The NASA/ESA/CSA James Webb Space Telescope has begun its scientific mission, which includes the atmospheric characterization of transiting exoplanets. Some of the first exoplanets to be observed by Webb have temperatures below 1,000 K (727 degrees Celsius or 1,340 degrees Fahrenheit), which is a regime where atmospheric hazes are expected to form. The optical properties of these hazes, which control how they interact with light, are critical for interpreting exoplanet observations, but relevant experimental data are not available. Now, Johns Hopkins University astronomer Chao He and colleagues have measured the density and optical properties of organic haze analogues generated in water-rich exoplanet atmosphere experiments. Their results offer new tools to study the atmospheric chemistry of exoplanets and will help scientists model how water exoplanets form and evolve.
“The big picture is whether there is life outside the Solar System, but trying to answer that kind of question requires really detailed modeling of all different types, specifically in planets with lots of water,” said Johns Hopkins University astronomer Sarah Hörst.
“This has been a huge challenge because we just don’t have the lab work to do that, so we are trying to use these new lab techniques to get more out of the data that we’re taking in with all these big fancy telescopes.”
“Whether a planet’s atmosphere contains hazes or other particles has a marked influence on global temperatures, incoming levels of starlight, and other factors that can hinder or foster biological activity.”
Dr. He, Dr. Hörst and co-authors ran the experiments in a custom-designed chamber within their lab.
“We are the first to determine how much haze can form in water planets beyond the Solar System,” Dr. Hörst said.
Haze consists of solid particles suspended in gas, and it alters the way light interacts with that gas.
Different levels and kinds of haze can affect how the particles…
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