The 46P/Wirtanen comet made its closest approach to our planet back in December 2018. Since it passed by Earth during the holiday season, it was given the moniker of the “Christmas Comet” and it had an intriguing green glow. During its flyby, it reached within 7.1 million miles of the Earth which is the closest pass it has made to the planet in centuries.

While 46P/Wirtanen has gone past Earth many years ago, a lot of studies have been conducted on it ever since. Recently, a new study found out that the comet was releasing a very high amount of alcohol when it passed by Earth.

Comet has some odd characteristics

John Hopkins scientist Neil Dello Russo said the comet packs the highest alcohol-to-aldehyde ratios measured by any comet so far. This ratio allows scientists to determine how carbon, hydrogen, and oxygen molecules were distributed in the early solar system where the comet formed.

Researchers at the Keck Observatory found data on the 46P/Wirtanen that showed another odd characteristic. As a comet revolves closer to the sun, frozen particles in the nucleus boil and become gas from solid ice form, bypassing the liquid phase completely; this process is known as outgassing. The process is also responsible for a coma, which is the cloud of gas and dust that glows around the nucleus of a comet.

Heating mechanism observed

As a comet approaches the sun, solar radiation forces some part of the coma away from the comet, resulting in a tail. In the data from Keck, the comet shows another process besides solar radiation heating the comet. Scientists found out that temperatures for water gas in the coma did not drop significantly with distance from the nucleus, meaning there’s a heating mechanism.

One explanation could be a chemical reaction with sunlight ionizing some molecules in the coma near the nucleus, releasing high-velocity electrons. When those electrons collide with molecules, some kinetic energy is transferred and the water gas is heated.