The James Webb Space Telescope (JWST) observed two clouds on Titan on November 4, aiding researchers in exploring Saturn’s moon.
Titan moon captured by JWST’s NIRCam. (Photo: NASA)
Titan is a peculiar celestial body resembling Earth, composed of water ice, rivers, and seas filled with methane and other hydrocarbons, along with a thick atmosphere rich in fog and sparse methane clouds. Conor Nixon, an astronomer at NASA’s Goddard Space Flight Center in Maryland, arranged for the JWST to spend a total of 15 hours observing Titan in its first year. Notably, Nixon and his team aim to study Titan’s atmosphere to map fog distribution and identify new gas types. Scientists were quite surprised by the data transmitted from the JWST.
Upon examining the data, the research team identified two clouds, including one located above Kraken Mare, Titan’s largest sea. They quickly devised a method to monitor the clouds to understand how they change over time. Nixon’s team reached out to the Keck Observatory in Hawai’i, which conducted observations of Titan just two days after the JWST.
“We were worried the clouds would be gone by the time we observed Titan two days later with Keck,” shared Imke de Pater, an astronomer at the University of California, Berkeley. “But we were delighted to find the clouds still in the same position, although they seemed to have changed shape.”
Scientists predict increased cloud activity as Titan’s northern hemisphere is experiencing summer and receiving more solar radiation. They identified the clouds in images taken by the Near Infrared Camera (NIRCam) of the JWST, a powerful camera capable of capturing targets at various wavelengths of light. In the case of Titan, this allowed the research team to differentiate the lower atmospheric regions.
The researchers have not yet completed their assessment of all NIRCam data. The Near Infrared Spectrograph (NIRSpec) of the JWST is also collecting data. For example, the instrument can separate the light reflected from Titan’s atmosphere and measure the amount of each wavelength of light. The JWST is also scheduled to observe Titan’s fog layer in May or June 2023, this time using the Mid-Infrared Instrument (MIRI), which will enhance understanding of the chemical composition in Titan’s atmosphere.
Observing Titan is particularly important. NASA’s Cassini mission arrived at Saturn in 2004 and flew by this moon over 100 times before concluding in 2017. NASA is developing a new mission named Dragonfly, in which a drone will fly through Titan’s foggy skies.
