An asteroid, half the size of a football field, misses Earth by 15 minutes today.
Asteroids this size hit the Earth, on average, once every 800 years. The last one similar to 2012 DA14 hit Tunguska, Russia, in 1908 leveling 800 square miles of forest. If an asteroid this size hit Houston it would wipe us out; we are 627 square miles in extent. I often get asked if a Tsunami could ever hit our shore line. The only way this would happen is if an asteroid landed in the Gulf of Mexico.
According to the European Space Agency, the meteorite that hit Russia overnight is unrelated to the asteroid that will miss Earth later today. Information is still coming in but if I were to guess, this meteorite is probably the size of a room in your home. By comparison, the asteroid that will miss the Earth is half the size of a football field.
Here is one of the videos from the event:
So, what's the difference?
A meteor is a small piece of space dust, about the size of Grape Nuts cereal with the same texture, which burns up as it hits the Earth's atmosphere. A meteorite is a larger piece of space rock that impacts the Earth, like the Russian meteorite that hit overnight. Another name for an asteroid is a "small planet," so you get the idea how large these can be. The one that misses the Earth today is half the size of a football field. Here is a good video of how close it gets: