A composite of images from NASA’s Deep Space 1 spacecraft shows features of comet Borrelly’s nucleus, dust jets escaping the nucleus and the cloud-like “coma” of dust and gases surrounding the nucleus. False colour is used to reveal details of the jets and coma (Image: JPL / NASA)
SWATHES of dark comets may be prowling the solar system, posing a deadly threat to Earth.
Hazardous comets and asteroids are monitored by various space agencies under an umbrella effort known as . The vast majority of objects found so far are rocky asteroids. Yet UK-based astronomers Bill Napier at Cardiff…
