Chronological sequence of the close interaction between two spiral galaxies (from top left to bottom right).

Initially, the two galaxies approach each other. After the collision, both become distorted. Tidal tails begin to form and will continue to adorn the remnants of the collision for a long time after the initial impact (as seen in the last three images of the sequence).

– Good evening. What’s your name? My name is NGC 5257.

Usually, for two strangers to start a conversation, someone has to introduce them first. Otherwise, it’s considered completely “improper” for them to talk to each other.

– This is Mr. X.

– This is Ms. Y.

Only then do they start talking. They begin to dance around each other. Now, it’s no longer “improper.”
So, is it considered “proper” for one galaxy to spin around another without speaking? But who made these rules?
Who asked the two galaxies if they wanted to be so close together?
Gravity doesn’t ask anyone.
Do you think Newton was asked whether he wanted the apple to fall on his head? Of course not. The apple simply ripened, and it was time for it to detach from the tree. It detached. Then gravity took over—without asking anyone.
And so, the fallen apple began its journey toward the center of the Earth. Unfortunately, Newton’s head just happened to be in its way.

With humans, it’s different. One asks the other: “Will you marry me?”
If they get married, only then do they begin their wild dance!
Meanwhile, galaxies start their wild dance around each other without many questions, demands, conditions, or dreams for the future. And whatever happens is simply welcomed.
Will new stars form in the compressed interstellar gas of the galaxies? They will be gladly welcomed.
Will black holes form at the centers of the galaxies involved in the cosmic dance? They, too, will be welcomed.
Or maybe neither will happen. That possibility will also be welcomed.
But NGC 5257 and NGC 5258 dance beautifully!
Is this mesmerizing dance also a result of gravity?

At first, one galaxy approaches the other, both filled with an infinite desire for connection and unity. They collide, and a very warm, red region forms between them.
Then, one begins to tear the other apart. Oh, what’s happening here? One raises its arms in despair. The other does the same. Matter flows between them.
A powerful wind carries away material from both galaxies.
In the end, their centers merge into one.
And so, a single remnant is born from the union of two galaxies.

Does NGC 5257 enjoy the dance at all?
What about NGC 5258?

Or am I the only one enjoying watching them spin and devour each other?
Cannibals!
This is called galactic cannibalism—one galaxy consuming the other.
And yet, at the beginning of their dance, they seemed to truly love each other, as if neither wanted to harm the other.
But does the fact that they consumed each other mean they didn’t love one another?
Or… does it mean the exact opposite?

NOTES
An example of interacting galaxies: NGC 5257 and NGC 5258.