Galaxies don’t just evolve randomly in space – their cosmic “neighborhood” can literally change the course of their entire lives. And this is the part most people miss: where a galaxy lives might matter just as much as what it’s made of.
A new set of observations from an Australian radio astronomy team shows that a galaxy’s position in the universe plays a major role in how it forms, grows, and eventually ages over time. Using data from the Deep Extragalactic Visible Legacy Survey (DEVILS), researchers have begun to map distant galaxies in far greater detail, giving scientists a clearer view of how environment shapes their life stories.
A new window on distant galaxies
DEVILS is an ambitious survey designed to study galaxies billions of light-years away, capturing how they looked when the universe was much younger. The first data release, along with several recent scientific papers, provides a richer picture of these distant systems, including their shapes, sizes, and how fast they are forming new stars.
By examining large numbers of galaxies across different regions of space, the survey helps astronomers compare “busy” cosmic areas packed with galaxies to quieter, more isolated zones. This makes it possible to see patterns in how surroundings affect galaxy evolution, rather than just looking at single objects in isolation.
Why location shapes a galaxy’s life
Researchers found a clear trend: a galaxy’s environment strongly affects its structure, its physical size, and how quickly it grows over time. In denser regions of space, where many galaxies cluster together, galaxies tend to develop differently than those drifting mostly alone in quieter cosmic suburbs.
To make this intuitive, the team compares galaxies to people living in different communities. Just as someone raised in a fast-paced city can have a different lifestyle and personality than someone from a remote town, galaxies in crowded regions often follow a very different evolutionary path than their isolated counterparts.
The “city vs. countryside” universe
In the universe, regions packed with galaxies act like bustling urban centers, while lonely galaxies resemble homes out in the countryside. Galaxies embedded in these cosmic “city centers” usually grow more slowly and show distinct internal structures compared with galaxies that evolve in relative isolation.
One reason is that crowded environments encourage frequent interactions between galaxies, including close passes, gravitational tug-of-wars, and even mergers. These encounters can disturb their shapes, funnel gas toward or away from star-forming regions, and ultimately reshape how they look and behave.
Competition for raw materials
In dense areas, galaxies do not just coexist; they also compete for limited supplies of gas, which is the essential fuel for forming new stars. When many galaxies draw from the same pool of material, this competition can reduce the amount of cold gas each one has available, slowing down or even shutting off star formation.
Over time, this can cause some galaxies in crowded regions to “age” faster, running out of star-forming fuel earlier and becoming inactive or “dead” systems while others elsewhere in the universe are still actively forming new stars. In contrast, galaxies in more isolated environments often retain their gas for longer, allowing them to keep building new stars and growing over extended periods.
A controversial question for you
Here’s where it gets controversial: if environment is so powerful, does that mean a galaxy’s fate is mostly predetermined by where it’s born, or can internal processes still override its surroundings? Some astronomers argue that internal factors like black holes, stellar winds, and supernova explosions are just as important as environment—maybe even more so in some cases.
What do you think: is a galaxy mainly a product of its cosmic neighborhood, or do you believe its internal physics can rebel against its environment and change its destiny? Share your take—do you agree that “location is destiny” in the universe, or do you see it differently?