Hubble Space Telescope’s successor, James Webb Space Telescope, has an uplifting mission. Besides observing some of the most distant events and objects in the universe, understanding the formation of stars and planets, and direct imaging of exoplanets and novas, JWST has an extended mission to find habitable worlds. Habitable for humans, thus showing signs of water.
The mission of James Webb Space Telescope
To find signs of water on other planets scientists look for water vapor in their atmospheres. James won’t observe randomly any star coming its way, but binaries of brown dwarfs. When orbiting around the host planet, the exoplanet allows telescopes, such as JWST, the opportunity to make sensitive observations due to the way light is filtered and bent. The procedure is called transmission spectroscopy.
Astronomical spectroscopy is a type of remote spectral sensing. The objects and samples of interest being so distant from the Earth, electromagnetic radiation is the only resource available to measure them. Astronomical spectra contain both absorption and emission spectral information.
Absorption spectroscopy has been particularly important for understanding interstellar clouds and determining that some of them contain molecules. Absorption spectroscopy is also employed in the study of extrasolar planets. Detection of extrasolar planets also measures their absorption spectrum and allows for the determination of the planet’s atmospheric composition, temperature, pressure, and scale height, and hence allows also for the determination of the planet’s mass.
Clouds on exoplanets might impair JWST’s observations
Clouds, either icy or vapors, will obstruct James’s surveillance, a study says. The study leader Thaddeus Komacek, from The University of Chicago, and his team simulated transit spectra for planets with different rotation rates, incoming starlight, surface pressure, radius, to see if the clouds impair the telescope ability to detect water vapor — and they do.
James Webb Space Telescope will need to observe 10–100 times more transits of the exoplanet to detect the atmospheric water vapor. Luckily, it isn’t JWST’s only mission. He’ll have a lot on its plate with or without the clouds.