We are fatally mistaken in studying the Webb data. What will this lead to and is it possible to fix everything

The James Webb Space Telescope shows the universe with impressive, unprecedented clarity.

Ultra-sharp infrared vision of the observatorycuts through cosmic dust to illuminate some of the earliest structures in the universe, hidden stellar nurseries and spinning galaxies hundreds of millions of light-years away.

What are the tasks of Webb?

In addition, Webb will receive the most comprehensiveunderstanding of the objects of the Milky Way, namely some of the 5,000 planets found in the galaxy. Astronomers are using the precision of the telescope's light analysis to decipher the atmosphere surrounding some of these nearby worlds. The properties of their atmospheres will be the key to understanding how the exoplanet formed and whether it has signs of life.

What is the problem?

Massachusetts Institute of Technology employeesInstitute conducted a new study. The scientists suggest that the tools that astronomers typically use to decode light signals may not be good enough to accurately interpret the new telescope's data. In particular, opacity models - tools that model the interaction of light with matter depending on its properties - may need significant reconfiguration to match the accuracy of Webb's data.

If these models are not finalized, then the propertiesplanetary atmospheres, such as their temperature, pressure, and elemental composition, can differ by an order of magnitude. This means that scientists are fatally wrong in their calculations.

Webb telescope illustration, NASA

There is a scientifically significant difference betweenthe content of a compound such as water, in an amount of 5% and 25%, which modern models cannot distinguish. The model that NASA scientists use to decipher the spectral information does not match the accuracy and quality of the data obtained from the James Webb telescope. As the scientists noted, it is necessary to solve the problem of opacity.”

What is opacity?

Opacity is a measure of how easilyphotons pass through the material. As you know, photons of certain wavelengths can pass directly through the material, be absorbed or reflected back. It all depends on whether they interact with certain molecules within the material and how this happens. This interaction also depends on the temperature and pressure of the material.

The opacity model works based onvarious assumptions about how light interacts with matter. Astronomers use it to obtain certain properties of a material given the spectrum of light emitted by the material. In the context of exoplanets, the opacity model allows one to decipher the type and abundance of chemicals in a planet's atmosphere based on the light that reflects off it and is captured by a telescope.

What's going on now?

The current modern opacity model,compared to a classic language translation tool at MIT, "works decently." It normally deciphers the spectral data obtained by telescopes such as the Hubble Space Telescope.

First photo of JSWT, NASA

“So far, with this Rosetta stone, everything is inokay," the researchers wrote. But now that scientists are taking the "next level" with Webb's ultra-precise tools, the current translation process "will not capture the important subtleties." For example, those that distinguish a habitable planet from an unsuitable one.

What have the scientists done?

In a new study, MIT researchers looked for,what atmospheric properties the model will get if it is adjusted. The goal is to allow certain limitations in understanding how light and matter interact. As a result, scientists created eight such "perturbed" models.

They then supplied each model, includingreal version, "synthetic spectra". We are talking about the patterns of light that scientists have modeled. They are similar to the accuracy that the James Webb telescope could fix.

What did the scientists find out?

It turned out that, based on the samelight spectra, each perturbed model gives large-scale predictions of the properties of the planet's atmosphere. Based on the analysis, the scientists concluded that if the existing opacity models were applied to the light spectra obtained by the Webb telescope, they would reach a certain “wall of accuracy”. In simple terms, they will not be sensitive enough to find out the actual temperature of the planet (300 or 600 degrees Kelvin, 26.85 ° C - 326.85 ° C) and what gas occupies 5% or 25% of the atmospheric layer.

This difference is important so that scientists can limit the mechanisms of planet formation and reliably identify biosignatures.

The team also found that each model alsoprovided a “good fit” to the data. This means that even if the perturbed model provided the wrong chemical composition, it generated its light spectrum. It was close enough to "correspond" to the original.

What's the bottom line?

There are enough parameters to tweak, even with the wrong model, to get a good match. This means that it is impossible to know for sure that the model is wrong.

Scholars have come up with several ideas about howimprove existing opacity models. For example, more laboratory measurements and theoretical calculations need to be made to refine assumptions about how light and different molecules interact. Collaboration of scientists from different fields is also necessary. In particular, between astronomers and specialists in spectroscopy.

Much could be done if one knew perfectly how light and matter interact.

Read more:

Mysterious 'blue goo' at the bottom of the sea baffles scientists

Developed generator for wind farms without expensive magnets

Look at a phenomenon that is simply impossible on Mars

Hi-Tech translated and adapted Jennifer's articleChu "Study: Astronomers risk misinterpreting planetary signals in James Webb data", published in MIT News, a website covering news about MIT research, innovation, and teaching. The original article can be found at the link.

Cover illustration: Thibaut Roger, Thibaut Roger
Copyright: © CC BY-NC-SA 4.0