Astronomers have used the Hubble Space Telescope to observe a David and Goliath-type battle between a massive galaxy and a much smaller one, 220 million light-years from Earth.
One of the outcomes of this gravitational struggle could see NGC 7752 ripped apart and its stars dispersed into the larger spiral galaxy, a form of cosmic cannibalization that links these galaxies to our own.
The larger spiral galaxy is NGC 7753, and its smaller galactic companion, known as NGC 7752, both lie in the constellation of Pegasus.
Alien galaxies
The fact that the smaller galaxy appears to be attached to the larger galaxy led to the two being added to the Atlas of Peculiar Galaxies compiled by the astronomer Halton Arp in 1966, with the designation Arp 86.
NASA predicts that the gravitational battle between the two galaxies will eventually result in NGC 7752 either being flung into interstellar space, or the encounter will lead to the destruction of the smaller galaxy, with its stars, gas, and dust spread throughout the larger galaxy.
This consumption of a smaller galaxy by a larger one could be similar to an event that astrophysicists suspect happened in the history of our galaxy, which has a similar spiral shape to NGC 7753, when it was less than 5 billion years old.
The form that the Milky Way takes today could have been influenced by an encounter with a smaller galaxy, Gaia-Enceladus, and ours, in which the more diminutive galaxy was shredded and consumed.
Violent confrontation
Research published in the journal Nature Astronomy indicates that this violent confrontation occurred about 10 billion years ago, and led to the explosion of stars about 4 billion years later and the emergence of the Milky Way in its current form.
This may not be the last collision in the history of the Milky Way, as it is currently on a collision course with the Andromeda galaxy.
When this collision occurs, NASA says it will reshape the Milky Way, and that the part that contains the Sun and Earth could become a completely different place from what we know today.
But according to scientists, this collision will not occur until after 4 billion years, because the distance between the two galaxies is currently 25 million light years.
According to the author, this type of galactic collision is not a common occurrence in the universe, and researchers believe that it plays an important role in cosmic evolution, as the collision between galaxies leads to the redistribution of gas and dust, which often results in the formation of huge clouds of gas and the formation of stars.
Sources:
https://www.nasa.gov/image-feature/goddard/2021/hubble-watches-an-intergalactic-dance