NASA has released a new video showing how the supernova Cassiopeia A has changed over a decade. According to the agency, the video provides a rare opportunity to watch a cosmic object evolve within a period that humans can relate to.

According to NASA, Cassiopeia A, also known as Cas A, is located about 11,000 light-years from Earth. It is the glowing remnant of a massive star that exploded and died after running out of fuel and collapsing under the weight of its own gravity.

For the short video, NASA used the images taken by its Chandra X-Ray Observatory from 2000 to 2013. The agency also used a few images taken by its other observatory, the Hubble Space Telescope. The clip was shared through NASA’s website for Chandra.

As noted by NASA, being able to see how a cosmic object evolves within a span of 13 years is a rare opportunity since these kinds of events usually take hundreds to thousands of years to happen.

“The video shows Chandra observations of Cas A from 2000 to 2013. In that time, a child could enter kindergarten and graduate from high school,” NASA stated. “While the transformation might not be as apparent as that of a student over the same period, it is remarkable to watch a cosmic object change on human time scales.”

In the video, the evolution of Cas A is characterized by its expanding blue outer region, which is actually the shock wave from the star’s initial explosion. As the shock wave rapidly moves across space, it interacts with other cosmic materials.

The interaction creates a second shock wave that travels in the opposite direction of the first one. The second shock wave, which has the same color as the first one, moves away from the outer region and into the center of the supernova.

“As the blast wave travels outwards at speeds of about 11 million miles per hour, it encounters surrounding material and slows down, generating a second shock wave - called a "reverse shock" - that travels backward, similar to how a traffic jam travels backwards from the scene of an accident on a highway,” NASA explained.

Supernova remnant
Supernova remnants are the debris from exploded stars. G292.0+1.8 is a rare type of supernova remnant observed to contain large amounts of oxygen. Because they are one of the primary sources of the heavy elements (that is, everything other than hydrogen and helium) necessary to form planets and people, these oxygen-rich supernova remnants are important to study. The X-ray image of G292+1.8 from Chandra shows a rapidly expanding, intricately structured field left behind by the shattered star. The image is colored red, green, teal and purple in X-rays ranging from the lowest to highest energy levels.Recently the first detection was made of iron debris from the exploded star. Authors constructed a map of this debris, along with that of silicon and sulphur, to understand more about the explosion. They found that these three elements are mainly located in the upper right of the remnant. This is in the opposite direction from the neutron star that was formed in the explosion, and was then kicked towards the lower left of the remnant. This suggests that the origin of this kick is gravitational and fluid forces from an asymmetric explosion. If more than half of the star’s debris is ejected in one direction, then the neutron star is kicked in the other direction so that momentum is conserved. This finding argues against the idea that the copious amounts of neutrinos formed in the supernova explosion were emitted in a lop-sided direction, imparting a kick to the neutron star. NASA/CXC/SAO