EUCLID Telescope Captures First Images

Months before the long-anticipated Euclid Telescope delivers its groundbreaking view of the cosmos, scientists and engineers involved in the mission are already celebrating a significant milestone as the telescope and instruments have proven to be in excellent working condition.

“After more than 11 years of designing and developing Euclid, it’s exhilarating and enormously emotional to see these first images...It’s even more incredible when we think that we see just a few galaxies here, produced with minimum system tuning. The fully calibrated Euclid will ultimately observe billions of galaxies to create the biggest ever 3D map of the sky.” - ,” Giuseppe Racca, Euclid Project Manager 

“It is fantastic to see the latest addition to ESA’s fleet of science missions already performing so well. I have full confidence that the team behind the mission will succeed in using Euclid to reveal so much about the 95% of the Universe that we currently know so little about.” - Josef Aschbacher, ESA Director General

“Our teams have worked tirelessly since the launch of Euclid on 1 July and these first engineering images give a tantalising glimpse of the remarkable data we can expect from Euclid.” - Carole Mundell, ESA’s Director Of Science

Euclid’s VISible instrument (VIS)

Euclid's Visible Instrument (VIS) is designed to capture incredibly sharp images of billions of galaxies, allowing precise measurements of their shapes. In the first image obtained, we catch a glimpse of the wealth of data that VIS will provide. While a few galaxies are readily identifiable, many others appear as indistinct blobs amid the stars, eagerly awaiting Euclid's future unveiling.

Remarkably, the image covers only about a quarter of the width and height of the full Moon, yet it is rich in detail and potential discoveries.

The uniqueness of this image is further underscored by an initial concern faced by the Euclid team when activating the instrument. They detected an unexpected pattern of light contaminating the images. After thorough investigations, it was determined that some sunlight had infiltrated the spacecraft, likely through a minute gap. However, the team's quick thinking allowed them to realize that this light interference occurred only at specific orientations. By avoiding these angles, Euclid's VIS will be able to execute its mission effectively. The image we have now was taken at an orientation where sunlight interference was not an issue.

Euclid’s Near-Infrared Spectrometer and Photometer (NISP)

Euclid's Near-Infrared Spectrometer and Photometer (NISP) instrument serves a dual purpose in its mission. Firstly, it captures infrared light images of galaxies, and secondly, it measures the emitted light from galaxies across different wavelengths. This second role is crucial as it enables us to determine the distance to each galaxy directly.

The fusion of distance data obtained by NISP with galaxy shape measurements from VIS will allow us to create a comprehensive map of the distribution of galaxies throughout the vast expanse of the Universe. Through this mapping, we can observe how this distribution evolves over time. Ultimately, the creation of this 3D map will provide profound insights into the nature of dark matter and dark energy, unraveling some of the universe's most mysterious and captivating secrets.

Prior to reaching the NISP detector, the light captured by Euclid's telescope undergoes filtration. This filtering process precisely measures the brightness of light at a specific infrared wavelength.

The light captured by Euclid's telescope has undergone a unique process. Before reaching the detector, it passed through a 'grism', a remarkable device capable of splitting light from every star and galaxy based on their wavelengths. As a result, each vertical streak of light in the image represents an individual star or galaxy.

This innovative method of observing the Universe enables us to discern the composition of each galaxy accurately. Consequently, we can determine the distance of these galaxies from Earth with precision, opening up new avenues for comprehensive evaluations of celestial objects.

“We’ve seen simulated images, we’ve seen laboratory test images – it’s still hard for me to grasp these images are now the real Universe. So detailed, just amazing.” - Knud Jahnke, NISP Instrument Scientist

“Each new image we uncover leaves me utterly amazed. And I admit that I enjoy listening to the expressions of awe from others in the room when they look at this data.” - William Gillard, NISP Instrument Scientist

It is essential to reiterate that these captivating snapshots, though beautiful, are primarily early test images taken to evaluate and refine the instruments aboard the spacecraft. Since they are mostly unprocessed, some undesired artifacts, like cosmic rays cutting straight across the frame, can be observed, particularly in the VIS image.

The Euclid Consortium's dedicated efforts will eventually transform the longer-exposed survey observations into scientifically valuable images, free from artifacts, richer in detail, and remarkably sharp.

Over the upcoming months, ESA and its industry partners will continue conducting comprehensive tests and checks to ensure Euclid's optimal performance. After completing the 'commissioning and performance verification phase,' the real scientific exploration will commence. At that juncture, ESA will unveil a new set of images, showcasing the mission's impressive capabilities and what it can achieve in the realm of science.