Imagine holding a wine glass up to a candle (of course I had to pour a glass to try this.) The curved glass bends and distorts the flame, stretching it into arcs and rings of light.

Now scale that up to the size of a galaxy, replace the glass with a trillion solar masses of matter, and the candle with an entire galaxy billions of light years away.

What you get is one of the most beautiful and scientifically powerful phenomena in all of astronomy, a gravitational lens.

Diagram illustrating gravitational lensing.
Gravitational lensing is used by astronomers to study very distant and very faint galaxies. Note that the scale has been greatly exaggerated in this diagram. In reality, the distant galaxy is much further away and much smaller. (NASA, ESA & L. Calçada)

Einstein’s general theory of relativity tells us that mass warps the fabric of space itself. Light, following that curved space, bends around massive objects like galaxies and galaxy clusters.

When the alignment is just right, the result is extraordinary, background galaxies appear stretched into glowing arcs, or smeared into perfect rings known as Einstein rings.

These are not tricks of the eye.

They are the Universe bending light around corners.

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Now the European Space Agency’s Euclid telescope that has already transforming our understanding of the Universe, has released a new dataset of unprecedented scale, and scientists need help searching it.

The Space Warps citizen science project, hosted on the Zooniverse platform, is inviting members of the public to join professional astronomers in hunting for gravitational lenses hidden within Euclid’s first full year of observations.

I have a soft spot for citizen science. My first experience of it was SETI@home, a project that let people donate their computer’s idle time to help search for signals from extraterrestrial intelligence.

A collage of fourteen by eight squares containing examples of gravitational lenses. Each example typically comprises a bright centre with smears of stars in an arc or multiple arcs around it as a result of light travelling towards Euclid from distant galaxies being bent and distorted by normal and dark matter in the foreground. In some rare cases the smearing is in a complete ring, creating a so-called Einstein Ring.
Mosaic of strong gravitational lenses discovered in the first Space Warps campaign in 2024. (ESA/Euclid/Euclid Consortium/NASA, image processing by M. Walmsley, M. Huertas-Company, J.-C. Cuillandre)

It ran as a screensaver on my desktop, and the idea that my machine might be the one to detect an alien civilisation while I made a cup of tea felt genuinely thrilling.

That project showed the world what distributed human effort could achieve. Space Warps carries the same spirit but this time, the target is gravitational lenses rather than little green men.

Euclid has surveyed roughly 72 million galaxies in this data release, around 30 times larger than its initial dataset.

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Artificial intelligence has already pre-selected around 300,000 candidate images for closer inspection, but the human eye remains uniquely good at spotting the subtle, irregular arcs that signal a gravitational lens.

Scientists hope to find more than 10,000 new lenses from this search alone, which is more than have been discovered in the entire history of astronomy.

When the team analyzed just 0.04 percent of the available data, they found 500 lenses, most of them never seen before.

Against a dark blue background, this infographic contains a paragraph of text in the top left corner, the logo of ESA in the top right corner and a succession of graphics in the bottom half of the image. The text paragraph explains the principle behind Einstein rings, and it can be read in the image caption. The graphics below it illustrate this astrophysical phenomenon, and by looking at them from left to right we can understand the process of how Einstein rings are formed.The left-most element in the bottom half of the image is a graphic representation of a galaxy, labelled 'distant galaxy'. To the right of it, another galaxy is shown, labelled 'Foreground galaxy acting as a magnifying lens'. The third illustration, to the right of the previous one, shows ESA's Euclid space telescope and is labelled 'Telescope'. The 'distant galaxy' and the 'Telescope' are connected by two lines that form an elongated diamond-shape around the 'Foreground galaxy'. This line is labelled 'Gravity bends the light rays of the distant galaxy'. The fourth and last illustration in the line shows a ring of light around a central disk and is labelled 'What the telescope sees'.
When we observe a distant galaxy with our telescope, its light may encounter another galaxy on its way to us. That galaxy acts like a magnifying lens, bending the light rays as they travel due to its gravity. If the background galaxy, the lensing galaxy, and the telescope are perfectly aligned, the image appears as a ring. Einstein rings were first theorized to exist by Einstein in his general theory of relativity. (ESA)

Gravitational lenses act as natural weighing scales for galaxies, measuring the total mass of everything they contain including the dark matter that neither emits nor reflects light.

Related: Our Galaxy Floats Inside a ‘Pancake’ Made of Dark Matter, Astronomers Discover

By cataloguing thousands of these systems across different distances and epochs, scientists can trace how structures grew and how dark energy has driven the accelerating expansion of the Universe.

You don’t need a telescope or a physics degree to take part. Just a curiosity about the Universe and a willingness to look.

To learn more about the project, click here.

This article was originally published by Universe Today. Read the original article.