Hubble Snaps Stunning Image Of An Ancient Galaxy Cluster Roughly 7 Billion Light-Years Away

ESA/Hubble & NASA, I. Karachentsev et al., F. High et al.

In the 29 years since it’s been scouring the skies to investigate the mysteries of the deep cosmos, the Hubble Space Telescope has beamed back a vast collection of mind-blowing photos, unraveling some of the most beautiful structures in the universe.

Over the years, the venerable spacecraft has treated scientists and space enthusiasts to awe-inspiring pics of distant star clusters, swirling nebulae, dazzling supernovae, and far-flung galaxies. Those eager to look back on some of these extraordinary images can check out a list of Hubble’s top 100 most iconic photos, as compiled by the European Space Agency (ESA).

In keeping with Hubble’s rich tradition of mesmerizing space images, its latest snapshot leaves nothing to be desired. For its most recent photo, the space telescope cast its inquisitive eyes deep into the cosmos, peering back through time billions of years ago to an age when our sun wasn’t even born yet. Unveiled by NASA on Friday, the glorious snapshot portrays an entire cluster of faraway galaxies, collectively known as SPT-CL J0615-5746 – or SPT0615, for short. Nestled in the southern sky, deep within the constellation of Pictor (“the Painter’s Easel”), this particular galaxy cluster is as ancient as it is beautiful.

This massive structure lies at a staggering distance from Earth and is so remote that it took roughly 7 billion light-years for its light to travel to us. In fact, the galaxy cluster is so distant that it was only uncovered through the power of gravitational lensing.

Photo of the distant galaxy cluster SPT0615 as imaged by the Hubble Space Telescope.Featured image credit: ESA/Hubble & NASA, I. Karachentsev et al., F. High et al.

As The Inquisitr previously reported, the principle of gravitational lensing is an effect of gravity associated with Albert Einstein’s theory of relativity and states that mass can bend light. This means that massive galaxies can bend the light of more distant, fainter objects located far into the background, boosting their brightness so that it becomes visible. As a result, these objects – known as gravitational lenses – can be used as “cosmic magnifying glasses” to spot distant, faint galaxies lying far behind them and which otherwise would remain unseen.

Discovered some 10 years ago by the South Pole Telescope in Antarctica, the SPT0615 galaxy cluster has slowly been revealing its secrets. One of the precious gems hiding behind this massive structure is a striking galaxy called SPT0615-JD – an object so ancient that it dates back to just 500,000 years after the Big Bang.

Forged in the infant years of the universe, the glimmering galaxy is one of the earliest structures to take shape in the cosmos. Boasting the title of “farthest galaxy ever imaged by means of gravitational lensing,” this embryonic galaxy only weighs around 3 billion solar masses. That’s roughly one-hundredth the mass of the Milky Way galaxy.

In addition, SPT0615-JD is less than 2,500 light-years wide, measuring just half the size of the famous dwarf galaxy known as the Small Magellanic Cloud – one of the tinier satellites of the Milky Way.

A closer look at the ancient galaxy SPT0615-JD, imaged by Hubble in 2018.
A closer look at the ancient galaxy SPT0615-JD, imaged by Hubble in 2018.Featured image credit: NASA , ESA, and B. Salmon (STScI)(CC BY 4.0 )

While our space telescopes have managed to detect a few other primitive galaxies in the past, all dating back to the early days of the universe, those objects were too small and too distant to be seen as more than plain red dots.

“However, in this case, the gravitational field of a massive foreground galaxy cluster, called SPT-CL J0615-5746, not only amplified the light from the background galaxy but also smeared the image of it into an arc (about 2 arcseconds long),” notes the ESA.

As such, astronomers now have the opportunity to study this magnificent object to learn more about the early cosmos. By examining ancient celestial structures such as the SPT0615-JD galaxy, scientists slowly inch their way closer to piecing together a “picture of what the very early universe looked like,” so that they may “uncover more about how it evolved into its current state,” explains NASA.

“Just as ancient paintings can tell us about the period of history in which they were painted, so too can ancient galaxies tell us about the era of the universe in which they existed.”