Dark Matter Telescope Captures a Sparkling Galaxy Merger

The Euclid Space Telescope is decking the halls with boughs of starlight

By Meghan Bartels edited by Claire Cameron

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. — ESA/Euclid/Euclid Consortium/NASA, *image processing:* Euclid Science Ground Segment and M. Schirmer (MPIA) (CC BY-SA 3.0 IGO)

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A languid spiral galaxy appears draped against deep space in a stunning new image from the European Space Agency’s Euclid telescope.

Euclid launched in 2023 on a six-year mission to map the cosmos at scale, observing billions of galaxies stretching as far away as 10 billion light-years from Earth. The effort could reveal how galaxies form and evolve and how the universe has expanded over its 13.8-billion-or-so-year history.

In turn, astronomers hope Euclid will shed light on dark matter, which we know tugs at normal matter but is utterly invisible to us, and dark energy, the force that is responsible for accelerating the speed at which the universe expands.

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That effort will begin in earnest next year, when Euclid releases its first formal batch of data, which will account for about 14 percent of its final survey area.

Until then, the Euclid team has offered the occasional teaser for the telescope’s power, including a festive new image of the galaxy NGC 646. This elegant spiral galaxy, filled with stars, is about 392 million light-years away from Earth—some 4 percent of the distance of Euclid’s farthest targets—and is retreating at more than 5,000 miles per second.

Appearing at the left tip of NGC 646 is a second galaxy, known as PGC 6014—but their apparent closeness is merely an optical illusion; in truth, PGC 6014 is nearly 45 million light-years closer to Earth.

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