Final answer:
A comet of similar size to a stony asteroid would likely explode at a higher altitude in Earth's atmosphere due to its lower density and fragility.
Step-by-step explanation:
According to Scientist 2's viewpoint, compared to the altitude at which a stony asteroid would have exploded in Earth's atmosphere, a comet of similar size would most likely have exploded at a higher altitude. This inference is made based on the understanding that comets tend to be composed of ice and dust, hence they have a lower density compared to stony or metallic asteroids. Less dense objects, such as comets, are more fragile and likely to disintegrate at higher altitudes due to the reduced atmospheric pressure, as stated in the passage that mentions objects that are "smaller or more fragile" dissipating their energy at high altitude.