Discovery Of Ancient, Dead Galaxy Challenges NASA’s Perception Of Galactic Evolution, Here Is Why
NASA has discovered an old and dead galaxy that has changed the perception of researchers about evolution in space. This is the first time that scientists from the American space agency have spotted a dead galaxy that has a spiral shape, with the help of the Hubble Space Telescope.
According to NASA, detecting such a galaxy from the universe’s early history challenges what astronomers know about the evolution and formation of galaxies. In general, scientists believed that all the primeval galaxies were elliptical. However, the newly discovered ancient dead galaxy is spiral shaped and does not have the usual blue hue.
Incidentally, spiral-shaped galaxies are usually blue due to the presence of younger blue stars. It is also one of the factors that contributed to experts thinking that spiral galaxies are younger and the earliest dead galaxies were elliptical.
The new discovery, however, challenges this view. This is the first time that a dead galaxy with a spiral shape has been spotted. The finding has led experts to believe that other dead galaxies could have also originated as spirals that later became massive ellipses during the course of evolution.
"This new insight may force us to rethink the whole cosmological context of how galaxies burn out early on and evolve into local elliptical-shaped galaxies," study leader Sune Toft said. "Perhaps we have been blind to the fact that early "dead" galaxies could, in fact, be disks, simply because we have not been able to resolve them."
So how could the evolution from spiral to elliptical galaxy happen? According to a 23 ABC News report, when galaxies merge, there is a probability that they come together at different angles. This impacts the paths that stars follow and thereby creates the random orbits, which is one of the key features of elliptical galaxies.