NASA’s James Webb Space Telescope has identified water in the atmosphere of a hot, puffy gas giant planet circling a Sun-like star over a thousand light years distant, the US space agency said on Wednesday.
According to NASA, the observation is the most thorough of its kind to date, proving Webb’s unmatched ability to analyse distant atmospheres. WASP-96 b is one among the Milky Way’s more than 5,000 known exoplanets.
It is located around 1,150 light-years distant in the southern-sky constellation Phoenix, and it represents a form of gas giant that has no direct equivalent in our solar system, according to the organisation.
WASP-96 b is far puffier than any planet circling our Sun, with a mass below half that of Jupiter and a diameter 1.2 times larger. It is substantially hotter when the temperature exceeds 538 degrees Celsius.
According to NASA, WASP-96 b circles its Sun-like star at one-ninth the distance between Mercury as well as the Sun, completing one cycle every three and a half Earth days.
WASP-96 b is a great target for atmospheric investigations due to its massive size, short orbital period, puffy atmosphere, & absence of polluting light from surrounding objects in the sky.
While the Hubble Space Telescope has studied numerous exoplanet atmospheres over the last couple of decades, catching a first clear detection of water in 2013, Webb’s instant and more detailed observation represents a significant step forward in the search to characterise potentially habitable planets much further than Earth.
Webb’s Near-Infrared Imager and Slitless Spectrograph (NIRISS) monitored light from the WASP-96 system for 6.4 hours on June 21 as the planet passed across the star.
This produced a light curve depicting the overall lowering of starlight throughout the transit, as well as a transmission spectrum displaying the brightness shift of various wavelengths of infrared radiation ranging from 0.6 to 2.8 microns.
The light curve corroborated the existence, size, and orbit of the planet, which had already been determined by earlier measurements.
The transmission spectrum revealed previously unknown characteristics about the atmosphere, such as the unmistakable trace of water, haze, and evidence of clouds that were previously considered not to exist based on earlier observations.
A transmission spectrum is created by comparing starlight transmitted through the atmosphere of a planet as it passes across the star to unfiltered starlight observed while the planet is alongside the star.
Based on the absorption pattern – the positions & heights of peaks on the graph – researchers may discover and analyse the abundances of important gases in a planet’s atmosphere.
Similarly to how persons have unique fingerprints & DNA sequences, atoms and molecules have different patterns of wavelengths that they absorb.
WASP-96 b’s spectrum is not only the most detailed close transmission spectrum of such an exoplanet atmosphere ever captured, but it also covers a remarkably wide different wavelengths, including visible red light as well as a portion of the spectral range not previously accessible from other telescopes, according to NASA.
This region of the spectrum is very sensitive to water, as well as other important chemicals such as oxygen, methane, & carbon dioxide.
Researchers will be able to utilise the spectrum to determine the temperature of the atmosphere with depth, measure the amount of moisture in the atmosphere, constrain the abundance of specific elements such as carbon and oxygen, and measure the amount of moisture in the atmosphere.
They may then utilise this knowledge to draw conclusions about the planet’s general composition, as well as how, where, and where it originated.