The James Webb has a problem: it’s too good for astronomers

The James Webb has a problem: it’s too good for astronomers

Over the past few months, it has become abundantly clear that the James Webb Space Telescope does exactly what it was intended to do: show the Universe as we have never seen it before, with detail, depth, and precision that astronomers have previously only been able to do. Sound. Unknown galaxies and on the very edge of the Big Bang; the birth of the first stars; atmospheres of planets in which to search for life; dreamlike landscapes that reveal delicate details where before there were only blurs and spots of color… But that, according to a team of researchers from MIT (Massachusetts Institute of Technology), could be precisely the problem: the data provided by the telescope is much more accurate than the models astronomers use to interpret them. In other words, scientists’ current analytical tools are not up to par with James Webb and therefore fail to extract the full potential of their data. It would be comparable to trying to watch a high-definition movie on an old black-and-white TV from the 1960s: the images on the screen would have nothing to do with the original. Related News standard No The Webb and Hubble telescopes simultaneously capture NASA’s impact on an asteroid Judith de Jorge standard Yes The James Webb reveals the oldest star clusters in the Universe José Manuel Nieves For this reason, say the authors of the study, many Scientists could be drawing conclusions that do not correspond to reality, with a margin of error of up to an order of magnitude. That is, they could be misinterpreting what the telescope is seeing. The worrying study was published a few days ago in ‘Nature Astronomy’. A ‘precision wall’ The authors call the problem a ‘precision wall’ and predict, for example, that properties of planetary atmospheres observed by Webb, such as their temperature or composition, could be widely out of step with the researchers’ calculations. . “There is a scientifically significant difference -explains Julien de Wit, from the Department of Earth, Atmospheric and Planetary Sciences at MIT and co-director of the study- between saying that a compound such as water is present at 5 percent when in fact it is it’s at 25 percent, something current models can’t differentiate.” “Currently -adds Prajwal Niraula, first author of the study- the model we use to decipher the spectral information is not up to the precision and quality of the data we have from the James Webb telescope. We need to up our game and tackle the opacity issue together.” Opacity model Opacity refers to the ease with which photons pass through a given material. Depending on their wavelengths, for example, photons can pass directly through a material, or be absorbed or reflected by it. An opacity model therefore works on the basis of several assumptions of how light interacts with matter. Astronomers use these models to deduce certain properties of a material, based on the spectrum of the light it emits. In the context of exoplanets, an opacity model can decipher, from the light from the planet captured by the telescope, the type and abundance of chemicals in the atmosphere. Interior of the Orion Nebula NASA, ESA, CSA, PDRS4ALL ERS TEAM According to De Wit, the current state-of-the-art opacity model, which he likens to a classical language translation tool, has done a more than decent job of decoding data spectral images taken by instruments such as the Hubble Space Telescope. But with James Webb the story changes completely. “So far – says the scientist – this ‘Rosetta stone’ has worked well. But now that we’ve gone to the next level thanks to Webb’s precision, our ‘translation’ process will prevent us from capturing important subtleties, such as those that make the difference between whether or not a planet is habitable.” The models put to the test In his study, De Wit and his colleagues decided to put the most widely used opacity model to the test. They made up to eight versions of it, with different intentional limitations on how light interacts with matter, and then fed each version precision patterns of light similar to what James Webb would capture. In this way, they managed to get each ‘perturbed model’ to generate its own predictions about the properties of a planet’s atmosphere. The conclusion was that if existing opacity models were actually applied to the light spectra taken by the Webb telescope, they would hit a ‘precision wall’. That is, they would not be sensitive enough to know if a planet has an atmospheric temperature of 300 Kelvin or 600 Kelvin, or if a certain gas makes up 5 or 25 percent of an atmosphere. In Niraula’s words, “an important difference so that we can constrain planetary formation mechanisms and reliably identify biosignatures.” In their study, de Wit and colleagues raise some ideas about how to improve existing opacity models, including the need for more laboratory measurements and theoretical calculations to refine the models’ assumptions about how light interacts with various molecules, as well as collaborations. between disciplines and, in particular, between astronomy and spectroscopy. “In order to correctly interpret the spectra of the various exoplanetary atmospheres -says Iouli Gordon, a physicist at the Harvard-Smithsonian Center for Astrophysics and another of the authors of the article-, we need to carry out an extensive campaign for new measurements and calculations of relevant molecular spectroscopic parameters. These parameters will then have to be implemented in due time in the reference spectroscopic databases and, consequently, in the models used by astronomers”. MORE INFORMATION Noticias No The Webb captures the best image of Neptune’s rings in decades. The matter. We know that pretty well with conditions on Earth, but as soon as we move into different types of atmospheres, things change, and that’s a lot of data, with increasing quality, that we run the risk of misinterpreting.” .


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