What NASA can do to track near Earth objects!
Last Asteroid Impact
The last asteroid impact was in Chelyabinsk, Russia on Feburary 15, 2013. It injured about 1,100 people, and at least 200 of them were children mostly hurt by shards of glass. Even though there were almost no deaths the asteroids could've killed about as many as it had injured.
We need to be prepared!
The way to be prepared for an asteroid impact is to find a way to track the closest asteroids. So if one is about to hit we can estimate where it's going to hit and evacuate that place sono one gets hurt.
How would we track them?
I think the best way to track those asteroids threatening to impact Earth is to send some small space probes to track those asteroids or to invent a telescope that can see those small (compared to other ones) asteroids.
How do scientists find asteroids?
Scientists find asteroids using telescopes and math. They use the telescopes to look for asteroids and when they find one they use math to predict the path that it will take. The path of a space object is very predictable so asteroids can figure out the path that it will approximately take.