The European Space Agency's (ESA) new dark matter-hunting telescope Euclid has an incredible task: to observe and measure the shape, distances, and motion of billions of galaxies up to 10 billion light-years from us. Once put together, it will be the largest three-dimensional map of the universe ever made, and will help astronomers answer crucial questions about the nature of dark matter and dark energy.
The telescope was launched into space in July and despite some teething issues, it is now ready to reveal just how revolutionary it will be as an instrument. The Euclid Consortium has selected five images that show off the potential that this dark universe observatory has.
Unsurprisingly, the first image released is a cluster of galaxies, the bread and butter of what will be Euclid's scientific focus. The Perseus cluster is one of the most massive known groups of galaxies with about 1,000 members located roughly 240 million light-years away. It is also the object that produces the lowest note in the universe. This image not only shows all those galaxies but it also shows 100,000 more stretching out to 10 billion light-years away. Many of those faint distant galaxies are completely new to science.
Euclid observes the universe in visible light and infrared, bringing a level of detail and clarity in a single observation that is unprecedented. The view of spiral galaxy IC 342 or local irregular galaxy NGC 6822 shows just how sharp its eye on the sky really is.
“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,” René Laureijs, ESA’s Euclid Project Scientist, said in a statement sent to IFLScience.
But Euclid is not just about distant galaxies and the biggest mysteries in cosmology, it's a versatile instrument. It's the first telescope that can see a whole globular cluster – a spherical collection of stars bound by gravity – in a single observation while distinguishing every star in it, like in the case of NGC 6397 below, the second closest globular cluster to Earth at just 7,800 light-years away.
It can also hunt for gas giant planets, brown dwarfs, and baby stars around nebulae – objects that would be too dim for many other observatories should be visible to Euclid. And at the very least, we will get breathtaking new views of these stellar nurseries like the Horsehead Nebula (below).
“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,” added Giuseppe Racca, ESA’s Euclid Project Manager.
The images are not just beautiful, they are full of science that is being worked on as we speak. The consortium expects many papers to come from just these five images, and a huge array of new observations are in the works as well, shining a light into the dark universe.
“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,” explained 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.”