This stretching out of older light into infrared waves is called “redshift”.
When they set out, space wasn’t just older, it was much, much smaller and condensed, explains ANU astronomer Dr Brad Tucker, who will be using Webb to hunt for supernovas (dying stars). Light waves from the oldest stars, meanwhile, have also been warped by the expanding universe around them. The sun’s light, for example, takes roughly eight minutes to reach us on Earth, so when we look up at the sky we’re seeing our star on a time delay. But in a universe this vast, even light speed takes time. Light travels faster than anything in the universe (299,792 kilometres per second) since photons have no mass to slow them down. Light particles (known as photons) travel in waves, their length determining which colour we see. So, how did we pull off what has been called “the most expensive astronomical gamble in history”? And what might Webb tell us about the universe – and ourselves? Yet within it, Webb has caught the twinkle of primordial galaxies and scientists say the expanded view could help solve all kinds of enduring questions – from whether we’re alone in the cosmos to how it all began. The first image – the deepest glimpse of the universe ever recorded – represented just a sliver of the night sky, smaller than a grain of sand held at arm’s length. (“And it’s going to remind the world that America can do big things,” he said.) Webb’s first images have been beamed back to Earth, released by NASA in what US President Joe Biden called a historic moment not just for science but for all of humanity.
This landscape of “mountains” and “valleys” speckled with glittering stars is actually the edge of a nearby, young, star-forming region in the Carina Nebula, as captured by the James Webb telescope. “But everything’s running even better than expected. “There were hundreds of failure points” where a tiny malfunction could have turned the whole mission to space junk. “It could have just blown up on the launch pad,” says University of Queensland’s Dr Benjamin Pope, one of the Australian astronomers who will be using Webb. Late in 2021, after more than four decades of work (and delays), and billions of dollars, NASA shot it into space. This is the James Webb Space Telescope, one of the most complex machines ever built. To see it, we need a time machine of sorts – a giant telescope powerful enough to catch the heat of infrared light in the cold darkness of space, but light enough to be carried by a rocket more than a million kilometres away from Earth a machine that can unfurl and assemble itself to precision measurements smaller than the width of a virus, with a sun shield as big as a tennis court on its back. Their light has taken more than 13 billion years to reach us, stretched beyond the visible spectrum into infrared as the universe has expanded. Not just deep in space, but deep in time, when the first stars were burning through the fog that forged the universe. Here on our little blue rock in the outer suburbs of the Milky Way galaxy, we can now stare into the deepest heart of the cosmos. Normal text size Larger text size Very large text size
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