steve cross loves music and science

Credit: Google/NASA Meteor Watch

California and Nevada residents may have been terrified by the loud sonic boom that shook their houses Sunday morning, but now that we know what caused it, they should feel privileged to have experienced such a rare event. We now know that the cause was a fairly large meteor that entered our atmosphere with the energy equivalent to a 5-kiloton explosion. I’ve read other estimates for the energy, but that is the official number from NASA’s Meteoroid Environments Office. That puts it entering our atmosphere at a blistering speed of over 33,000 mph. This meteor was about the size of a minivan, so it was easily visible during the daylight, and that fact that it caused a massive sonic boom means that it made it all the way down to the troposphere, the lowest level of atmosphere, or the level in which clouds and weather occur. Most meteors are much MUCH smaller, and even if they did cause a sonic boom, they burn up far too high in the atmosphere for us to hear it, not to mention that that the air up there is much thinner and doesn’t carry sound waves as well. Because of this meteor’s size and density there’s a decent chance that some fragments of it may have made it to the ground. Once they hit the ground they’re called meteorites, and there are people who make it their living to hunt for them. The rarity of this event is why I think the people who got to see it or hear it are very lucky. I’d give anything to witness something like that. Meteors of this size only occur about once a year, and the simple fact that earth is about 75% covered in water means that us land-dwellers only have a 25% chance of seeing one when they do hit. (Other sources: Universe Today and Discovery News)