Episode 14. The Whirlpool Galaxy, Messier 51, is 31 million light years from earth, which is equivalent to saying you are looking at what the Whirlpool Galaxy "looked like" 31 million years ago.  As you can see the Whirlpool Galaxy (M51) which includes 100 billion stars is gravitationally interacting with a neighboring yellow galaxy NGC 5195 whose outcome will almost certainly be the galaxies merging and forming a single galaxy.   M51 is a very active galaxy with the dust lanes between the spiral arms displaying blue (oxygen) and red (Hydrogen) rich areas, which are birthplaces for new stars.  

The Whirlpool Galaxy was discovered by Charles Messier in 1773.  Of course, back then, with the optics they had, these galaxies appeared as faint fuzzies (clouds) and all astronomers of the day thought they were Nebulas in our own Milky Way galaxy.  The existence of galaxies, other than our own, was not postulated and accepted until the 20th century. Billions of galaxies with 100s of Billions of stars each is now the accepted norm.  The face-on view of the galaxy and closeness to Earth (as far as galaxies go) provides us with one of the most beautiful galaxies in the night sky.

I encourage you to also look at IC4263 at the top of the image in full resolution, which is a Barred Spiral Galaxy 131 million light years from earth.  Barred meaning "central bar-shaped structure composed of stars". 

I captured this astronomical data using wide band (visible light) Lum, Red, Green, and Blue over 3 nights, 6/16/2023, 6/17/2023 and 6/18/2023 from Grandview Campground in the Inyo National Forest which is a stunning Bortle 1 night sky.  This primitive campground is very close to the Bristlecone Forest which has the oldest living trees (Bristlecone Pines) in the world, exceeding 4,000 years old.  With no moon and a Bortle 1 sky, the signal to noise ratio (SNR) is exceptional, which means you can get better data with less exposures and exposure time.  In this example,  I captured the Whirlpool Galaxy  in only 3 nights with the contrast of the image being as good or better than 5 or 6 night captures in a Bortle 2 or 3 night sky.  
Filters, number of exposures, exposure time, total time.
Chroma Lum 50 mm: 15×600″(2h 30′)
Chroma Red 50 mm: 19×600″(3h 10′)
Chroma Green 50 mm: 18×600″(3h 0′)
Chroma Blue 50 mm: 18×600″(3h 0′)
Total Imaging Time = 11h 40min

Click on the image, Top right click on full resolution to see it in more detail.

Episode 14 follow up:
You are looking at an Elliptical or Irregular galaxy (NGC 5195) merging with a normal Spiral Galaxy (Whirlpool).  We are looking 31 million years into the past, so at this moment (whatever that means) they are probably closer to merging.  Interestingly most cosmologists believe that there are no "collisions" when galaxies merge.  Even in galaxies there is so much empty space, relative to matter (stars), that even when these galaxies collide/merge the stars do not actually hit each other.  100 billion stars in the Whirlpool galaxy spread over 65,000 light years in diameter is actually very sparse.  They just do this gravitational dance, sucking matter from the weaker gravitational galaxy to the stronger gravitational galaxy and reshape themselves.  Whether the black holes in the center of the galaxies will merge, it is hard to say.  It all depends on how large their event horizons are (the point of no return).  The Black hole in the center of our Galaxy Sgr A* is 14 million miles in diameter.  In the scale of a galaxy, that is tiny.  If that is a representative size, when galaxies merge the chances of the two Black Holes getting within 14 million miles of each other, so they enter each other's event horizon seems like very slim odds.
In our own neighborhood, the Andromeda Galaxy is a monster galaxy with Trillions of stars.  It's gotten so big because it has devoured galaxies throughout its billions of years of existence and still retains its spiral shape.  In fact, it is on its way to devour our galaxy, the Milky Way Galaxy.  Eventually Billions of years from now, the Andromeda Galaxy will consume the Milky Way and Triangulum Galaxies with most likely no star collisions.