Welcome back for part 2 of a very in depth edition of Ask ARSE!

If you missed part 1, never fear. You can find it here.

As a little refresher, here's the question forwarded to us by a friend of the page.

"Hey guys my name is Michael and I love the page. Have you thought about making a YouTube channel? I was watching a YouTube documentary about the size and scale of the universe especially how everything takes millions of years to happen and we are a blink in the eye of time. What I was wondering was what does the future hold for Earth and the universe? When does it all end? It has to end some time right? Thanks, guys and keep spreading ARSE"

So, where were we?

Oh that's right. Earth will most likely be hit by a mega-collossal asteroid in In 100,000,000 years...

Moving on.

In 250,000,000 million years from now, all of the continents left on Earth will converge to create one supercontinent, most likely the below image called Pangea Ultima.

 

 

Pangea Ultima will then split apart about 500,000,000 years later and form entirely new continents unrecognisable to us. 

In 600,000,000 years, our sun will increase in luminosity. This results in higher levels of solar radiation and in turn a decrease in carbon dioxide in the atmosphere. 

Sounds good to our current understanding of the greenhouse gas, right?

But if levels fall too low - and in 600 million years they will - all plant life that survives on photosynthesis ill die. 

Then what happens when all plants die? All animal life dependent on plants die, then all predators that depend on eating herbivores die. So, most of all life.

In about 1,000,000,000,000 (one billion) years, solar luminosity will be just 10% higher than now. Doesn't sound like much?

Well, it's enough to evaporate every ocean on Earth and turn our atmosphere into a 'moist greenhouse'. Another side effect is our tectonic plates will stop moving entirely, and in-turn the entire carbon cycle will end. This is the 'biogeochemical cycle that exchanges carbon with the biosphere, pedosphere, geosphere, hydrosphere, and atmosphere of the Earth'. This means an end to all oxygen. 

In approximately 2,000,000,000,000-3,000,000,000,000 (2-3 billion) years, the planets magnetic dynamo (our planet's magnetic field) will most likely stop. This means low boiling point chemicals in our upper atmosphere will be lost into outer space as our magnetosphere decays. The outer core of the Earth freezes as it loses heat to the void of space while the inner core continues to grow. 

 

 

Another billion years after this (four billion years from now), Earth's increased temperature will cause a runaway greenhouse effect where the surface of Earth is so hot it melts. The average surface temperature is 149°C.

At this point, everything really, really is dead. Even Bacteria is microwaved into extinction. Earth cannot sustain unicellular or non-nuclei containing organisms. Metaphorically, our planet has flatlined and died.

Somewhere around this time, our galaxy has collided with the nearby Andromeda galaxy. This creates the 'Milkomeda' galaxy. Yep, that's the name they came up with. The collision should send hundreds of millions to billions of stars and planets, including our solar system.

In 5,400,000,000,000 (5.4 billion) years, our Sun has depleted its hydrogen supply and begins its evolution into a red giant. Earth and Mars are tidal locked and scorched as the sun expands. 

Earth is now a charred husk. And the most likely course for the next 7,500,000,000,000-7,900,000,000,000 (7.5-7.9 billion) years is space limbo until our Sun enters its red giant phase and expands 256 times its size beyond Earth's orbit. 

 

 

And that's the end of Earth. 

Mercury and Venus are consumed by the Sun and its theorised that Mars will not be habitable, but the Saturnian moon Titan could be.

A million years after this (8 billion years from now), the Sun shrinks back into a white dwarf just over half the size it is now. If the expansion did not engulf Earth, it is a dark and barren world with temperatures many hundreds of degrees below zero. 

Approximately 14,400,000,000,000 (14.4 billion) years from now, the Sun becomes a black dwarf with lower temperatures and almost no luminosity at all. This makes the Sun near invisible to the naked eye, despite being a huge ball of carbon. Some have theorised that pressure would turn the black dwarf into a massive diamond. We can't be sure, because the Universe isn't old enough for a Black Dwarf to exist yet. However...

 

 

The Sun is now effectively dead.

In the 'Big Freeze' hypothesis, the Universe continues to expand and all galaxies beyond the Milkomeda's local group to disappear beyond the observable Universe. Travel, and meeting another alien species is near impossible at this point. The Universe would be so drawn out that any life here would assume that there is nothing beyond their galaxy. They'd probably assume their galaxy is the Universe, because how would they know there's anything beyond it? 

The Big Bang would leave no trace of occurring, which would leave the alien species we mentioned with the assumption the Universe always was and always will be. The local Milkomeda group begins to merge into one. 

In 1 trillion (1,000,000,000,000) years, there are no new stars because no galaxies mean no gas clouds to form them. Stars will reach the end of their lifespan and with no nurseries creating new ones the Universe goes black. Planets exist in the dark. The local Milkomeda group finishes merging and, for all intents and purposes - is the only thing existing within the reality of space as we understand it. Everything is too far away to comprehend.

30 trillion (30,000,000,000,000) years from now some stars will collide and form supernovae, but most will zoom through empty space until they reach the end of their lifespan. 

100 trillion (100,000,000,000,000) years from now there is no free hydrogen in existence and the Universe begins the 'Degenerate Era'. 

One Hundred and Twenty Trillion(120,000,000,000,000) Years from now 99.9% of all stars have burned out, with red dwarfs being the last to go. The only remaining objects are Brown Dwarves, White Dwarves, Neutron Stars and Black Holes which consume their power sources and begin to 'die' in that order.

It's getting difficult to explain the time signatures at this point, but one hundred quintillion (quintillion has 18 0's) years from now 90% of the Brown & White Dwarves, Neutron Stars, and Black Holes are gone or have been swallowed by large Black Holes. The Universe has expanded to the point where no single object will ever see another object ever again. 

Every planet in our solar system is shattered during a collision with the Black Dwarf that was previously our Sun. The remains will most likely be swallowed by the supermassive black hole in the centre of the Milkmeda merged galaxy. 

One nonillion ( 1 with 30 0's after it) years from now, nearly everything has been consumed by gargantuan Black Holes that add mass with every object they devour. As the only objects left are colossal in size, the Black Holes can and will leave the universe - as it has become - mostly void. 

This is the point that the universe is at *drum roll*...

Just half its lifespan.

Now, just 1.342×10^99 (this means there are 99 0's after the 1.342) years, all Black Holes have dissipated into Hawking radiation or formed one singular Black Hole of unfathomable mass. This too will dissipate into radiation and disappear, leaving nothing. 

 

 

Forever...

And ever...

And ever...

Until...

 

 

BANG!

Thanks for reading and sticking with us. This was a fun one that took a lot of time and effort. So if you feel inclined, please share with a friend to spread ARSE!

#Space_Aus