Hubble's famous space telescope captured two passing galaxies, making contact for the first time. Known as UGC 2369, the presented duo is one day fused to merge into a single galaxy. But for now, the two galaxies are just getting to know each other.
In the image below, the couple can be seen swirling around each other as their mutual attraction (read: gravity) draws them closer together. According to the European Space Agency (ESA), all that currently connects the two galaxies is a "thick bridge of gas, dust and stars", almost holding hands.
This is UGC 2369, seen by NASA / ESA @HUBBLE_space . These are actually two galaxies interacting, drawn closer to one of their gravitational pulls, in a similar process that our galaxy, the Milky Way, will see collide with the Andromeda Galaxy. See https://t.co/ZzsB04tVNr pic.twitter.com/bDAtydgWSl
̵1; ESA (@esa) August 5, 2019
Galaxies are extroverts by heart – most belong to the galactic groups or clusters. In such close quarters, interaction between two or more members is not uncommon. Even when the collision is somehow avoided, intense gravitational pull can still twist the galaxy out of shape.
In many ways, this makes galactic interactions so stunning to watch. For example, galaxy flyovers – where no contact is made – can create permanent bases, rods and tidal tails that extend from the center of the galaxy, turning it into unusual shapes and causing new outbreaks of star formation.
Mergers, on the other hand, are much more destructive, and this is especially true when galaxies are about the same size. These larger events are less common than minor mergers, but our own galaxy was thought to have one coming into its future.
Currently, the Milky Way we live in is occupied with the fragmentation and ingestion of two nearby dwarf galaxies known as Sagittarius and Canis Major. One day, however, our galaxy can turn into eating.
Astronomers are quite sure that the Milky Way and Andromeda galaxies will collide billions of years in the future – turning into Milcomeda, if you will, just when it can be and how it will play is still for debate.
Although the merger of UGC 2369 looks fresh, this galactic duo is actually considered to be a relatively advanced stage. Hubble's training in interactions like this can give us an idea of the fate of our own galaxy.