ACTIVITY 174:You're going to read an article about an
unexplained mystery. For questions 1-6, choose whether the statements are
TRUE or FALSE. Then check the
THE SIBERIAN MYSTERY
At 7.17 a.m., local time, on 30 June 1908 a fireball of
devastating proportions struck Earth in the valley of the Tunguska river, a
remote part of northern Siberia. Its blazing heat flattened an area the size
of Leningrad, melting metal objects and incinerating herds of reindeer.
Foliage was ripped from trees, the blast uprooting them like matchsticks.
Nomads were lifted bodily from the ground and their tents flung away in the
violent wind. A farmer sitting on his porch 60 kilometres
away described it:
'There appeared a great flash of light. There
was so much heat that I was no longer able to remain where I was
– my shirt almost burned off my back. I saw a huge fireball that
covered an enormous part of the sky. I only had a moment to note
the size of it. Afterwards it became dark and at the same time I
felt an explosion that threw me several feet from the porch. I
lost consciousness for a few moments and when I came to, I heard
a noise that shook the whole house and nearly moved it off its
Whatever caused the Tunguska explosion, it wasn't a meteorite,
it seems. The controversy about possible causes has split
investigators into those who believe that it was a comet (a kind
of dirty cosmic snowball consisting of chunks of frozen gases
with meteoritic material and dust mixed in), and those who
prefer a more fanciful explanation. Findings from many sources
now strongly favour the comet, but the last word has certainly
not been said. The alternative theories are in any case
provocative and appealing enough to be worth considering.
The area which was hit was quite densely populated.
The heat was so intense that it burned or melted almost everything in the area.
The farmer was able to regain consciousness after the explosion took place.
The light lit up a huge area for hours.
Investigators fall into two categories: those who believe a meteorite caused the explosion, and those who favour some other explanation.
One of the theories suggests that the area was hit by a comet.