Researchers have answered a decades-old question about the evolution of the galaxies by leveraging the power of artificial intelligence (AI).

By the 1970s, researchers had confirmed that lone galaxies tend to be spiral-shaped.

And the galaxies found in clusters were smooth and featureless. Which are called elliptical and lenticular (lens-shaped).

Astronomers from the International Center for Radio Astronomy Research (ICRAR) have uncovered the reason for these differences in the sizes of galaxies.

Lead author Dr. Joel Pfeffer said the research explains the 'morphology-density relation' where clustered galaxies appear smoother and more featureless than their solo counterparts.

The study utilized the powerful EAGLE simulations to analyze a group of galaxies in detail, using an AI algorithm to classify galaxies by their shape.

The researcher found that the spiral arms on galaxies are so fragile, and as galaxies move into higher densities in clusters, spiral galaxies begin to lose their gas.

This loss of gas causes galaxies to 'drop' their spiral arms, which transform into a lenticular shape.

Galaxy mergers are another reason why galaxies change shape. Which becomes a large elliptical galaxy after two or more spiral galaxies crash together.

The study also identified several lenticular galaxies outside the high-density regions, which are thought to have formed from the merger of two galaxies.