Recognizing asteroids is difficult for a number of causes. Firstly, there’s the matter of dimension. Asteroids over a kilometer in dimension do exist and are normally comparatively straightforward to see as a result of they’re so huge, whereas small asteroids of underneath 100 meters throughout do not pose a danger as they might fritter away in Earth’s environment. However these asteroids within the center vary, from 100 meters to 1,000 meters throughout, may trigger large injury in the event that they hit the planet however are tough to detect.
Another excuse it is exhausting to identify threats is that they will come from completely different instructions, so we must be trying throughout the entire sky to identify them. In addition to asteroids, which usually originate within the asteroid belt, there’s additionally the problem of comets. These comprise ice versus rock, and sometimes originate from the Oort cloud, which makes their paths exhausting to foretell.
A devoted telescope like NEO Surveyor will be capable of detect two-thirds of asteroids which are bigger than 140 meters throughout in addition to be capable of observe extra comets to find out how a lot of a menace these is likely to be.
Lastly, asteroids might be made of various types of rock and so might be lighter or darker. The lighter asteroids mirror extra gentle and are simpler to see, whereas the darker ones are even tougher to identify. That is why NEO Surveyor seems to be within the infrared, so it may possibly see the warmth given off by the asteroids as a substitute of counting on seen gentle. Because the asteroids get nearer to the solar they warmth up, and this warmth makes them seen within the infrared.