Starship Asterisk*

These Webb images show a part of the Orion Nebula known as the Orion Bar. The largest image, on the left, is from Webb’s NIRCam (Near-Infrared Camera) instrument. At upper right, the telescope is focused on a smaller area using Webb’s MIRI (Mid-Infrared Instrument). At the very center of the MIRI area is a young star system with a protoplanetary disk named d203-506. The pullout at the bottom right displays a combined NIRCam and MIRI image of this young system. (Credits: ESA/Webb, NASA, CSA, M. Zamani (ESA/Webb), and the PDRs4All ERS Team)

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A team of international scientists has used NASA’s James Webb Space Telescope to detect a new carbon compound in space for the first time. Known as methyl cation (pronounced cat-eye-on) (CH_3⁺), the molecule is important because it aids the formation of more complex carbon-based molecules. Methyl cation was detected in a young star system, with a protoplanetary disk, known as d203-506, which is located about 1,350 light-years away in the Orion Nebula.

Carbon compounds form the foundations of all known life, and as such are particularly interesting to scientists working to understand both how life developed on Earth, and how it could potentially develop elsewhere in our universe. The study of interstellar organic (carbon-containing) chemistry, which Webb is opening in new ways, is an area of keen fascination to many astronomers.

CH_3⁺ is theorized to be particularly important because it reacts readily with a wide range of other molecules. As a result, it acts like a “train station” where a molecule can remain for a time before going in one of many different directions to react with other molecules. Due to this property, scientists suspect that CH_3⁺ forms a cornerstone of interstellar organic chemistry.

The unique capabilities of Webb made it the ideal observatory to search for this crucial molecule. Webb’s exquisite spatial and spectral resolution, as well as its sensitivity, all contributed to the team’s success. In particular, Webb’s detection of a series of key emission lines from CH_3⁺ cemented the discovery. ...

• Nature (online 26 Jun 2023) DOI: 10.1038/s41586-023-06307-x