The Explosion That Could've Erased a City

Subtitles

On June 30, 1908, a catastrophic

event occurred which, despite

being the largest of its kind

in recorded history, remains largely

unnoticed. An event so catastrophic

that it could have killed millions

of people and wiped many large

modern day cities off the map

in mere seconds. Except this event

occurred deep within the remote

Siberian taiga. This event is

known as the Tunguska event.

At around 7:17 in the morning

of June 30, 1908, Evenki natives

observed an extremely bright bluish-white

object moving slowly downward

toward the horizon. The object

was nearly impossible to look

at glowing brighter than the Sun.

It appeared to have a cylindrical

shape and left a thin white trail

in its path. As it neared the

ground, the object seemed to smudge.

Suddenly there was a bright flash

and a huge column of black smoke

rose into the air emitting flames

of uncertain shapes. People near

the event watched as the entire

landscape around them turned red

and the air became so hot that

it felt as if their clothes were on fire.

A sound of an incredibly strong

wind was heard. Immediately following

came a tremendous shock wave destroying

structures, shattering glass,

and throwing people backward,

some up to 40 meters. Ringing

in the air was a sound akin to

that of artillery fire. Trees

snapped like toothpicks and the

entire forest was uprooted and

flattened to the ground bursting

into flames. Then came a second

shock wave as strong as the first,

and then a third. The shock waves

were felt hundreds of kilometers

away and many people were knocked

unconscious, some for just a few

minutes and others for 3 days.

The peaceful morning had just

been interrupted by one of the

most extreme events in recorded

history.

Quantifying the number of injuries

and casualties from this event

is difficult. More on that in a bit.

However, the Tunguska event caused

at least 3 deaths and an unknown

number of injuries with many people

lying unconscious for hours or

even days. The blast flattened

around 2,150 square kilometers

of forest, an estimated 80 million trees.

This photograph was taken nearly

21 years after the event, yet

the forest has barely begun to

recover.

The shock waves were powerful

enough to knock people off their

feet 600 kilometers from the epicenter

and knock people unconscious nearly

200 kilometers away.

For several nights after the

event, the skies glowed all the

way to Northern Ireland bright

enough to read a newspaper by

after midnight. The glow was likely

caused by particles dispersed

in the upper atmosphere.

It's actually not very easy

to determine what happened or

even how exactly the story goes.

The description given just now

was a compilation of data collected

from interviews with many different

witnesses and is the most likely

storyline. But there are many

inconsistencies and problems with

the data. The people who were

interviewed lived deep in remote

forest, their language didn't

even have a written form before

1931, and they had many superstitions.

These superstitions led them to

avoid talking about dead relatives

or friends, which made it difficult

for interviewers to assess the

casualties from this event. These

superstitions may also have embellished

some of the stories as well, it's

really hard to know. And, of course,

many of these interviews were

recorded decades after the event

occurred. In fact, not until nearly

20 years later, in 1927, was the

first scientific expedition to

the blast site. Some of the stories

were from people who were children

at the time of the event, some

of the stories were from people

hearing what someone else told

them, and the list of likely possibilities

of how stories were exaggerated

or completely distorted just goes

on and on. So, it goes without

saying, that what we think we

know may not be factual at all.

However, there is some data that

is simply undeniable.

The place of the event is still

visibly scared to this day, which

absolutely verifies that this

was an extreme event, otherwise,

the forest would have easily

regrown in the nearly 120 years

since the event. However, there

is almost no evidence of any sort

of explosive or meteor at the

blast site. This has led to two

main theories for the event.

One theory is that a small comet

(composed of things like dust

and ice) vaporized in Earth's

atmosphere, thus leaving no traces

at the blast site. This theory

is further supported by the glowing

skies after the event as the dust

and ice from the meteor could

have been dispersed in the upper

atmosphere. This theory is then

even further supported as the

time of the event was at peak

activity of the Beta Taurids meteor

shower, suggesting that a fragment

of Comet Encke was responsible

for the event. However, this theory

begins to break when some other

data comes into the picture.

The other, and more likely theory

is that an asteroid (composed

of iron) entered Earth's atmosphere

traveling at an insane 27 kilometers

per second, or Mach 80. The asteroid

then exploded mid-air about 9

kilometers above the ground. It's

size has been estimated at around

60 meters in diameter. Whereas

a comet would have likely disintegrated

in the upper atmosphere, an iron

meteor would have been able to

make it into the lower atmosphere,

which would be required for the

tree fall pattern. This theory

is also supported by materials

found in the trees near the blast

site which are found in rocky

asteroids but not comets. Various

other analyses have also supported

the asteroid theory, although

there is really not enough evidence

for either the comet or the asteroid

theory to definitively prove one

as the correct theory.

In early 2013 an event similar

to the Tunguska event occurred

over Chelyabinsk. This event is

the second largest meteor event

in recorded history. It was much

smaller than the Tunguska event

but, importantly, a lot more data

was able to be collected than

from the Tunguska event. This

allowed scientists to compare

the aftermath of the Tunguska

event to a similar meteor event.

It also provided recordings of

what the so called "artillery

fire" after the main blast sounded like.

It sounds exactly like artillery fire.

The Chelyabinsk meteor released

the equivalent of around 450 kilotonnes

of TNT and exploded about 30 kilometers

above the ground. With that energy

and distance there was enough

power from the shock waves to

collapse brick walls and shatter

glass 100 kilometers away. The

Chelyabinsk meteor was smaller,

traveled slower, and exploded

at a much higher altitude than

the Tunguska meteor. If an event

with just 4% the blast energy

and three times the altitude of

the Tunguska event produces results

like this, it makes one wonder

what the result would have been

if the Tunguska event had happened

over a populous city instead of

remote forest. It also makes one

very grateful that our planet

was designed with an atmosphere

to catch most of the meteors before

they become a real hazard.

The Tunguska event is, to this

day, the largest impact event

on Earth in recorded history.