Jakarta, CNBC Indonesia – For 90 years there has been a mystery surrounding the comet with a green shadow. Finally, the latest research managed to explain the mystery.
Oftentimes, the Kuiper Belt and Oort Cloud throw galactic snowballs or comets made up of ice, dust, and freshly formed remnants of the solar system. The object underwent a colorful metamorphosis as it crossed the sky.
Even most comet heads turn bright green. The color gets lighter as it approaches the sun.
But it becomes a mystery when the green shadow turns out to be gone just before one or two tails are left behind the comet. The mystery has even been studied by various studies for 90 years.
In 1930, physicist Gerhard Herzberg had a theory that the phenomenon was the result of sunlight destroying diatomic carbon but the theory was difficult to test. Then 90 years later, a new study led by UNSW Sydney published 20 December 2021 also seeks to uncover the theory of decades ago.
“We have proven the mechanism by which dicarbon is broken down by sunlight,” explained professor of chemistry at UNSW Science and senior author of the study, Timothy Schmidt, quoted from Scitechdaily, Thursday (12/23/2021).
“This explains why the green coma, the hazy layer of gas and dust surrounding the nucleus, shrinks as a comet approaches the Sun and why comet tails are not green.”
Dicarbon is highly reactive and is what gives comets their green color. It is made up of two carbon atoms stuck together and can only be found in highly energetic or low oxygen environments. It occurs like stars, comets, and the interstellar medium.
This material will not be visible on the comet until it is close to the Sun. As the comet begins to warm from the Sun, the organic matter in the ice core evaporates and moves into a coma.
Next sunlight breaks down the larger organic molecules and carbon dioxide appears. While the green color disappears before it reaches the tail, because as the comet gets closer to the sun, extreme UV radiation breaks down the dicarbon molecules and destroys them before they can travel far from the nucleus.
Responding to the 1930 findings, the study’s lead author and former UNSW Science Honors student, Jasmin Borsovsky said it was remarkable to get to the level of detail of the mechanism by which this occurs. Next 90 years later, the new research team was able to what happened.
“Herzberg was an outstanding physicist and went on to win the Nobel Prize in Chemistry in the 1970s. It’s great to be able to prove his theory,” says Borsovsky.