What would happen if our sun suddenly went out?

For an hour

or for a month

or let's say even for a whole year?

What would happen to mankind?

The very last photons from the surface of our star and the last particles that make up the solar wind

have started their final flight towards the Earth.

No one yet suspects that the heart of our solar system has stopped functioning.

8 to 9 minutes later and the sky suddenly turns black.

Darkness descends upon the entire planet.

No matter whether at the moment it's the deep dark of midnight

or a bright sunny noontime at your location,

you can quickly and easily see the difference.

The stars are now all clearly visible against the sheer black backdrop of the sky.

The Moon is not visible at all since there's no longer any sunlight were it to reflect

A moment before the onset of the all and shrouding darkness

bright Northern Lights may appear

due to changes in the magnetic field around the Earth

and the disturbances in the ionosphere.

The most dreadful consequence of all

is the complete and utter cessation of the process of photosynthesis

resulting in plants and cyanobacteria no longer producing oxygen.

This will soon lead to, how shall we say it,

difficulties for every living being.

After an hour, true panic reigns over the heretofore day times side of the earth.

Power and communication outages propagate across the entire planet.

Temperatures everywhere drop by a several degrees

and the Earth surface begins to slowly cool.

But from the inside the planet is still heated by its molten core.

24 hours in, dawn has not and will not arrive.

Panic and chaos are enveloping the entire world

State authorities have almost zero control over the situation.

Humankind is trying to figure out what the hell happened

while coping with massive power and water supply outages.

The temperature on the surface falls to between 5° to 7 °C

That's about 41° to 45 °F

and has now decreased by about 15° to 20 °C.

That's a drop of about 30 °F.

Some species of plants and microorganisms begin to die.

The inhabitants of the ocean for the time being

feel almost no changes.

After 7 days, it's still dark.

The average temperature on earth is now -17 °C.

That's about 1 °F.

In areas where there are tectonic faults,

it's still warm.

Thanks to geothermal energy

not letting the surface freeze over.

Most plants have already died due to cold or lack of light.

Herbivorous and heat loving animals also begin to die.

In the oceans, phytoplanktons begin to die as well.

The inhabitants of shallow waters

suffer tremendously from the cold

and the surface of the ocean is beginning to turn to ice.

By now, scientists and other individuals have realized

what has happened and rushed to organize and equip shelters.

One month in and the Earth is continuing to cool.

The average temperature on the surface

is now about -30 °C.

That's -22 °F.

And almost the entire planet is now coated with ice.

Virtually all plants and cyanobacteria have perished.

Some species of trees, especially conifers, are still alive.

But with the lack of sunlight,

even they are not producing oxygen.

In fact, most of the earth living things have died.

But..

some bacteria still carry on with their normal life activity.

Most of the remaining life on earth

is now found only near geothermal springs and under water.

Interestingly, the layer of ice on the surface of the ocean

slows down their cooling.

And in the areas of oceanic tectonic faults

and geothermal sources, the water is still warm.

Obviously being naturally heated.

But even in the ocean

the drama of a mass extinction event

begins to unfold.

One year in and the surface of the Earth and the oceans

are covered with a thick layer of ice.

According to professor David Stevenson at CalTech

the temperature on the surface of the earth

should drop to about -40 °C and that's the same in Fahrenheit.

Life endures now only deep in the earth oceans,

and perhaps some groups of humans

might be able to survive on the surface of the planet

in places like Iceland and other areas with large amounts of geothermal activity.

Professor Stevenson believes that the Earth

will continue to cool for another several thousand years.

Until the surface temperature reaches approximately -160 °C.

That's about -256 °F.

At that point, life on the planet

in the usual sense of the word

will simply become impossible.

And let's not forget about the gravity of the Sun.

After all, it's unlikely that the Sun could suddenly go out

without losing its gravitational pull.

If the Sun ceases to hold the planets

and other celestial bodies in their orbit

then the planets and asteroids will simply fly away into outer space.

Some of them possibly even colliding with one another.

The Earth for one will soar out into deep space

where it could get bombarded with asteroids, comets and radiation

collide with another planet

or even some day end up in the gravity well of a black hole.

There's also a very small possibility that

after wandering through space for a very long time,

the Earth would be able to integrate

into another stellar system and find a new sun.

In the end, however,

it's important to realize that this scenario is just a fantasy.

Or rather a thought experiment of sorts.

As for the real future of our star,

in a couple of billion years

the sun will swell and turn into a red giant.

Our star will swallow Mercury and Venus

and Earth and Mars will become heated up to several thousand degrees.

In five billion years,

the Sun will explode and throw off its outer envelope.

Leaving at the center of the Solar System,

a gradually cooling stellar core.

A white dwarf around which will orbit

whatever remains of the Solar System after the explosion.

Concerning humankind, its fate remains unknown

Hopefully by that time

we'll be able to fly to other planets and star systems.

But that is a story for another day.