Arp 122, a peculiar celestial formation situated approximately 540 million light-years from Earth, is not a solitary spiral galaxy as it may appear. It is, in fact, a duo of galaxies—NGC 6040, a distorted spiral galaxy viewed edge-on, and LEDA 59642, a spherically-shaped spiral galaxy. These two cosmic entities are currently in the throes of a cataclysmic collision, a preview of what’s expected for our own Milky Way when it eventually collides with the Andromeda Galaxy.
The Hubble Space Telescope Captures Galactic Merger
This grand galactic interaction has been captured by the Hubble Space Telescope, offering a glimpse into the slow, yet dramatic, processes that characterize cosmic collisions. As the galaxies continue their inexorable fusion, the event may unfold over hundreds of millions of years, demanding patience from those observing from afar.
Understanding the Aftermath of a Galactic Collision
Galactic collisions, while occurring over vast time scales due to the immense distances involved, can lead to periods of intensified star formation and significant structural changes. As gas clouds collide and gravitational forces act, the galaxies can emit brightness up to ten times greater than when they were separate. Eventually, the merging of the galaxies typically results in the formation of a single, unified galaxy.
These collisions can also give rise to stellar formations known as tidal tails, exemplified by Arp 122 and other interacting galaxies like the Mice Galaxies. These stellar streams trail behind the colliding bodies, while ripples and other structures can emerge, akin to the patterns seen in a disturbed pond. Astronomers study these features to glean insights into the nature and history of galaxies and their interactions.
Despite the dramatic appearance of such cosmic mergers, there is no immediate cause for concern regarding the eventual meeting of the Milky Way and Andromeda galaxies. That particular galactic event remains a distant future occurrence, estimated to happen in about four billion years.
