A new image from the James Webb Space Telescope shows distant galaxies that look stretched, bent, and even repeated. The golden galaxies in the picture belong to a cluster called MACS J0454.1-0300. Its light has traveled for so long that the image shows the cluster at a time when the universe was roughly 8 billion years old. The strange shapes are caused by gravitational lensing. The huge mass of the cluster bends and magnifies light from objects far behind it.
This effect lets astronomers observe galaxies that would normally be too far away to see. In the lensed areas, they found a group of galaxies from 2 billion years after the Big Bang. The group appears to be merging, which has set off a burst of star formation. Another galaxy dates from only 800 million years after the Big Bang. Some bright clumps appear magnified more than 300 times. Compared with a Hubble image from 2014, Webb's picture reveals hundreds of galaxies that were missing, because Webb is more sensitive to red light.