This was the greatest known impact event on Earth since the
1908 Tunguska event. Now, as then, a small asteroid (or huge meteor)
entered the atmosphere and exploded in the air, sending a shockwave
out and down.
This time, an object about 18 meters (54ft) across entered the
atmosphere, again in the Siberia region, at 03:20:33 GMT at a
shallow angle. It seared a luminous path in a Northwestern direction
across the skies of a cold late Winter morning in the Ural Mountain
region. As it encountered denser air the meteor slowed down, with
enormous energy being unleashed upon the rocky body, climaxing
with an extended explosive energy release at some 23.3 km (14.5
miles) altitude over 54.8 degrees N, 61.1 degrees E. This long
brilliant burst peaked in brightness briefly lighting up the region
brighter than sunlight, with people nearby feeling the radiant
heat. The fireball lunged forward when the flash died down enough
to follow the progress in the many videos captured of the event,
with some smaller white hot remnants continuing on as the long
burst region cooled. One larger cloud rose from the site of maximum
energy release, and several smaller 'puffs' further behind sorted
themselves apart and rose from the main smoke trail.
Many videos were made of the entry, and more were made as people
reacted to the sight and went outside to record the smoke trail
for themselves. The arrival of the shock wave from the terminal
burst was thus well documented. A tremendous crashing boom announced
its arrival, with secondary booms going on and on like an explosives
factory accident, car alarms, screams, and cascades of broken
glass heard in the foreground. It took over 2 minutes between
the burst and the arrival of the sound/shock wave, with smaller
trailing pieces shed along the way contributing their own noise
later.
The city of Chelyabinsk, with its grim and eventful history, added
widespread damage by a celestial visitor to its distinction. In
wide regions virtually every window facing the blast had the frames
for multiple windows caved in, glass driven inside and spilling
in front of the buildings. Over 1000 people were cut by flying
glass, and weak structured buildings had their ceilings caved
in across a wide region tens of kilometers across bounded by the
city in its North. The overpressure (beyond the normal 14.6 ish
PSI, pound force per square inch at sea level) arriving suddenly
can do great damage. In this case, about 0.4 PSI worth of force
slammed into the region, in many videos looking almost like atomic
test films of old with doors slammed open, windows smashed and
in one case a large factory losing part of its roof. Indeed, this
blast was of the size range of many nuclear tests, equivalent
to some 440 kilotons of TNT. This is what an 11,000 ton house
sized object making a hypervelocity entry can do.
My digital painting, based on what info I have gathered of
this event, seen from about 10 km altitude looking down on the
city of Chelyabinsk. The maximum burst is just beginning, sending
shock waves that will take over two minutes to reach the ground.
The meteor is traveling sideways from this view with the Sun having
just risen from this altitude well off the left of the field of
view.A mosaic of the region was prepared and used as a texture
map, then the perspective view rendered from this was used as
a template for an entirely original view of the region using recent
satellite photos as a guide, showing the extensive snow cover
etc. The streets are lit with the morning commute although the
lights overall are mainly off. Digital painting Copyright ©Don
Davis
I would like to make an animation, flat screen or fulldome, of
this event. If anyone is interested please feel free to contact
me at DD4SKYART@gmail.com
Below: a compilation of photos of the event re aligned and resized
to provide a rough idea of the relative brightness and detail
differences along the length of the region of maximum energy release.
The further views (left) provide more of an overview, the images
from closer in (right) give more sense of the cooling and billowing
of the fireball.