Imagine trying to photograph a mosquito at the far end of a football field. In a normal photo you wouldn't see it. You could use a telephoto lens, and it would still just about be visible.
Now imagine someone left a football-sized ball of glass on the ground. It can produce a magnified but distorted view of the mosquito. You could take a photo of the glass ball through the telephoto lens. And if the mosquito just happened to move so it was in the right place, what you'd get is a magnified, distorted view of the mosquito.
That is the trick the James Webb Telescope is trying to pull. Sure, it's a powerful telescope, with unbelievable imaging power and detail. But that's just the start.
Any massive object, like a cluster of galaxies, will affect the light travelling near it. Its gravity is so strong it will bend the light, in a similar way to a glass ball. Small, dim objects just behind the galaxy cluster will be magnified and distorted, just like the glass ball does to that mosquito. This is called 'gravitational lensing'.
Now look at that first picture from the James Webb Telescope, of a galaxy cluster called 'SMACS 0723'. It's a brilliant image, with a cluster of galaxies in the centre. But the exciting bit is the smudged distorted red arcs. They are the image of dim distant stars and galaxies, previously beyond the power of any telescope. They are magnified by the 'gravitational lensing' of the galaxy cluster in the centre.
This picture, the first from the JWT, demonstrates its capability. Since the scientists can work out the exact way the distortion happens, they can use image processing software to reverse the distortion and produce a less distorted image. But that's a project for the future. They now have incredible images to start work on. The game has changed...
Now imagine someone left a football-sized ball of glass on the ground. It can produce a magnified but distorted view of the mosquito. You could take a photo of the glass ball through the telephoto lens. And if the mosquito just happened to move so it was in the right place, what you'd get is a magnified, distorted view of the mosquito.
That is the trick the James Webb Telescope is trying to pull. Sure, it's a powerful telescope, with unbelievable imaging power and detail. But that's just the start.
Any massive object, like a cluster of galaxies, will affect the light travelling near it. Its gravity is so strong it will bend the light, in a similar way to a glass ball. Small, dim objects just behind the galaxy cluster will be magnified and distorted, just like the glass ball does to that mosquito. This is called 'gravitational lensing'.
Now look at that first picture from the James Webb Telescope, of a galaxy cluster called 'SMACS 0723'. It's a brilliant image, with a cluster of galaxies in the centre. But the exciting bit is the smudged distorted red arcs. They are the image of dim distant stars and galaxies, previously beyond the power of any telescope. They are magnified by the 'gravitational lensing' of the galaxy cluster in the centre.
This picture, the first from the JWT, demonstrates its capability. Since the scientists can work out the exact way the distortion happens, they can use image processing software to reverse the distortion and produce a less distorted image. But that's a project for the future. They now have incredible images to start work on. The game has changed...
