One of the best ways to find extraterrestrial life is to study the atmospheres of nearby stars, a role JWST It was designed for. However, even the best telescope is useless if the information it provides is misinterpreted, and one team of astronomers fears that is what will happen.
Life has changed Earth’s atmosphere, releasing molecular oxygen and resulting in ozone and absorbing most of the carbon dioxide. Planets with abundant life may not accurately replicate our combination of gases, but astrobiologists hope to find signatures distinct enough to tell the world which life unites from one mostly or completely dead.
The problem, according to Dr. Julian de Wit of the Massachusetts Institute of Technology, is that we risk overestimating the accuracy with which we can calculate molecular abundance from the JWST data. In new research, de Wit and co-authors explain why this may lead to wrong conclusions about this very important question.
Du Wit said in statement.
We can study the atmospheres of other planets by observing what happens to the light passing through them. Any gas will absorb electromagnetic radiation with characteristic wavelengths. When the spectrum of light from a farther source is diminished at those wavelengths, this means that the gas in question must be present there.
However, the amount of gas is just as important as its presence. Astronomers use what they call the opacity model to translate the opacity at certain wavelengths into estimates of gas abundance. The authors argue that the best opacity model developed to date was able to process the limited data Hubble could provide about atmospheric absorption, but not what we’re starting to get from the JWST. Huge telescopes such as the Extremely Large Telescope (ELT) Currently under construction In Chile they will have similar problems.
De Wit and co-authors say this is not just speculation. They generated spectra that JWST might produce while observing a planet, then created eight “disturbed copies” and fed them all into the model. The model could not discern whether the planet was at a temperature of 27°C (80 .).°F) from sub-Venus 300°C (572°F), whether the atmospheric pressure is similar to or twice that of the Earth, nor limit the abundance of gases to a factor of five.
“Now that we’re taken to the next level with Web resolution, our translation process will prevent us from discovering important minute details, such as those that make the difference between a planet being habitable or not,” de Witt said.
In keeping with the adage “It’s not what you don’t know that gets you in trouble. It’s what you know for sure isn’t,” the biggest problem may be the false sense of confidence that astronomers may develop. “We’ve found that there are enough parameters to adjust, even with a wrong model, to get a good fit, which means you won’t know your model is wrong and what it tells you is wrong,” De Witt explained.
Few things would harm confidence in science more than astronomers’ announcement of the discovery of a not only habitable, but inhabited planet, before that claim needed to be retracted.
Thus, the first message of the paper is to take care to explain what comes out of the model. The paper also offers some ideas for creating better models, but neither De Wit nor the co-authors have a superior version ready to go. Therefore, we will need to measure and compare a lot of planetary atmospheres with JWST, rather than jumping to conclusions about the first results we get.
“There is a lot that can be done if we know exactly how light and matter interact,” said MIT graduate student Prajwal Niraula. “We know that well enough about Earth conditions, but once we move into different types of atmosphere, things change, and that’s a lot of data, as quality increases, we risk misinterpreting it.”
The study was published in natural astronomy.