watershed-moment-for-cosmology-fundamentals-need-revisiting

For millennia, the star-lit sky has fascinated humans and triggered profound questions about the cosmos, the mysteries of its origin and our place in it. This pursuit may have reached its watershed moment now, thanks to the stunning images being beamed by the James Webb Space Telescope (JWST), the most sophisticated ‘window to the universe’ ever built by mankind.

 

The latest views delivered by the $ 10 billion infrared telescope have left the researchers awe-struck and yearning for more.

 

Challenging the standard model

 

The JWST is equipped with infrared-sensing instruments capable of detecting light that was emitted by the most ancient stars and galaxies. Essentially, the telescope allows scientists to see back in time roughly 13.5 billion years, providing a better understanding of how galaxies are born and how they evolve over billions of years.

 

In just its first year of scientific operations, the $10-billion infrared telescope has delivered stunning views of the nascent universe, finding large numbers of surprisingly bright galaxies that existed at a time when the cosmos was in its infancy.

 

With its 6.5-meter mirror, JWST was designed to investigate this early era, which was mostly out of reach for its predecessor, the 2.4-meter Hubble Space Telescope (HST). Observations thus far have astonished researchers and left them trying to digest exactly what they’re seeing.

 

According to the standard model of cosmology, after the fiery Big Bang 13.8 billion years ago, the universe cooled, and energy turned into matter that eventually coalesced during the first few hundred million years, forming the first generation of infant stars and galaxies.

 

Astronomers thought they had a decent understanding of this process. Most models estimate that a galaxy the size of our Milky Way would not form until roughly 1 billion to 2 billion years after the Big Bang.

 

But, surprisingly, what they found in the images of the early universe were full-fledged stars and galaxies.

 

The JWST’s results suggest that stars and galaxies were forming far faster than anyone expected. The observations showed staggering numbers of galaxies potentially existing as early as 180 million years after the Big Bang. These galaxies are also potentially more massive than cosmologists expected.

 

Adults playing in a kindergarten!  

 

For the longest time, astrophysicists and cosmologists assumed that new-born galaxies would look like the orbs and spidery discs.

 

But, in an analysis of the new images from James Webb, baby galaxies were neither eggs nor discs. They were full-fledged, well-formed galaxies. It was like watching adults play in a kindergarten!

 

That is the tentative conclusion of a team of astronomers who re-examined images of some 4,000 new-born galaxies observed by Webb at the dawn of time.

 

This is a challenge to the standard model and could force the scientists to revisit the long-held assumptions. Besides profoundly altering the present understanding of how galaxies emerge and grow, the latest findings could also offer insight into the mysterious nature of dark matter, an invisible form of matter that astronomers say makes up a major part of the universe. Dark matter engulfs galaxies and provides the gravitational nurseries in which new galaxies arise.

 

Astronomers using the JWST have discovered a massive galaxy that is so old that its existence should be impossible, challenging current models on how these structures form. It is found to contain more stars than the Milky Way — despite forming just 800 million years after the Big Bang.

 

This pushes the boundaries of our current understanding of how galaxies form and evolve. Having these extremely massive galaxies so early in the universe is posing significant challenges to our standard model of cosmology. That could mean bringing new ideas to the forefront—while leaving others in the cosmic dustbin.

 

It is possible that the primordial universe was much denser and more compact than researchers think, perhaps allowing gas and dust to collapse especially quickly into stars.

 

As per the current understanding, the observable universe is estimated to have two trillion galaxies, each containing as many as a trillion stars. But the visible universe is only a fraction of what is out there. Most of the matter in the cosmos could exist in the form of dark matter.

 

Penetrating gaze

 

Designed to capture ancient light emitted more than 13 billion years ago as the embryonic universe was still learning how to create stars and galaxies, the James Webb telescope—30 years in the making—is providing a stunning new view of the cosmic firmament.

 

With its penetrating infrared gaze, the most sophisticated space lab ever built is now revealing planets, stars, and more in a whole new way. The breath-taking images being beamed back by the telescope reveal giant celestial landscapes of dust and gas, the deepest reaches of the Universe and huge, interacting galaxies, and dying stars in their final throes of life.

 

From the deepest realms of the cosmos all the way home to the celestial backyard of our Solar System, there is not a single domain of the Universe that the JWST cannot make a meaningful investigation.

 

Launched in 2021, the primary mission of the telescope is to reveal the "let there be light," moment when the stars and galaxies first ignited after the Big Bang.

 

The unique design and the sophistication of NASA's telescope make it ideal to search for signs of potentially life-supporting atmospheres around scores of newly documented exoplanets—celestial bodies orbiting distant stars.

 

Fasten your seatbelts for many more exciting discoveries ahead!