A meteor exploded in the sky above Russia on Friday, injuring hundreds of people and sending fragments falling to the ground in the Ural Mountains. Here’s a look at those objects in the sky…

What’s the difference between a meteor and a meteorite?

Meteors are pieces of space rock, usually from larger comets or asteroids, which enter the Earth’s atmosphere. Many are burned up by the heat of the atmosphere, but those that survive and strike the Earth are called meteorites. They often hit the ground at tremendous speed up to 30,000 km an hour. That releases a huge amount of force.

Experts say smaller strikes happen five to 10 times a year. Large impacts such as the one in Russia are rarer but still occur about every five years. Most of these strikes happen in uninhabited areas where they don’t cause injuries to humans.

What caused the damage in Russia?

Alan Harris, a senior scientist at the German Aerospace Center in Berlin, said most of the damage would have been caused by the explosion of the meteor as it broke up in the atmosphere. But by the time the remaining fragments hit the ground they would have been too small to cause significant damage far from the site of impact, he said.

Was there any link to the asteroid fly-by that took place later on Friday?

No, it’s just cosmic coincidence.

When was the last comparable meteorite strike?

In 2008, astronomers spotted a meteor heading towards Earth about 20 hours before it entered the atmosphere. It exploded over the vast African nation of Sudan, causing no known injuries. The largest known meteorite strike in recent times was the “Tunguska event” that hit Russia in 1908. Though bigger than the one that hit Russia on Friday, it didn’t injure anyone. What can scientists learn from Friday’s strike?

Some meteorites can be very valuable, selling for up to $670 (Rs. 36,000) per gram depending on their exact composition. Because meteors have remained largely unchanged for billions of years unlike rocks on Earth that have been affected by erosion and volcanic outbreaks, scientists will study the fragments to learn more about the origins of matter. Harris, of the German Aerospace Center, says some meteorites are also believed to carry organic material and may have influenced the development of life on Earth.

SOURCE : THE HINDU