Plot Twist: An Entire Galaxy is Passing Through The Milky Way

The Milky Way galaxy will collide with the neighboring Andromeda galaxy in the next 4 to 5 billion years, completely merging with it in the next 6 billion years. But that won't be the first collision of our galaxy with another. The Milky Way is the second-largest member of the Local Group comprising at least 80 known galaxies. Satellite galaxies orbiting the giant ones end up being torn apart and ultimately merging with the massive galaxies.

The Milky Way is already merging with several satellite galaxies, but one of the most prominent mergers is with the Sagittarius dwarf galaxy. Astronomers have found evidence that Sagittarius has already passed through the Milky Way thrice in the past six billion years, which might be the reason behind our existence. But how did scientists make this intriguing discovery? How do they know the number of times the Sagittarius dwarf galaxy passed through the Milky Way? Finally, and most importantly, why is Sagittarius considered the reason behind the existence of life on Earth?

The 15th episode of the Sunday Discovery Series answers all these questions.

REFERENCES:

Created By: Rishabh Nakra
Narrated By: Jeffrey Smith

The Secrets of the Universe on the internet:

[michaelccopelandsr]

Time is fascinating. I worked the subway stations for nearly 10 years. From one end of the city to the other. Every so often I would notice the city would be saying that, "Today just flew by" or "The day was just dragging along."  How can an entire city, with no interaction with each other until they used the subway, complain about the same time paradox unless it was effected by it? MAYBE a time distorted bubble the earth passes through in its revolution around the sun. MAYBE they're the effects of gravitational waves. Either side of the wave effecting time just enough for we humans to notice. Making time seem to drag on the upside and fly by on the downslope. MAYBE they're given off by the sun. MAYBE they're from outside our Solar system and reach us in intervals. ???? 🎶Ti-i-i-ime, is on my side. Yes, it is!🎶
If you can think of a better way to do a blind survey of an entire city, in the small window of opportunity, I'm all in.  Until then, I invite you to spend a couple years in the subways during rush hour and you'll see for yourself.  Just listen as an entire city gets off of work and gets out of school.  You'll see it's more than a, "coincidence of circumstances."  ;-P

[vilchico]

How lucky for people to see the collision in a few billion years, I hope humanity makes it.

[alexbenavidez]

So glad you actually explained this the way you do, because as much as I love astronomy and learning new things about our galaxy and the universe, I never actually know how we know these things about time and space, and a lot of the maths, particularly with quantum physics is utterly above me

But I do want to know what tools and equations it is we use to learn all these things, and I want to track just how that understanding and scientific method itself evolved and grew

How we went from assessing the redshift of stars to determine their distance from us and their age in the universe, and then the life cycles of stars by observing their nature and composition as the further the distance from us, the older things are to literally look back in time at the oldest stars and see what they look when first formed up to their later stages in life, then now that we know how stars are bom, and how they burn through their main sequence and die, we can learn their role in creating planets and solar systems and that all our elements in the periodic table are seeded into the universe from the cores of dying stars going supernova

It's just as fascinating how the continuous understanding of astronomy evolves as theories and predictions are each shown to be true, allowing us to infer conclusions you would never discover by simply just looking at the sky

I think one of the biggest obstacles when it comes to explaining science like astronomy and astrophysics is that paradigm shift and the fact we often have to just trust that what scientists are telling us is true and accurate, because we ourselves often have no way to verify the validity of the research that brought them to this conclusion

Of course this is true for all sciences, and is the reason peer-reviewing and the scientific consensus is a thing, but I think it is especially so when it comes to space as a lot of the physics involved has already proved itself, and new discoveries and theories are always presented on the inference that many, many other theories have proven themselves to be true

This is things like how we know the chemical composition of other stars and planets which I used to take for granted as just a fact we know, but now I'm so curious as to how we worked that out

How do we know that Jupiter is a gas giant? Or that other planets even have a terrestrial surface?

I think there'd be far fewer flatearthers and science illiteracy in general if more of the layman explanations of astronomy included how and why we know this information to be true, instead of relying on such research to be verifiable by others

The idea that there is a global conspiracy to hide the true nature of the earth and space in general is ridiculous, but science that relies heavily on trusting the consensus and only being falsifiable to experts will have those detractors who aren't satisfied with simply believing some kind of authority on the subject

[alexshepherd]

Imagine an intelligent form of life on those streams of stars above the milky way, that forms what's left of the collision, being able to see and comprehend that they're part of a merge with such a large and beautiful galaxy, they would literally see the whole galaxy from their perspective, am I right?

[williegillie]

Funny thing, I always thought Sagittarius A+ was at the center of our galaxy. They must be referring to another Sagittarius

[beetlebob]

I came up with this for a sci-fi novel, not knowing it was a thing. Feels like I'm on the right path. Self-doubt is annoying. This helped me a lot. ❤❤❤❤❤

[michaelccopelandsr]

Ok, how about this way then? Black hole's effect space, matter, and TIME! It's not JUST the intense gravitational pull. It's also the abundance/absence of TIME!* People keep dismissing the TIME. (*When it takes 500k of our years for 1 millionth of a second to pass, it's safe to say there's a relative absence/abundance of TIME.) It's the ebb and flow of TIME that proves it. The "starved" of TIME white hole's ENTIRE existence flashes by in an instant. A black hole is "stuffed" with TIME. That's why things age slower. The black hole's TIME gets so stuffed that particles are, for lack of a better word, "squeezed" into TIME with so much force that they exist in the past, present and future, at the same TIME, in TIME. (QUANTUM PARTICLES, DUH!)  I mean if it walks like a duck, and quacks like a force, it might not be just a causality. There's more to TIME than we think.  Remember, crazy is a compliment.  As it should be

[JupiterEclipse]

I’ve already watched all the episodes of the Sunday Discovery Series.

[michaelccopelandsr]

My idea so I get to name it! Voyager 1 is now in interstellar time or "Mikey's Time." Think of it like Alvin and the chipmunks. "Vyger's" message is sped up now that it's outside our suns time bubble or "Terran Time."  It would be faster still if "Vyger" sent a message from beyond the Milky Way's time bubble. (That name is still up for grabs.) Then there's Outside the Local Group time bubble, so on and so on until we get to the, "True Interstellar Time Standard."  Now that "Vyger" is in interstellar space, it's also in the Milky Way's STANDARD, faster moving, interstellar time or "Mikey's Time."
•Our sun's time bubble: "Terran Time" we know and have measured.
•Milky Way's time bubble or "Mikey's Time." The rate/flow of TIME outside any influence but within the Milky Way: We just got there and are still figuring. Wild guess I'd say time will increase in speed, now and until Vyger is outside the Ort cloud .007-.07% faster, maybe. Just for reference.
•Local Group's time bubble or the rate/flow of time outside of any influence but within the Local Group: Name still open and unknown. Wild guess .08% to a couple seconds faster, maybe. Used just for reference.
•Outside any influence in the, "True Interstellar Time Standard, " or...;-P Name NOT up for grabs BUT just begging to be measured. The rate/flow of time is fastest here so, surfing time here is choice. Though it's best to have your motor boat. ;-P
A minute is a minute in all. It's the rate/flow I'm talking about.
The Milky Way's Interstellar Time Standard will be known as, "Mikey's Time."
Pass it on, please and thank you.

[richardmercer]

Thrice in six billion years? Strange that I didn't notice....

[sonarbangla]

Sagittarius dwarf galaxy entering the Milky Way three times, might have been enough for the fine tuning required for life and consciousness to evolve, but that implies the adjustment of the values of the Milky Way in general.

[Novak]

The miracle thing about the universe is that we can understand it. The universe is not in obligation to make sense to us or to follow laws of physics described by mathematics.

[apollobukowski]

So galaxy A fertilizes galaxy B. 3 times ought to do it.

[simnatercroc]

Am I the only one who saw this thumbnail 5:02 in real life because honestly I saw that ring last year in 2021 looking outside at night with only my eyes and I only saw it once it was beautiful 🤩

[dariornr]

Interstellar distances are so huge it's unlikely for two stars to crash into each other.

[AUcm-]

I'm just finding out about this now, I don't have enough time to do what I wanted to do before the merge occurs. 4 billion years from now, wish me luck everybody.

[JMigUK]

Some of the comments are so unfunny that it makes you wonder how those people made it to the keyboard.

[BigYehudah]

I am utterly blown away by the vastness and beauty of the universe. I have been binge watching secrets of the universe and astrum. Thank you for this content. The heavens declare the glory of God.

[cuzzo]

First connection: 3 billion years ago
Second collision: 1.9 billion years ago.
Third collision: 1 billion years ago seems time getting smaller but I believe in actually 800 million years is when the 4th connection is gonna hit my theory anyways

[lynnadams]

Love learning more from videos like these!!!