The last couple of months a very rare occurrence has played out for only the second time in human history. The first as recently a 2008.
On the second July a near-earth asteroid was discovered, tracked and found to be likely to make impact with earth as little as 8 hours after its discovery. The predictions were accurate and it entered the atmosphere and exploded violently at 27 km above the earth. Mostly CCTV cameras in Southern Africa captured the spectacular event.
What has made it so unique is not only was it discovered and tracked before entering the atmosphere but bits of it have now been recovered in Botswana. With such a massive explosion (estimated 1 kiloton) at such a height the resultant fine material was swept by high altitude winds so it was quite the detective hunt to figure out where the debris would most likely land and an even more arduous task to find some of it.
After lots of data gathering, calculations, obtaining permission etc. and 5 days in the African bush the first fragment was found.
This is great for scientists because now they have fresh material from outer space and a very good idea of where it came from, by working its trajectory and speed back into the far reaches of our solar system. Good fresh material like this has also been exposed to less weathering and provides great insights into the early solar system.
Our planet has already ground up, melted and recycled many times over material from the earths formation. It is from these time capsules from the asteroid belt that we can get well preserved snippets of what the early solar system and planets were like due to asteroids being from unsuccessfully formed proto-planets and moons. Material that coalesced in the early solar system but never got into clusters large enough to form a planet.