The most powerful telescope mankind has sent into orbit is opening up our understanding of how life began

Since its launch two years ago, the James Webb Space Telescope has been sending back stunning images that are transforming our understanding of the cosmos

This month marks two years since the most powerful telescope ever built sent its first pictures back to earth.

From its lofty vantage point, beyond the moon in orbit around the sun, the James Webb Space Telescope was tuned to observe the first stars and galaxies being born soon after the dawn of time - about 200 million years after the Big Bang.

For the first time we were able to witness the first stars blinking into life out of the primordial gloom.

But what we saw was even more mind-blowing.

Cosmologists expected to see a lot of new, weak stars starting to form the first galaxies.

Instead, says US astrophysicist Rachel Somerville, it "found a lot of very luminous galaxies at very early times pumping out huge amounts of ultraviolet light.

"The theories that had been published before Webb launched did not predict that large a number of such bright galaxies.

"So that caused a big fuss."

It wasn't just big bright objects causing a big fuss at the beginning of the time.

"We started to find evidence for supermassive black holes that were also much larger, much more massive, and at much earlier times than theory had predicted.

"Maybe those two things go together."

Supermassive black holes, ancient stars that have collapsed in on themselves, are relatively commonplace these days, lurking in the centres of most galaxies.

Richard Easther, Head of the Department of Physics at the University of Auckland, tells The Detail it's an open question as to where those black holes come from.

"Whether the black holes form and then galaxies form around them, or whether the galaxies form and then the black holes form afterwards.

"There's a complex web of interactions that happen in the early universe between particle physics that we don't understand, between black holes that we don't fully understand, between the messy physics that leads to star formation.

"All those things somehow come together to produce what we see, and it's a huge challenge to get all of that right, all of that detail."

Easther says while the JWST results were certainly a surprise, he's not expecting any major rewrites to the cosmological timeline.

"We know for lots of reasons that the universe after the big bang was very smooth, composed primarily of hydrogen and helium, and it would take a significant amount of time before you can form stars…

Go to this episode on rnz.co.nz for more details