James Webb tracks a crucial but untraceable carbon molecule for decades

Decades ago, researchers speculated that the carbon molecule CH3+ plays an important role in creating a component critical to life: carbon-containing molecules. There was just one problem: searches for the cosmic CH3+ were fruitless. But that has changed now…

in the paper nature Researchers announce that they have detected CH3+ in a protoplanetary disk, located about 1,350 light-years from Earth. It is based on observations made with the very powerful James Webb Space Telescope. “The discovery of CH3+ not only proves James Webb’s amazing sensitivity, but also underscores the supposed critical role that CH3+ plays in interstellar chemistry,” said researcher Mary Ellen Martin.

Carbon and life
All forms of life on Earth depend on carbon compounds. No wonder scientists studying the origin of life on Earth and the possibility of life on other planets have an above average interest in the formation and occurrence of carbon compounds in interstellar space, where stars and planets are born. The focus is often on carbon-containing ions, because they can form more complex carbon compounds through reactions with other small molecules – even at the low temperatures of interstellar space.

characteristic
CH3+ is such a molecular ion. And not just anyone. In the 1970s, researchers called it “a cornerstone of interstellar carbon chemistry.” It all has to do with one great feature of CH3+. For example, the ion not only readily interacts with the most common element in the universe: hydrogen, but it readily interacts with other molecules. And so he knows how to initiate the growth of more complex carbon-containing molecules in a way like no other, or so he thought.

a statement
It has therefore been suspected for decades that CH3+ plays a crucial role in the formation of complex organic molecules, or the building blocks of life as we know it. But she remained suspicious. Because researchers failed to detect CH3+ in places where (potentially habitable) stars and planets saw daylight. But that has now changed thanks to James Webb.

protoplanetary disk
James Webb discovered CH3+ in a protoplanetary disk. This is the disk of gas and dust that we find around young stars from which planets can form over time. The disk is located at a great distance from Earth, in the famous Orion Nebula. At the heart of the protoplanetary disk is a young star. It is a red dwarf star with a mass about 10 times smaller than that of our Sun.

puzzle
With the discovery of CH3+, the researchers not only confirm that the ion does indeed play an important role in interstellar chemistry. In passing, they also appear to be solving a decades-old mystery as well. This mystery was born when researchers discovered meteorites in our solar system witnessing that the protoplanetary disk from which Earth and other planets in our solar system were born was bombarded with ultraviolet rays. This radiation must have come from a massive star that was originally a companion to our sun. It is curious that the protoplanetary disk had to withstand a lot of ultraviolet radiation. Because it is believed that ultraviolet radiation has a destructive effect on the formation of complex carbon molecules. However, there is clear evidence that the only planet known with certainty to harbor life (carbon-based) emerged from a protoplanetary disk that was heavily bombarded with ultraviolet light.

Solution
how is that possible? The researchers think they’ve figured it out. The protoplanetary disk in which CH3+ was found also appears to be bombarded by ultraviolet light. But where this radiation was previously mainly associated with the destruction of complex carbon-containing molecules, researchers are now finding indications that it is a somewhat more subtle story. Their study indicates that UV light provides the energy needed to form CH3+. “This clearly shows that ultraviolet radiation can completely alter the chemistry of the protoplanetary disk,” said researcher Olivier Bernier. “UV radiation may, in fact, play an important role in the very early chemical stages of life by stimulating CH3+ production.”

It is easy to explain why CH3+ detection, which is so critical, took so long. Many molecules in protoplanetary disks are being identified using radio telescopes. But CH3+ cannot be seen with a radio telescope. The only way to detect this molecule was with a powerful infrared space telescope. And let’s have that with James Webb for a year now. However, the discovery of CH3+ was not a sprint; Since the signal shown by CH3+ in the infrared had not been observed before, it was not easy to identify the molecule with certainty. A reason for astronomers to seek the help of other scientists. And that turned out to be a golden opportunity, says Martin. “This discovery was only possible because astronomers, designers and spectroscopy scientists joined forces to understand the unique features James Webb had observed.”