video - chelyabinsk meteor Flashcards
What is infrasound? How does its analysis provide clues that a meteor may have exploded in the atmosphere?
Infrasound - sound waves too low to hear. Deep base tones = huge amounts of energy, below human hearing. lower sound = bigger explosion
Clues - travel for a long time. low frequency waves circled the world a few times from this blast. The stations with sensitive sensors that detected this were larger waves than ever seen before.
travelled around the earth several times & picked up by multiple infrasound detectors
What makes all the video footage of the meteor especially valuable to scientists?
Size does matter
Estimate the angle of the meteoroid approach
Calculate the speed
In the laboratory, why are the scientists interested in learning about the density of the meteor? The Chelyabinsk meteor fragments were found to be 10% metal and 90% rock. What else did the microscope scans reveal about the meteorite fragments?
Composition of asteroid is important for effects - strength and density is important cause denser stronger ones will fragment lower in the atmosphere vs weak will fragment high
interior is untouched by atmosphere (pressure exceed strength of asteroid)
Meteorite fragments have internal cracks (hitting brick wall when hitting atmosphere therefore exploded). The explosion caused a shockwave to spread out from the point that shattered windows (city).
Considering the massive explosion and shockwave, why wasn’t the damage in Chelyabinsk worse?
Because the meteor was moving at a shallow angle, most of the energy was expended horizontally instead of vertically. Since it came at a shallow angle, the effects were much less.
If it struck at more of a downwards/sharper angle, the effects would have been disastrous. like the Tunguska explosion was much closer to the ground, and it was much more intense, blowing down trees and structures.
What surprising fact about the Chelyabinsk event was indicated by the trajectory model?
It seems like the asteroid hit us, but the truth is, we hit the asteroid.
It crossed Earth’s path, and our planet rolled right over it
Mark’s calibrated photos and trajectory model, we can now tell where it came from and the likely route it took to Earth.
