NASA's Webb Is So Good But We Might Need Improved Planetary Models

NASA's state-of-the-art Space Telescope (JWST) is bringing images of the universe with unprecedented clarity. Astronomers are using this telescope's light parsing precision to decode the atmosphere of the surrounding world.

But it is also not as accurate as predicted. James Webb's method of interpreting data is not as accurate as previously estimated, according to a new press release published by MIT on Thursday.

According to the researchers, the properties of planetary atmospheres, such as temperature, pressure, elemental composition, could be off by an order of magnitude as determined by the telescope. These views of researchers published in a study in Nature Astronomy.

Julian de Witt, an assistant professor in MIT's Department of Earth, Atmospheric and Planetary Sciences (EAPS) and co-author of this study, says there is a scientifically significant difference between a water-like compound being present at 5 percent versus the 25 percent which current models can't differentiate. 

'The model we are using to decrypt the spectral information is not consistent with the accuracy and quality of our existing data from the James Webb Telescope,' says Prajwal Nirola, a graduate student at EAPS. 'We need to step up our research and tackle the problem of ambiguity'.

Researchers say retuning of models is needed to match the accuracy of the James Webb. 'So far, it's doing fine Rosetta Stone,' says de Wit. 'But as we go to the next level with Webb's accuracy, our translation process will prevent us from catching important subtleties, such as distinguishing between habitable and non-habitable planetary bodies.

The researchers put the most commonly used opacity model to the test to see what atmospheric properties the model would acquire if it were changed to assume certain limitations in our understanding of the interaction of light and matter.

Based on their analysis, the team concluded that existing opacity models by the Webb telescope hit an "accuracy wall" where they were not sensitive enough to tell whether a planet's atmospheric temperature is 300 Kelvin or 600 Kelvin, or  Whether a certain gas takes up 5 percent or 25 percent of the atmospheric layer.

"This difference makes sense for us to constrain planetary formation mechanisms and reliably identify biosignatures," Niroula said.

However, all is not lost. The team also found that each model produced a "good fit" with the data that produced a light spectrum from a chemical composition that was close enough, or "fit in," with the original spectrum.

"We found that there are enough parameters to get a good fit, even with an incorrect model, which means you won't know if your model is wrong and which  telling you he's wrong," De Witt explained.

The researchers argued that more laboratory measurements and theoretical calculations are needed to refine the model's assumptions about how light and different molecules interact.

"If we fully know how light and matter interact, a lot can be done," says Niroula. "We know there's enough around Earth conditions, but as we move into different types of atmospheres, things change, and with increasing quality this is too much data, we run the risk of misinterpreting it".