posted 06-30-2023 09:25 AM               

Euclid: Exploring the Dark Universe

ESA's Euclid mission is designed to map the large-scale structure of the Universe and help us to understand two mysterious components: dark matter and dark energy.

Above: The Euclid space telescope is encapsulated inside the Falcon 9 payload fairing. (SpaceX)

For centuries, astronomers have aimed to learn more about the luminous sources of the cosmos, that is, planets, stars, galaxies and gas, for example. But these objects make up only a small fraction of what the Universe contains.

95% of the Universe appears to be made up of unknown 'dark' matter and energy. Dark matter and energy affect the motion and distribution of visible sources, but do not emit or absorb any light, and scientists do not know yet what these entities actually are. Understanding their nature is therefore one of the most compelling challenges of cosmology and fundamental physics today.

Euclid will create the largest, most accurate 3D map of the Universe. It will observe billions of galaxies out to 10 billion light-years, across more than one third of the sky.

With this map, Euclid will reveal how the Universe has expanded and how large-scale structure has evolved over cosmic history. And from this we can learn more about the role of gravity and the nature of dark energy and dark matter.

Beyond launch day

A SpaceX Falcon 9 rocket will launch the ESA Euclid mission from Space Launch Complex 40 (SLC-40) at Cape Canaveral Space Force Station in Florida.

After launch, Euclid sets sail for the Sun-Earth Lagrange point L2. Four weeks after launch, Euclid will enter in orbit around this point, which is located at 1.5 million kilometres from Earth, in the opposite direction from the Sun.

Once in orbit, mission operators start verifying all the functions of the telescope. During this, residual water is outgassed and subsequently Euclid’s instruments will be turned on. Between one and three months after launch, Euclid will go through several calibrations and scientific performance tests and get ready for science.

The telescope begins its early phase of the survey of the Universe three months after launch.

posted 07-01-2023 08:07 AM               

SpaceX is targeting Saturday, July 1 for Falcon 9’s launch of the ESA Euclid mission. Liftoff is targeted for 11:12 a.m. ET (15:12 UTC).

The live webcast of this mission will begin about 15 minutes prior to liftoff.

posted 07-01-2023 11:23 AM               

ESA's Euclid lifts off on quest to unravel the cosmic mystery of dark matter and dark energy

ESA's Euclid spacecraft lifted off on a SpaceX Falcon 9 rocket from Cape Canaveral Space Force Station in Florida, USA, at 17:12 CEST on 1 July. The successful launch marks the beginning of an ambitious mission to uncover the nature of two mysterious components of our Universe: dark matter and dark energy, and to help us answer the fundamental question: what is the Universe made of?

Following launch and separation from the rocket, ESA's European Space Operations Centre (ESOC) in Darmstadt, Germany, confirmed acquisition of signal from Euclid via the New Norcia ground station in Australia at 17:57 CEST. 

"The successful launch of Euclid marks the beginning of a new scientific endeavour to help us answer one of the most compelling questions of modern science," says ESA Director General Josef Aschbacher. "Euclid has been made possible by ESA's leadership, the effort and expertise of hundreds of European industrial and scientific institutions, and through collaboration with international partners. The quest to answer fundamental questions about our cosmos is what makes us human. And, often, it is what drives the progress of science and the development of powerful, far-reaching, new technologies. ESA is committed to expanding Europe's ambitions and successes in space for future generations."

"The Euclid mission is the result of the passion and expertise of those who contributed to designing and building this sophisticated space telescope, the competence of our flight operations team, and the inquiring spirit of the science community," says Giuseppe Racca, ESA's Euclid Project Manager. "There have been many challenges during the project, but we have worked hard and now we have successfully reached this launch milestone together with our partners in the Euclid Consortium and NASA."

The Euclid Consortium contributed the two highly advanced scientific instruments – the visible-wavelength camera (VIS) and the Near-Infrared Spectrometer and Photometer (NISP). NASA provided the detectors for NISP.

Exploring the dark Universe

Euclid will observe billions of galaxies out to 10 billion light-years to create the largest, most accurate 3D map of the Universe, with the third dimension representing time itself. This detailed chart of the shape, position and movement of galaxies will reveal how matter is distributed across immense distances and how the expansion of the Universe has evolved over cosmic history, enabling astronomers to infer the properties of dark energy and dark matter. This will help theorists to improve our understanding of the role of gravity and pin down the nature of these enigmatic entities.

"Today we celebrate the successful launch of a ground-breaking mission that places Europe at the forefront of cosmological studies," says Carole Mundell, ESA's Director of Science. "If we want to understand the Universe we live in, we need to uncover the nature of dark matter and dark energy and understand the role they played in shaping our cosmos. To address these fundamental questions, Euclid will deliver the most detailed map of the extra-galactic sky. This inestimable wealth of data will also enable the scientific community to investigate many other aspects of astronomy, for many years to come."

To achieve its ambitious scientific goal, Euclid is equipped with a 1.2 m reflecting telescope that feeds the two innovative scientific instruments: VIS, which takes very sharp images of galaxies over a large fraction of the sky, and NISP, which can analyse galaxies' infrared light by wavelength to accurately establish their distance.

The spacecraft and communications will be controlled from ESOC. To cope with the vast amounts of data Euclid will acquire, ESA's Estrack network of deep space antennas has been upgraded. These data will be analysed by the Euclid Consortium – a group of more than 2000 scientists from more than 300 institutes across Europe, the US, Canada and Japan.

As the mission progresses, Euclid's treasure trove of data will be released with yearly cadence and will be accessible to the global scientific community via the Science Archive hosted at ESA's European Space Astronomy Centre in Spain.

"This is a great moment for science, one that we have long been looking forward to: the launch of Euclid, on a mission to decipher the puzzle of dark matter and dark energy," says René Laureijs, ESA's Euclid Project Scientist. "The big mystery of the fundamental constituents of the Universe is staring us in the face, offering a formidable challenge. Thanks to its advanced telescope and powerful scientific instrumentation, Euclid is poised to help us unravel this mystery."

Journey to Lagrange point 2

In the next four weeks, Euclid will travel towards Sun-Earth Lagrange point 2, an equilibrium point of the Sun-Earth system located 1.5 million km from Earth (about four times the Earth-Moon distance) in the direction opposite from the Sun. There, Euclid will be manoeuvred into orbit around this point and mission controllers will start the activities to verify all the functions of the spacecraft, check out the telescope and finally turn on the scientific instruments.

Scientists and engineers will then be engaged in an intense two-month phase of testing and calibrating Euclid's scientific instruments and preparing for routine observations. Over six years Euclid will survey one third of the sky with unprecedented accuracy and sensitivity.

About Euclid

Euclid is a European mission, built and operated by ESA, with contributions from NASA. The Euclid Consortium is responsible for providing the scientific instruments and scientific data analysis. ESA selected Thales Alenia Space as prime contractor for the construction of the satellite and its service module, with Airbus Defence and Space chosen to develop the payload module, including the telescope. NASA provided the detectors of the Near-Infrared Spectrometer and Photometer, NISP. Euclid is a medium-class mission in ESA's Cosmic Vision Programme.

posted 11-08-2023 08:38 AM               

Euclid's first images: the dazzling edge of darkness

ESA’s Euclid space mission reveals its first full-colour images of the cosmos. Never before has a telescope been able to create such razor-sharp astronomical images across such a large patch of the sky, and looking so far into the distant Universe. These five images illustrate Euclid's full potential; they show that the telescope is ready to create the most extensive 3D map of the Universe yet, to uncover some of its hidden secrets.

Euclid, our dark Universe detective, has a difficult task: to investigate how dark matter and dark energy have made our Universe look like it does today. 95% of our cosmos appears to be made of these mysterious ‘dark’ entities. But we don’t understand what they are because their presence causes only very subtle changes in the appearance and motions of the things we can see.

To reveal the ‘dark’ influence on the visible Universe, over the next six years Euclid will observe the shapes, distances and motions of billions of galaxies out to 10 billion light-years. By doing this, it will create the largest cosmic 3D map ever made.

What makes Euclid’s view of the cosmos special is its ability to create a remarkably sharp visible and infrared image across a huge part of the sky in just one sitting.

The images released today (Nov. 7) showcase this special capacity: from bright stars to faint galaxies, the observations show the entirety of these celestial objects, while remaining extremely sharp, even when zooming in on distant galaxies.

“Dark matter pulls galaxies together and causes them to spin more rapidly than visible matter alone can account for; dark energy is driving the accelerated expansion of the Universe. Euclid will for the first-time allow cosmologists to study these competing dark mysteries together,” explains ESA Director of Science, Professor Carole Mundell. “Euclid will make a leap in our understanding of the cosmos as a whole, and these exquisite Euclid images show that the mission is ready to help answer one of the greatest mysteries of modern physics.”

“We have never seen astronomical images like this before, containing so much detail. They are even more beautiful and sharp than we could have hoped for, showing us many previously unseen features in well-known areas of the nearby Universe. Now we are ready to observe billions of galaxies, and study their evolution over cosmic time,” says René Laureijs, ESA’s Euclid Project Scientist.

“Our high standards for this telescope paid off: that there is so much detail in these images, is all thanks to a special optical design, perfect manufacturing and assembly of telescope and instruments, and extremely accurate pointing and temperature control,” adds Giuseppe Racca, ESA’s Euclid Project Manager.

“I wish to congratulate and thank everyone involved with making this ambitious mission a reality, which is a reflection of European excellence and international collaboration. The first images captured by Euclid are awe-inspiring and remind us of why it is essential that we go to space to learn more about the mysteries of the Universe,” says ESA Director General Josef Aschbacher.

Zoom into the Universe through Euclid’s eyes

The Perseus Cluster of galaxies

This incredible snapshot from Euclid is a revolution for astronomy. The image shows 1000 galaxies belonging to the Perseus Cluster, and more than 100 000 additional galaxies further away in the background.

Many of these faint galaxies were previously unseen. Some of them are so distant that their light has taken 10 billion years to reach us. By mapping the distribution and shapes of these galaxies, cosmologists will be able to find out more about how dark matter shaped the Universe that we see today.

This is the first time that such a large image has allowed us to capture so many Perseus galaxies in such a high level of detail. Perseus is one of the most massive structures known in the Universe, located ‘just’ 240 million light-years away from Earth.

Astronomers demonstrated that galaxy clusters like Perseus can only have formed if dark matter is present in the Universe. Euclid will observe numerous galaxy clusters like Perseus across cosmic time, revealing the ‘dark’ element that holds them together.

Spiral galaxy IC 342

Over its lifetime, our dark Universe detective will image billions of galaxies, revealing the unseen influence that dark matter and dark energy have on them. That’s why it’s fitting that one of the first galaxies that Euclid observed is nicknamed the ‘Hidden Galaxy’, also known as IC 342 or Caldwell 5. Thanks to its infrared view, Euclid has already uncovered crucial information about the stars in this galaxy, which is a look-alike of our Milky Way.

Irregular galaxy NGC 6822

To create a 3D map of the Universe, Euclid will observe the light from galaxies out to 10 billion light-years. Most galaxies in the early Universe don’t look like the quintessential neat spiral, but are irregular and small. They are the building blocks for bigger galaxies like our own, and we can still find some of these galaxies relatively close to us. This first irregular dwarf galaxy that Euclid observed is called NGC 6822 and is located close by, just 1.6 million light-years from Earth.

Globular cluster NGC 6397

This sparkly image shows Euclid’s view on a globular cluster called NGC 6397. This is the second-closest globular cluster to Earth, located about 7800 light-years away. Globular clusters are collections of hundreds of thousands of stars held together by gravity. Currently no other telescope than Euclid can observe an entire globular cluster in one single observation, and at the same time distinguish so many stars in the cluster. These faint stars tell us about the history of the Milky Way and where dark matter is located.

The Horsehead Nebula

Euclid shows us a spectacularly panoramic and detailed view of the Horsehead Nebula, also known as Barnard 33 and part of the constellation Orion. In Euclid’s new observation of this stellar nursery, scientists hope to find many dim and previously unseen Jupiter-mass planets in their celestial infancy, as well as young brown dwarfs and baby stars.

New discoveries, soon

Euclid’s first view of the cosmos is not only beautiful, but also immensely valuable for the scientific community.

Firstly, it showcases that Euclid’s telescope and instruments are performing extremely well and that astronomers can use Euclid to study the distribution of matter in the Universe and its evolution at the largest scales. Combining many observations of this quality covering large areas of the sky will show us the dark and hidden parts of the cosmos.

Secondly, each image individually contains a wealth of new information about the nearby Universe (click on the individual images to learn more about this). “In the coming months, scientists in the Euclid Consortium will analyse these images and publish a series of scientific papers in the journal Astronomy & Astrophysics, together with papers about the scientific objectives of the Euclid mission and the instrument performance,” adds Yannick Mellier, Euclid Consortium lead.

And finally, these images take us beyond the realm of dark matter and dark energy, also showing how Euclid will create a treasure trove of information about the physics of individual stars and galaxies.

Getting ready for routine observations

Euclid launched to the Sun-Earth Lagrange point 2 on a SpaceX Falcon 9 rocket from Cape Canaveral Space Force Station in Florida, USA, at 17:12 CEST on 1 July 2023. In the months after launch, scientists and engineers have been engaged in an intense phase of testing and calibrating Euclid’s scientific instruments. The team is doing the last fine-tuning of the spacecraft before routine science observations begin in early 2024.

Over six years, Euclid will survey one third of the sky with unprecedented accuracy and sensitivity. As the mission progresses, Euclid’s bank of data will be released once per year, and will be available to the global scientific community via the Astronomy Science Archives hosted at ESA’s European Space Astronomy Centre in Spain.