It's clear from the images that the puffy structure, which is located 10,000 light years away, is still growing from our planet's point of view. The team also noticed that the circle's rightmost and lower-right parts grow twice as fast as its left side. They believe that's caused by the differences in the density of the gas enveloping the remnant. The astronomers published a paper detailing their findings, but you can watch and listen to the most important bits in the film below, which also features decades of radio wave observations.