beyond its core goals.
“We call this legacy science that even Euclidean can do,” said Michael Seiffert, a cosmologist on the mission at NASA’s Jet Propulsion Laboratory.
The telescope captured these two galaxies passing by each other 62 million light-years away, creating diffuse edges and tails.
These interactions are common. “It’s very rare to find an isolated galaxy,” said Dr. Cuillandre. “That’s what we found out.”
Euclid took pictures of the spiral galaxy NGC 6744, located 30 million light years from Earth.
Interstellar gas and dust coalesce in the rotation of a spiral galaxy, promoting star formation along the arms of the spiral galaxy. Each of the blue specks in this image is a hot, massive baby star.
A neighboring dwarf galaxy has torn off one of NGC 6744's arms. According to Dr. Cuillandre, even galaxies have scars. “They track what happened” over billions of years, he said.
Euclid also noted Messier 78, a stellar nursery. Telescopes with near-infrared vision can look beyond clouds of gas and dust to reveal bright blue infant stars hidden within.
Stars spew out protons and neutrons, forming dust and other matter around them. This is similar to how Earth's winds sculpt clouds.
Eventually, a hole forms around this star, whose light illuminates the entire universe.
The latest images are the result of just one day of observations. “We are just getting started,” said Dr. Seiffert.