Space

Advanced galaxy far, far away raises questions about cosmic evolution

Advanced galaxy far, far away ...
A reconstruction of the galaxy SPT0418-47, which is the most distant Milky-Way-like galaxy ever seen
A reconstruction of the galaxy SPT0418-47, which is the most distant Milky-Way-like galaxy ever seen
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A reconstruction of the galaxy SPT0418-47, which is the most distant Milky-Way-like galaxy ever seen
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A reconstruction of the galaxy SPT0418-47, which is the most distant Milky-Way-like galaxy ever seen
The galaxy SPT0418-47 originally appeared as a ring of light, caused by the gravitational influence of a closer galaxy
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The galaxy SPT0418-47 originally appeared as a ring of light, caused by the gravitational influence of a closer galaxy

Astronomers have spotted a galaxy with a structure similar to the Milky Way. That’s not particularly surprising in itself – our home galaxy is quite run-of-the-mill – but the weird thing is that this one is 12 billion light-years away, meaning it’s very well developed for its age.

While we don’t fully understand how galaxies form, it’s generally believed that those in the early days of the universe were turbulent and chaotic. It took many billions of years before they settled down into structures like the Milky Way, with a rotating disc, a bulge in the center, and spiral arms on the outskirts.

But the newly discovered galaxy, known as SPT0418-47, bucks this presumed trend, sporting a disc and bulge structure that’s very before its time. The galaxy is located some 12 billion light-years from Earth, which means we’re seeing it as it was 12 billion years ago, due to the incredible distance involved. At that time the universe was only about 1.4 billion years old, which according to current theories means these galaxies should still be chaotic blobs of stars.

“This result represents a breakthrough in the field of galaxy formation, showing that the structures that we observe in nearby spiral galaxies and in our Milky Way were already in place 12 billion years ago,” says Francesca Rizzo, lead researcher on the study.

It may be the most distant Milky-Way-like galaxy ever seen, but the team predicts that SPT0418-47 is destined to evolve into a different beast – namely an elliptical galaxy, which is more like a squashed sphere that isn’t forming new stars very fast.

The galaxy SPT0418-47 originally appeared as a ring of light, caused by the gravitational influence of a closer galaxy
The galaxy SPT0418-47 originally appeared as a ring of light, caused by the gravitational influence of a closer galaxy

Resolving the galaxy’s structure wasn’t easy. At that great distance, galaxies are normally very faint, but this one just so happened to be magnified by the gravity of a much closer galaxy, through a phenomenon known as gravitational lensing. That spread the light from SPT0418-47 out into a ring, and the team had to reconstruct its true shape using computer modeling.

The team says that the surprising discovery of such a well-organized galaxy in the early universe will require a rethink of what we thought we knew about galaxy evolution.

The research was published in the journal Nature.

Source: Max Planck Institute

8 comments
bwana4swahili
Not at all surprising since the universe is probably far older and larger than what we currently see simply due to space expanding at greater than the speed of light...
mediabeing
bwana4swahili Space is not expanding at 'greater than the speed of light'. Change my mind.
Robert Wing
@mediabeing Space doesn't follow the law of physics. https://www.space.com/33306-how-does-the-universe-expand-faster-than-light.html
Stephen Wyman
With each new observation platform we discover that the universe is bigger than we'd imagined... The universe defined by the, "Big Bang," was not the entire universe. Time and space beyond the, "localized event," that was the Big Bang are now being observed.
bwana4swahili
@mediabeing Didn't pay attention to physics in high school?
Si77
The Milky Way takes 200 million years to rotate. If this distance galaxy rotates at a similar speed, then the maximum rotations is 7. It would seem highly improbable, if not impossible, to form this complexity in 7 years. Therefore the universe must be much older, and the big bang theory is wrong. Yet astronomers hang to it like the church against Galileo.
Robert Fink
Hmm. Maybe the galaxy didn't follow cosmic evolutionary development, maybe it was created by the Creator, and then he stretched out the heavens at a speed faster than the speed of light.
Shafia Stevens
With the huge disclosure projects by governments happening at this time, the reality of space travellers is getting ever closer. I hope I live long enough to witness it and hear from people who know about the mysteries of our solar system and the universe beyond. Thanks for sharing your fascination :)