What is your reaction to these images and why are they significant?

The view they show of these objects is strikingly different from what other observatories, in particular Hubble and James Webb Space Telescope (JWST), show, for a few reasons.

First of all, JWST and Hubble offer deeper, higher-resolution views, with JWST specifically being an infrared telescope, whereas Hubble and Euclid primarily operate in the optical and near infrared. Euclid was built with a very wide-angle camera, so it gives you a unique view. With any of these images, download them at maximum resolution, starting at the widest possible view, then pick four or five regions and zoom in step by step. What you get when you do this is really powerful. You see the broader picture (on a much wider scale than Hubble or JWST can offer), and then you zoom in and get the high-resolution view at close to Hubble’s or JWST’s resolution, but not its depth, as Euclid tends to concentrate on that wide-angle view.

Second, each image shows some amazing things about the objects they capture. Whether you’re talking about the image of M78 – a star formation region in our own galaxy – where you see the distribution of gas and newly born stars on a scale we’ve never seen before, or NGC 6744 – a fairly typical, massive spiral galaxy that isn’t too different from our own – where we get a glimpse of the galaxy that is both wide and deep in a way we’ve never done before. Or take the clusters Abell 2390 and Abell 2764, where we see an enormous number of galaxies, both in the cluster center and behind it, as well as in the clusters’ outskirts.

Finally, the combination of the wide-angle lens and Euclid’s close-up view allows you to see both the large-scale distribution of matter as well as the fine details. In the case of an object in our own galaxy, like M78, we see a fascinating large-scale structure, with huge amounts of gas and stars and lots of clumps and filaments of gas. But then zoom in and you see amazing detail – new stars being born, lighting up the gas and clearing it out to reveal other stars nearby, filaments within filaments. The detail is just amazing.

Or take the Abell 2764 cluster image, where they picked a region where the cluster center is off in one corner. This allows you to see not only the cluster center and outskirts, lots of galaxies in each region of the cluster, the arcs and distorted shapes of the galaxies behind, who have their light bent by gravity, but other things. Move over to the bright star in the lower left-hand part of the image, and you see not only the star, but also a gravitationally lensed arc, and lots of galaxies underneath it. You can do this with each of the images, and it’s just really powerful.