Comets Are Remnants Of The Early Solar System, Study Confirms

Scientists from NASA's Jet Propulsion Laboratory (JPL) have reportedly confirmed that comets are remnants of the early Solar System. Until now, there was a confusion regarding the origin of comets, and whether they were indeed remnants or pieces from collisions later on. The study was led by Björn Davidsson who conducted a research on the history of comets and trans-Neptunian objects (TNOs), those that originated beyond Neptune, in the Solar System.

According to the study, TNOs were created during the first million years of the Solar System and gradually over the next 400 million years they accreted more material. The TNOs left behind remnants in the solar nebula's cold, outer parts, and comets formed from these. Therefore, the highly porous low density comets actually originated from the TNOs and also retained the nebula's oldest materials.  

"Comets do not appear to display the characteristics expected for collisional rubble piles, which result from the smash-up of large objects like TNOs," Björn Davidsson said. "Rather, we think they grew gently in the shadow of the TNOs, surviving essentially undamaged for 4.6 billion years". The research also confirms that comets like Comet 67P/Churyumov-Gerasimenko give an insight into the early Solar System.

According to previous suggestions by scientists, it was believed that water was brought to Earth via comets. However, a research conducted on the basis of information gathered by ESA's Rosetta spacecraft on Comet 67P/Churyumov-Gerasimenko showed that the water on the comet was different from the type found on our planet; therefore the earlier idea was ruled out. However, 67P was found to have certain key ingredients of life suggesting that comets may have kick started the chain of life on our planet in some way. According to ESA scientist Matt Taylor, comets throw light on the planetary construction process and their relation to the present day architecture of the Solar System, therefore they are treasure troves.