As part of a Saturn observation campaign, the James Webb Space Telescope has captured images of the planet using its NIRCam camera, an instrument that is sensitive to near-infrared radiation. With these observations, the telescope has been able to show details of great scientific value of the planet’s atmosphere, as well as its rings.
In infrared light, Saturn appears very dark, since methane gas, very abundant in its atmosphere, absorbs almost all the light coming from the Sun and, therefore, hardly any radiation is emitted into space. Instead, the large presence of water ice particles, together with rock fragments, in the composition of the rings ensures a good reflection of the incident light even in the infrared wavelength. The result is a striking and highly unusual image of the planet.
These observations of Saturn complement those already made by the James Webb telescope of Jupiter, Uranus and Neptune, the other large gas planets in our Solar System.
The images captured by Webb allow us to visualize details of Saturn’s stratosphere, an area that is about 200 km above the planet’s high clouds and that, unlike these, is not accessible to observations with visible light.
Specifically, darker areas are perceived, especially in the northern hemisphere, which do not follow the distribution in the form of bands parallel to the equator that is so typical of the atmospheres of Jupiter and Saturn. Scientists believe that these spots indicate the presence of aerosol formations, tiny particles that absorb incident radiation much more efficiently.
There are other telling details as well: despite the fact that it is currently summer in Saturn’s northern hemisphere, the northern polar region appears especially bleak, which could suggest an accumulation of aerosols in this part of the stratosphere due to some seasonal phenomenon that, at the moment, it is unknown to us.
The brightness that can be seen in the outline of the planet does not go unnoticed either. Scientists believe that these luminescences may be caused by the re-emission of light absorbed by methane molecules overhead (through a fluorescence process), or by radiation generated by triatomic hydrogen ions (a molecule made up of three hydrogen atoms and that it is very abundant in the universe). Detailed studies of the information captured by the Webb will be needed to be able to determine this aspect with greater precision.
Saturn’s ring system is perfectly defined in images captured by the space telescope’s NIRCam camera. Although the rings discovered in the other gaseous planets of the Solar System (Jupiter, Uranus and Neptune) are composed mainly of rocks and dust, those of Saturn contain a high percentage of water ice, in fragments that can be as small as a grain. of sand or as big as one of our mountains.
The data generated by James Webb will also make it possible to study in detail the weak E ring, which occupies a wide region located between 180,000 and 480,000 km away from the planet. This ring is of great scientific interest, since the particles that make it up come from the underground ocean of Enceladus and have been ejected into space by geysers located near the south pole of this Saturnian moon. Enceladus is one of the most promising places in the Solar System for the search for life.
It is not ruled out that the analysis of the observations made by James Webb will reveal new and small moons of Saturn. This planet holds the record for satellites in the Solar System, with a total of 124 discovered so far.
