Section+3*

__Detection__
==== The airburst detectors are carried on satellites operating at 38 000km altitude. They detect heat and infrared radiation to detect the comets. The infrared sensors scan the Earth’s disc every 10 seconds at a wavelength of 2.78 microns. ====

__ Protection __
==== The Spaceguard programme is there to find possible ways of destroying comets. Spaceguard is a system of six 2.5-metre telescopes. This will give us much more accurate data about small objects in the solar system and may even give us a warning if a meteor is heading towards Earth.This could save Earth! ====