NASA Discovers 72 New Asteroids Near Earth

"NEOWISE detects asteroids and comets, both near to Earth and further away, in the asteroid Main Belt for example, using infrared light. Because we look in the thermal infrared, the part of the spectrum where these small solar-system bodies are re-emitting the light they absorbed at other wavelengths, we can detect some of the darkest ones more easily than ground-based observatories, which look at their reflected light from the Sun. We can also get a better idea of the sizes, based on how much infrared light they re-emit. This way we detect and characterize Near Earth Objects that we may want to visit in the near future, and find new ones that may present impact risks as well as opportunities for exploration. NEOWISE has detected over 500 NEOs to date, including more than 81 discovered."