The asteroid that approached Earth today, which NASA has been tracking, is about 45 meters long, which is relatively small for an asteroid.
4. How does this compare to other Earth impacts?
The Earth picks up tons of meteoric debris every day, but big pieces are fairly uncommon, said David Dundee, astronomer at Tellus Science Museum in Cartersville, Georgia.
An object the size of the Russian meteor comes in about once every 50 years, but none has been recorded since 1908, when an asteroid exploded and leveled trees over an area of 820 square miles - about two-thirds the size of Rhode Island - in Tunguska, Russia.
"This is the largest event that we know of that's happened since Tunguska," Campbell-Brown said.
The Tunguska event did not leave a crater. If there are craters as a result of Friday's meteor, they would be very small, resulting from the debris from the midair explosion.
"It's unfortunate that this occurred over a populated area," Campbell-Brown said. Over a desert or ocean, it would have done very little damage.
This is much smaller than the event thought to have wiped out the dinosaur population, she said.
The meteor was moving through space at about 33,000 miles per hour. When it suddenly decelerated above Russia, the energy was converted into heat and sound, which resulted in a shock wave of energy and a sonic boom, Dundee said.
About three years ago, a woman in Cartersville, Georgia, discovered a baseball-sized meteorite in her home, which had flown straight through the roof. It is now at the Tellus Museum, Dundee said.
5. Why shouldn't you touch a meteorite?
As a meteor comes through the atmosphere, it gets very hot, but this thin hot layer quickly cools off. When you find it on the ground, a meteorite is generally acclimated to ambient temperature.
"We advise people not to touch things with their hands because we like to look for trace elements in the meteorites, and if you touch it in your hand, you've contaminated it," Campbell-Brown said.
Meteorites are probably not more radioactive than Earth rocks, and the minerals inside aren't toxic, she said. The biggest reason to not touch them is to preserve the scientific status.