It is ten times farther from the Sun than Earth, has a thick atmosphere, its surface is varied in topography and is dotted with lakes, seas and even rivers – this is Titan. On the surface of the moon, however, hydrocarbons (methane, ethane) form lakes, and these compounds also create a dense haze in the atmosphere that hinders visual observation.
At one time, NASA’s Cassini spacecraft, which investigates the Saturn family, and Huygens, a separate small European-made and operated probe that traveled with it, visited the moon and successfully landed on the surface of Titan in January 2005 However, Cassini’s mission ended in 2017 and there is still a long way to go until the next mission that will investigate this region of our Solar System. That’s why it’s extremely important Capacity of the James Webb Space Telescope make ultra-modern remote observations thanks to its excellent technical capabilities.
The recordings were made two days apart. On the left side of the image is the James Webb image, on the right side is the next image of the Keck Giant Telescope on Earth. Both were taken in the near infrared, and while they don’t “see” the same way, it was possible to detect the change in weather by comparing these two images.
Source: NASA, ESA, CSA, WM Keck Observatory, A. Pagan (STScI
On December 1, 2022, the images taken by the space telescope a month earlier, on November 4 and 6, were made public, and in which we can also observe the changes in Titan’s cloud cover. Webb and operating in Hawaii Keck giant telescope as a result of their joint work and thanks to the observation of the infrared wavelength, we can enjoy a sight that specialists have been waiting for many, many years. Webb can not only look at the composition of the moon’s atmosphere, but also detect its time and even get some images of the surface, in the form of its dark and light regions. Titan is the only moon in the Solar System with an atmosphere, which makes observations of it particularly interesting.
A comparison of near-infrared NIRCam images taken on Nov. 4 showed that a cloud can be seen in the northern hemisphere of the moon — not long after, another cloud was also successfully observed. And these were important because they confirmed previous computer models of Titan’s climate.
Keck ad illustration with diagrams of the two tools. The blue arrows point to the two clouds.
Credit: NASA/STScI/Keck Observatory/Judy Schmidt
After it became clear they had found the clouds, the Keck telescope operators were asked to follow up very quickly and were able to classify the observation two days later. This confirmed: there were indeed clouds in Webb’s images, and the new observation also highlighted their changes. While it can’t be said with certainty that the two telescopes saw the same clouds, or that new ones formed in similar locations in two days (seasonal lighting still makes that possible), it is certain that we are seeing the weather seasonal. As soon as Keck’s recording was completed, the next step was the work of a specialist involved in modeling Titan’s atmosphere, as what was seen had to be interpreted.
The fact that Webb’s near-infrared spectrograph also made observations was a further aid in interpreting the recordings – with the help of this, we can also see components of the atmosphere and the moon that would otherwise be impossible with observation terrestrial due to the obstacle posed by our atmosphere. The analysis of these data is still ongoing, but if it is completed, we will know more about the lower layer of Titan’s atmosphere and the chemical composition of the surface. In addition to the subsequent repetition of the current ones, in the summer of 2023, Webb’s other instrument called MIRI will also make observations at wavelengths never seen before. This data may help reveal why Titan may have an atmosphere.
