Study reveals secrets from Comet 46P / WirtANEN

In 2018, Comet 46P / WirtANEN made its closest approach to the Earth on December 16, 2018. Due to the proximity of the holidays, the comet was nicknamed the “Comet de Noël” and exuded an interesting green glow. It spent 7.1 million kilometers from the land, which is the nearest passage he had made to the land for centuries. 

Although 46P / WirtANEN has been gone for years, studying the comet continued. Recently, a study has been published and found that it released an unusually high amount of alcohol since it was adopted by our planet. John Hopkins Scientist Neil Dello Russo said 46P / WirtANEN has one of the highest alcohol-aldehyde ratios measured in any comet so far. According to Russo, this ratio told scientists about how carbon, oxygen and hydrogen molecules were distributed in the early solar system where the comet was formed.

Researchers at the Keck Observatory brought together comet data that revealed another strange feature. As a general rule, as a comet orbits closer to the sun, frozen particles in the heating and boiled core, passing from solid ice to gas, completely circumvent the liquid phase into a process called overrun. The outgassing is responsible for coma, which is the cloud of gas and dust that shines around the core of the comet.

As a comet near the sun, solar radiation pushes part of the coma away from the comet creating the emblematic tail they are known for. The interesting discovery of about 46P / WirtANEN is that Keck’s data display another process in addition to solar radiation heating the comet. The researchers found that temperatures measured for the water gas in the coma did not significantly reduce with the distance of the core, involving a heating mechanism.

A potential explanation is a chemical reaction with the light of the ionizing sun, certain atoms or molecules in the coma near the core, which releases high speed electrons. When these electrons collide with other molecules, they transfer kinetic energy and heat the gas from the coma. Another potential reason is that pieces of ice can come out of the comet. This process was observed in other comets from the past and these pieces of ice may sublimate while they moved away from the core and release energy further in the coma. Scientists continue to study the data collected on the comet to try to reveal more secrets from the comet.