From KEVIN JONES
With reference to ‘Amateur videos catch a falling meteorite’ (New Scientist,
Science, 12 March), the explanation for the six Hertz variation in light
from the meteorite was given as ‘molten rock dripping off’. However, an
alternative cause of this variation in light output from the fireball could
be periodic satisfaction of the conditions for total internal refraction
of light at the inner surface of the meteorite’s ‘bow shock’. A similar
effect gives rise to the characteristic ‘doublehumped’ light curve produced
by the fireball of an atmospheric nuclear explosion.
Kevin Jones Leeds
