ESA - Euclid space telescope updates

[Targeteer]

https://www.esa.int/Science_Exploration/Space_Science/Euclid/Operations_begin_to_de-ice_Euclid_s_vision

Operations begin to de-ice Euclid’s vision
19/03/2024 970 views 6 likes
ESA / Science & Exploration / Space Science / Euclid

A few layers of water ice – the width of a strand of DNA – are starting to impact Euclid’s vision; a common issue for spacecraft in the freezing cold of space, but a potential problem for this highly sensitive mission that requires remarkable precision to investigate the nature of the dark Universe. After months of research, Euclid teams across Europe are now testing a newly designed procedure to de-ice the mission's optics. If successful, the operations will validate the mission teams’ plan to keep Euclid’s optical system as ice-free as possible for the rest of its life in orbit.
Euclid’s vision fogs as it steps ‘outside’

In recent months, while fine-tuning and calibrating Euclid’s instruments after launch and preparing for the start of the mission’s first survey, science operations experts noticed a small but progressive decrease in the amount of light measured from stars observed repeatedly with the visible instrument (VIS).

Euclid is experiencing a common problem that spacecraft face once they get to space: water absorbed from the air during assembly on Earth is now gradually being released from certain components in the spacecraft, teased out by the vacuum of space.

In the freezing cold of Euclid’s new environment, those released water molecules tend to stick to the first surface they land on – and when they land on this highly sensitive mission’s optics, they can cause trouble.

“We compared the starlight coming in through the VIS instrument with the recorded brightness of the same stars at earlier times, seen by both Euclid and ESA’s Gaia mission,” explains Mischa Schirmer, calibration scientist for the Euclid consortium and one of the main designers of the new de-icing plan.

“Some stars in the Universe vary in their luminosity, but the majority are stable for many millions of years. So, when our instruments detected a faint, gradual decline in photons coming in, we knew it wasn’t them – it was us.”

It was always expected that water could gradually build up and contaminate Euclid’s vision, as it is very difficult to build and launch a spacecraft from Earth without some of the water in our planet’s atmosphere creeping into it.

For this reason, there was an ‘outgassing campaign’ shortly after launch where the telescope was warmed up by onboard heaters and also partially exposed to the Sun, sublimating most of the water molecules present at launch on or very near Euclid’s surfaces. A considerable fraction, however, has survived, by being absorbed in the multi-layer insulation, and is now being slowly released in the vacuum of space.

After a huge amount of research – including lab studies into how minuscule layers of ice on mirror surfaces scatter and reflect light – and months of calibrations in space, the team determined that several layers of water molecules are likely frozen onto mirrors in Euclid’s optics. Likely just a few to few tens of nanometres thick – equivalent to the width of a strand of DNA – it’s a remarkable testament to the mission’s sensitivity that it is detecting such tiny amounts of ice.

While Euclid's observations and science continue, teams have come up with a plan to understand where the ice is in the optical system and mitigate its impact now and in the future, if it continues to accumulate.
Approximately 10 kg of MLI covers Euclid's two science instruments, but this material can absorb 1% of its own weight in water.
Approximately 10 kg of MLI covers Euclid's two science instruments, but this material can absorb 1% of its own weight in water.
Brand-new plan to decontaminate Euclid from 1.5 million km away

“A complex mission requires a united response from teams across Europe, and I'm incredibly thankful for the effort and skill that so many have poured into this,” says Ralf Kohley, Euclid Instrument Operations Scientist who coordinated the response.

“It took work from teams at ESA's ESTEC technical heart in the Netherlands, the ESAC science operations centre in Madrid and the Flight Control Team at ESOC mission control in Darmstadt – but we couldn't have done it without the Euclid consortium and the critical inputs we got from spacecraft prime contractor Thales Alenia Space and its industrial partner Airbus Space.”

The easiest option would be to use the decontamination procedure developed well before launch and heat the entire spacecraft. Teams at mission control would send the commands to turn on every onboard heater for several days, slowly increasing temperatures from about –140 °C to, in some parts of the spacecraft, a ‘balmy’ –3°C.

Doing this would clean the optics but would also heat the entire mechanical structure of the spacecraft. As most materials heat, they expand and don’t necessarily return to precisely the same state after a week-long cool-down, meaning a potentially subtle difference in Euclid’s optical alignment. This won’t do for such a sensitive mission where effects can be noticed on the optics from a temperature change of just a fraction of a degree, requiring at least several weeks of fine recalibration.

“Most other space missions don’t have such demanding requirements on ‘thermo-optical stability’ as Euclid,” explains Andreas Rudolph, Euclid Flight Director at ESA's mission control.

“To fulfil Euclid’s scientific goals of making a 3D map of the Universe by observing billions of galaxies out to 10 billion light-years, across more than a third of the sky, means we have to keep the mission incredibly stable – and that includes its temperature. Switching on the heaters in the payload module therefore needs to be done with extreme care.”

To limit thermal changes, the team will begin by individually heating low-risk optical parts of the spacecraft, located in areas where water released is unlikely to contaminate other instruments or optics. They will start with two of Euclid’s mirrors that can be warmed up independently. If the loss in light persists and starts to have an impact on science, they will continue to warm up other groups of Euclid’s mirrors, checking each time what percentage of photons they get back.

Small amounts of water will continue to be released within Euclid over the life of the mission, so a long-term solution is needed to regularly de-ice its optics without taking up too much precious mission time – Euclid has six years to complete its survey.

"VIS will be measuring weak gravitational lensing – how matter in the Universe has bunched together under the influence of gravity as the Universe expands – and to understand this, the more galaxies we observe, the better,” explains Reiko Nakajima, VIS instrument scientist.

"De-icing should restore and preserve Euclid's ability to collect light from these ancient galaxies, but it’s the first time we're doing this procedure. We have very good guesses about which surface the ice is sticking to, but we won't be sure until we do it.”

Mischa concludes, “Once we have isolated the affected area, the hope is that we can then simply warm up this isolated part of the spacecraft in the future as needed. What we are doing is very complex and fine-grained, so that we can save valuable time in the future – I’m extremely excited to find out just where this water ice is accumulating, and how well our plan will work.”

Despite how common this contamination issue is for spacecraft operating in cold conditions, there is surprisingly little published research about precisely how ice forms on optical mirrors and its impact on observations. Not only could Euclid reveal the nature of dark matter, but it could also shed light on an issue that has long plagued our roving eyes in space, peering down at Earth and out across the Universe.

[Targeteer]

https://twitter.com/esa/status/1770580011910676711

[Nighthawk117]

ESA’s Euclid Space Telescope Fix Exceeds Expectations

A procedure to de-ice the Euclid space telescope’s optics has performed significantly better than hoped, achieving a 15% gain in sensitivity.

https://europeanspaceflight.com/esas-euclid-space-telescope-fix-exceeds-expectations/

[Star One]

Euclid celebrates first science with sparkling new images:
 

[Blackstar]

[leovinus]

Science publications https://www.euclid-ec.org/science/publications/

[BobTheBuilderverse]

Hello!
Total newbie here and sorry, if the answer to the question is obvious :-)

When I take the first of the newly released pictures (Abell 2390) and just look at the hue values, there is a cloud showing up. What exactly is that? Again, sorry if its just an artefact or otherwise irrelevant 🙏

And thanks for these amazing pictures. So much to see in them, so much lensing, I spent hours just panning through them. 🤗

[jacqmans]

Zoom into the first page of ESA Euclid’s great cosmic atlas
15/10/2024

On 15 October 2024, ESA’s Euclid space mission reveals the first piece of its great map of the Universe, showing millions of stars and galaxies.

This first chunk of the map, which is a huge mosaic of 208 gigapixels, is revealed today at the International Astronautical Congress in Milan, Italy, by ESA’s Director General Josef Aschbacher and Director of Science Carole Mundell.

The mosaic contains 260 observations made between 25 March and 8 April 2024. In just two weeks, Euclid covered 132 square degrees of the Southern Sky in pristine detail, more than 500 times the area of the full Moon.

This mosaic accounts for 1% of the wide survey that Euclid will capture over six years. During this survey, the telescope observes the shapes, distances and motions of billions of galaxies out to 10 billion light-years [1]. By doing this, it will create the largest cosmic 3D map ever made.

This first piece of the map already contains around 100 million sources: stars in our Milky Way and galaxies beyond. Some 14 million of these galaxies could be used to study the hidden influence of dark matter and dark energy on the Universe.[2]

“This stunning image is the first piece of a map that in six years will reveal more than one third of the sky. This is just 1% of the map, and yet it is full of a variety of sources that will help scientists discover new ways to describe the Universe,” says Valeria Pettorino, Euclid Project Scientist at ESA.

The spacecraft’s sensitive cameras captured an incredible number of objects in great detail. Zooming very deep into the mosaic (this image is enlarged 600 times compared to the full view), we can still clearly see the intricate structure of a spiral galaxy.

More:
https://www.esa.int/Science_Exploration/Space_Science/Euclid/Zoom_into_the_first_page_of_ESA_Euclid_s_great_cosmic_atlas#msdynmkt_trackingcontext=259377f3-5b40-4c93-a6ad-c998da6b5832

[eeergo]

Zoom into the first page of ESA Euclid’s great cosmic atlas
15/10/2024

On 15 October 2024, ESA’s Euclid space mission reveals the first piece of its great map of the Universe, showing millions of stars and galaxies.

This first chunk of the map, which is a huge mosaic of 208 gigapixels, is revealed today at the International Astronautical Congress in Milan, Italy, by ESA’s Director General Josef Aschbacher and Director of Science Carole Mundell.

The mosaic contains 260 observations made between 25 March and 8 April 2024. In just two weeks, Euclid covered 132 square degrees of the Southern Sky in pristine detail, more than 500 times the area of the full Moon.

This mosaic accounts for 1% of the wide survey that Euclid will capture over six years. During this survey, the telescope observes the shapes, distances and motions of billions of galaxies out to 10 billion light-years [1]. By doing this, it will create the largest cosmic 3D map ever made.

This first piece of the map already contains around 100 million sources: stars in our Milky Way and galaxies beyond. Some 14 million of these galaxies could be used to study the hidden influence of dark matter and dark energy on the Universe.[2]

“This stunning image is the first piece of a map that in six years will reveal more than one third of the sky. This is just 1% of the map, and yet it is full of a variety of sources that will help scientists discover new ways to describe the Universe,” says Valeria Pettorino, Euclid Project Scientist at ESA.

The spacecraft’s sensitive cameras captured an incredible number of objects in great detail. Zooming very deep into the mosaic (this image is enlarged 600 times compared to the full view), we can still clearly see the intricate structure of a spiral galaxy.

More:
https://www.esa.int/Science_Exploration/Space_Science/Euclid/Zoom_into_the_first_page_of_ESA_Euclid_s_great_cosmic_atlas#msdynmkt_trackingcontext=259377f3-5b40-4c93-a6ad-c998da6b5832

Had the chance of attending the premiere at the IAC in Milan last night. The first strong gravitational lensing observations by Euclid were teased to a small audience at the ESA exhibition booth a couple of hours earlier as a sneak peek of the rest of the results to be presented in the auditorium... but boy were we unprepared for the stunning, wide, deep fields that would then come.

The full Moon could be inscribed inside the "square" to the rightmost side of the mosaic. The Hubble Extreme Deep Field takes up about the apparent angular size of Mare Nectaris on the Moon. You can see in the above article and animation how much one can zoom into Euclid's; I gather the XDF size would be somewhere between the 36x and 150x sizes. Only we have hundreds if not thousands of such deep fields now. In any case, and regardless of how it compares with previous surveys, what was truly unique was the sheer emotion of appreciating what the video portrayed, in the huge venue screen with IMAX-like thundering music. You really viscerally felt the size, even though of course it's just a dulled, toned-down version of the real thing (it was estimated 16500 TV screens would be needed to show the actual image in full resolution).

I can tell you the audience was shaken, and teared up. I was one of them.

[AndrewM]

https://www.esa.int/Science_Exploration/Space_Science/Euclid/Euclid_discovers_a_stunning_Einstein_ring [Feb 10]

Here is a snip from the article as it is rather long. The full findings are published in Astronomy & Astrophysics Vol. 694 Article A145.

The Einstein Ring, an extremely rare phenomenon, turned out to be hiding in plain sight in a galaxy not far away. The galaxy, called NGC 6505, is around 590 million light-years from Earth, a stone’s throw away in cosmic terms. But this is the first time that the ring of light surrounding its centre is detected, thanks to Euclid’s high-resolution instruments

The ring around the foreground galaxy is made up of light from a farther out bright galaxy. This background galaxy is 4.42 billion light-years away, and its light has been distorted by gravity on its way to us. The far-away galaxy hasn’t been observed before and doesn’t yet have a name.

“An Einstein ring is an example of strong gravitational lensing,” explains Conor O’Riordan, of the Max Planck Institute for Astrophysics, Germany, and lead author of the first scientific paper analysing the ring. “All strong lenses are special, because they're so rare, and they're incredibly useful scientifically. This one is particularly special, because it’s so close to Earth and the alignment makes it very beautiful.”

[AndrewM]

The first batch of survey data was released on March 19th. The next major release is in October 2026.

https://www.esa.int/Science_Exploration/Space_Science/Euclid/Euclid_opens_data_treasure_trove_offers_glimpse_of_deep_fields [March 19]

On 19 March 2025, the European Space Agency’s Euclid mission released its first batch of survey data, including a preview of its deep fields. Here, hundreds of thousands of galaxies in different shapes and sizes take centre stage and show a glimpse of their large-scale organisation in the cosmic web.

Covering a huge area of the sky in three mosaics, the data release also includes numerous galaxy clusters, active galactic nuclei and transient phenomena, as well as the first classification survey of more than 380 000 galaxies and 500 gravitational lens candidates compiled through combined artificial intelligence and citizen science efforts. All of this sets the scene for the broad range of topics that the dark Universe detective Euclid is set to address with its rich dataset.

“Euclid shows itself once again to be the ultimate discovery machine. It is surveying galaxies on the grandest scale, enabling us to explore our cosmic history and the invisible forces shaping our Universe,” says ESA’s Director of Science, Prof. Carole Mundell.

“With the release of the first data from Euclid’s survey, we are unlocking a treasure trove of information for scientists to dive into and tackle some of the most intriguing questions in modern science. With this, ESA is delivering on its commitment to enable scientific progress for generations to come.”

As of 19 March 2025, Euclid has observed about 2000 square degrees, approximately 14% of the total survey area (14 000 square degrees). The three deep fields together comprise 63.1 square degrees.

Euclid ‘quick’ releases, such as the one of 19 March, are of selected areas, intended to demonstrate the data products to be expected in the major data releases that follow, and to allow scientists to sharpen their data analysis tools in preparation. The mission’s first cosmology data will be released to the community in October 2026. Data accumulated over additional, multiple passes of the deep field locations will be included in the 2026 release.

The three deep field previews can now be explored in ESASky from 19 March 12:00 CET onwards:

Euclid Deep Field South
Euclid Deep Field Fornax
Euclid Deep Field North
The data release of 19 March 2025 is described in multiple scientific papers which have not yet been through the peer-review process, but which will be submitted to the journal Astronomy & Astrophysics. A preprint of the papers is available here from 19 March 12:00 CET.

Find more detailed information about the data release here.

[jacqmans]

Euclid peers through a dark cloud’s dusty veil
05/11/2025

This shimmering view of interstellar gas and dust was captured by the European Space Agency’s Euclid space telescope. The nebula is part of a so-called dark cloud, named LDN 1641. It sits at about 1300 light-years from Earth, within a sprawling complex of dusty gas clouds where stars are being formed, in the constellation of Orion.

In visible light this region of the sky appears mostly dark, with few stars dotting what seems to be a primarily empty background. But, by imaging the cloud with the infrared eyes of its NISP instrument, Euclid reveals a multitude of stars shining through a tapestry of dust and gas.

This is because dust grains block visible light from stars behind them very efficiently but are much less effective at dimming near-infrared light.

The nebula is teeming with very young stars. Some of the objects embedded in the dusty surroundings spew out material – a sign of stars being formed. The outflows appear as magenta-coloured spots and coils when zooming into the image.

In the upper left, obstruction by dust diminishes and the view opens toward the more distant Universe with many galaxies lurking beyond the stars of our own galaxy.

Euclid observed this region of the sky in September 2023 to fine-tune its pointing ability. For the guiding tests, the operations team required a field of view where only a few stars would be detectable in visible light; this portion of LDN 1641 proved to be the most suitable area of the sky accessible to Euclid at the time.

The tests were successful and helped ensure that Euclid could point reliably and very precisely in the desired direction. This ability is key to delivering extremely sharp astronomical images of large patches of sky, at a fast pace. The data for this image, which is about 0.64 square degrees in size – or more than three times the area of the full Moon on the sky – were collected in just under five hours of observations.

Euclid is surveying the sky to create the most extensive 3D map of the extragalactic Universe ever made. Its main objective is to enable scientists to pin down the mysterious nature of dark matter and dark energy.

Yet the mission will also deliver a trove of observations of interesting regions in our galaxy, like this one, as well as countless detailed images of other galaxies, offering new avenues of investigation in many different fields of astronomy.

[Technical details: The colour image was created from NISP observations in the Y-, J- and H-bands, rendered blue, green and red, respectively. The size of the image is 11 232 x 12 576 pixels. The jagged boundary is due to the gaps in the array of NISP’s sixteen detectors, and the way the observations were taken with small spatial offsets and rotations to create the whole image. This is a common effect in astronomical wide-field images.]

[Image description: The focus of the image is a portion of LDN 1641, an interstellar nebula in the constellation of Orion. In this view, a deep-black background is sprinkled with a multitude of dots (stars) of different sizes and shades of bright white. Across the sea of stars, a web of fuzzy tendrils and ribbons in varying shades of orange and brown rises from the bottom of the image towards the top-right like thin coils of smoke.]

[jacqmans]

Euclid’s galaxy garland
22/12/2025

Galaxy NGC 646 sparkles like a cosmic holiday garland in this new image from the European Space Agency’s Euclid space telescope.

This large barred spiral galaxy is located in the constellation Hydrus and was discovered in 1834 by the British astronomer John Herschel (the son of William Herschel). The galaxy is moving away from us at about 8145 km per second. It's located roughly 392 million light-years from Earth, which means its light takes hundreds of millions of years to reach us.

Although this sounds very far, NGC 646 is actually quite close compared to the billions of galaxies that Euclid will observe during its six-year mission.

By the end of 2026, ESA and the Euclid Consortium will release the first year of observations, covering about 1900 square degrees of the sky (approximately 14% of the total survey area). These images will reveal hundreds of thousands of galaxies in exquisite detail, offering new insights into how galaxies form and evolve – and why barred galaxies become more common as the Universe ages.

In this image, NGC 646 appears close to a smaller galaxy to the left, called PGC 6014. They look like neighbours, but they’re actually about 45 million light-years apart, with PGC 6014 at a distance of 347 million light-years from us. So, any gravitational interaction between them, if it exists, would be very weak and short-lived.

[Image description: An image of space made by the Euclid telescope shows a bright barred spiral galaxy with two sweeping arms glowing in shades of blue and white against a deep black background dotted with stars. Its core is luminous. Its spiral arms curve gracefully outward to the left and down to the right, resembling a cosmic garland draped across the scene. A smaller, faint and round galaxy appears to the left of the barred spiral galaxy.]

[JulesVerneATV]

object is a Reionization-Limited H I Cloud, or "RELHIC.” The term “H I” refers to neutral hydrogen, and “RELHIC”

not exactly fringe exotic 'New Physics' but a few suspected billions of solar masses worth of dark matter could be around Galaxy-Remnants

NASA/ESA Hubble Space Telescope team uncovered a new type of astronomical object

A team using Hubble Space Telescope has announced the discovery of a completely new celestial object in the universe, titled "Cloud-9".

https://www.esa.int/Science_Exploration/Space_Science/Cloud-9_a_new_celestial_object_found_by_Hubble#msdynmkt_trackingcontext=33cc9b07-474b-4edf-b94c-8760ade60100


Mysterious space object is full of dark matter

https://www.popsci.com/science/new-space-object-cloud-9/


in the vicinity of the spiral galaxy M94, in the constellation Canes Venatici.
https://www.skyatnightmagazine.com/apple-news/starless-dark-matter-galaxy-cloud-9


Starless ‘Failed Galaxy’ Is First of Its Kind Ever Seen

https://www.scientificamerican.com/article/starless-cloud-9-is-an-entirely-new-astrophysical-object/