A new haul of comets around distant stars has been unveiled, more than doubling-up the number we know of. Comets such as Halley's Comet, which makes an extensive, oval path passing near the Sun every 75 years, make themselves known through their long tails of gas and debris that comes off as they approach their host stars. The finding of more and more comets also raises the possibility that comets could play a vital role in delivery services.
The new study helps illuminate the interaction between those planets and the debris discs from which they came and in turn help to explain how our own Solar System formed. The first such exocomet was exposed in 1987 but since then only three more had been found. In our Solar System, comets come from the Kuiper belt, a disc of debris beyond the orbit of Neptune, or from the Oort cloud, yet larger and more distant debris disc.