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.