The European Space Agency’s (ESA) satellite Euclid completed the first part of its long journey into space when it arrived in Florida by boat from Italy on May 1, 2023. This article was originally published on: Speech. The publication contributed an article to Space.com’s Expert Voices: Op-Ed & Insights.

The European Space Agency’s (ESA) satellite Euclid completed the first part of its long journey into space when it arrived in Florida by boat from Italy on May 1, 2023. It will launch on a SpaceX Falcon 9 rocket from Cape Canaveral in early July.

Euclid was created to help us better understand the “mysterious” components of our universe known as dark matter and dark energy. Unlike the normal matter we experience here on Earth, dark matter neither reflects nor emits light. It connects galaxies and is believed to make up about 80% of the entire mass of the universe. We have known about him for a century, but his true nature remains a mystery.

Dark energy is just as confusing. Astronomers have shown that the expansion of the universe over the past five billion years has been faster than expected. Many believe this acceleration is due to an invisible force called dark energy. This accounts for about 70% of the energy in the universe. Euclid would map this “dark universe” using a range of scientific tools to shed light on various aspects of dark energy and dark matter.

Light in the Dark

After launch, Euclid will travel to a region of space called the second Earth-Sun Lagrangian point, which is five times farther from us than the Moon. This is where the gravitational pull of the Sun and Earth is balanced, giving Euclid a fixed perspective from which to observe the universe. At this point Euclid will join the James Webb Space Telescope (JWST) and will be the perfect companion for this magnificent space observatory.

My relationship with Euclid began in 2007 when ESA invited me to join an independent conceptual advisory group to consider two competing assignment proposals, SPACE and DUNE.

Both used different methods and therefore different tools to study the dark universe, and ESA sought to separate the two. Both concepts were convincing and our team agreed that both had merits, especially in providing significant cross validation between the two. Thus Euclid was born from the best of both concepts.

Euclid was designed to study the entire universe, so he needs tools with a wide field of view. The wider the field of view of an imaging device, the more it can observe the universe. To do this, Euclid uses a relatively small telescope compared to the JWST. In size, the Euclid is roughly the size of a truck compared to the airplane-sized JWST. But Euclid also has some of the largest digital cameras in space, with fields of view hundreds of times larger than JWSTs.

Shapes and colors

Built primarily in the UK, the Euclidean VIS (or visible) instrument is designed to measure the positions and shapes of as many galaxies as possible to find subtle correlations in this data that originates from the gravitational lens of light as it moves towards us. through interspersed dark matter. This gravitational lensing effect is weak, only a fraction of a hundred thousandth for most galaxies, so many galaxies are required to view the effect in high resolution. Thus, VIS will produce Hubble-like image quality over more than a third of the night sky.

However, VIS cannot measure the colors of objects. When light from these objects is shifted to a longer or redder wavelength relative to their distance from us, this is necessary to measure their distance using the redshift effect. Some of this data will need to be obtained from existing and planned ground-based observatories, but Euclid also has a specially designed NISP (Near Infrared Spectrometer and Photometer) instrument to measure infrared colors and spectra and therefore redshifts. The farthest galaxy Euclid would ever see.

To measure dark energy, NISP will use a relatively new technique called Baryon Acoustic Oscillation (BAO), which provides a precise measurement of the universe’s expansion history over the last 10 billion years. This date is vital for testing possible dark energy models, including proposed changes to Einstein’s general theory of relativity.

Treasure

Such an experiment would require an army of scientists, and not all of them work solely on dark matter and dark energy. Like the JWST, Euclid will be a treasure trove of new discoveries in many fields of astronomy. The Euclidean consortium needs hundreds of people to help develop the complex software needed to combine space-based data with ground-based data to produce the high-precision shapes and colors of billions of galaxies.

This software has also been tested and tested using some of the largest universe simulations ever created. Upon arrival at L2, Euclid will undergo several months of testing, verification and calibration to ensure that the instruments and telescope are working properly. We’re all familiar with this nervous anticipation after JWST’s recent launch.

When Euclid is ready, he will begin a five-year survey of 15,000 square degrees of the sky, with nearly 2,000 scientists from around the world collecting the results. But Euclid’s true power can only be understood when we gather all this data together and carefully analyze it. It may take another five years before we get definitive dark answers, leading us into the next decade. So the SpaceX launch seems like only half of Euclid’s story.

I’m going to Florida this summer to see the launch of Euclid. Hundreds of colleagues who have dedicated their careers to building and experimenting with this wonderful telescope will join me. Seeing the project come together like this makes me proud to call myself “Euclid”.