Our solar system contains a wide variety of planetary bodies, from the inner, small rocky planets to the outer solar system’s massive gas giants. While the most massive of the gas giants, Jupiter, is indeed a sight to behold in its own right, Saturn is undisputedly the more well-known planet, due to its pronounced ring system.

Indeed, all gas giants in our solar system have a ring system associated with them. However, for Jupiter, Uranus and Neptune, this ring system is extremely faint, almost unobservable from Earth. Saturn’s ring system, on the other hand, spans a distance approximately equivalent to the distance between the Earth and the Moon. Even covering such a massive span, however, Saturn’s rings are only around 10m thick on average! The reason why their appearance is still so pronounced from Earth, over a billion kilometres away, is due to their nature and composition. Indeed, Saturn’s rings are composed of pieces of rocks and ice, the latter being extremely reflective to sunlight.

Saturn itself, apart from its ring system, is a massive gas giant, falling short of Jupiter’s massive diameter by around 35,000km. At a diameter of around 116,000km, however, it still dwarfs our planet, Earth, which stands at a diameter of around 12,900km. Being a gas giant, Saturn has no solid surface and what we observe through our telescopes is indeed just the upper layer of its massive atmosphere, which makes up the planet itself.

Just like Jupiter, Saturn is mainly composed of hydrogen and helium, with some methane and other trace components also present. As opposed to Jupiter, however, Saturn’s surface appearance is largely featureless, except for a persistent massive hexagonal cloud pattern over its Northern polar region. The same featureless surface appearance, at least in visible-light observations. is also observed for Uranus and Neptune, and the lack of storm features, as opposed to those observed on Jupiter, is thought to be due to the other three gas giants receiving less solar irradiation, and consequently being colder, than Jupiter.

Saturn’s ring system and its formation remain a subject of debate to this day. One theory is that the rings were formed when a moon of Saturn got too close to the planet, resulting in it breaking apart due to gravitational interactions with the planet. The resultant material fell in orbit around Saturn, forming the ring system. The rings, however, are thought to be in a degrading orbit, and will one day fall into Saturn themselves as they slowly get closer to Saturn.

Dr Josef Borg completed a PhD in Astronomy at the Institute of Space Sciences and Astronomy, University of Malta, and is currently a researcher at the Faculty of Health Sciences at the University of Malta.

Sound Bites

 •        Scientists with an improved explanation for the most energetic explosions observed

          Gamma-ray bursts, which are observed to originate from extremely faraway galaxies, are now thought to mostly originate from star-forming regions in such galaxies. The so-called empty sly gamma-ray bursts could indeed be explained by galaxies with higher rates of star formation, which would also lead to higher rates of supernovae, perhaps causing the observed bursts.

•        Ingenuity prepares for its 14th hop on Mars

          The Ingenuity helicopter, which has already performed 13 manoeuvres on the red planet, will be doing a five-metre climb using faster rotor speeds than it has used thus far, before making a sideways manoeuvre and landing again on the Martian surface. Due to seasonal variations on Mars, the atmospheric density is getting thinner, resulting in the requirement for higher rotor speeds to be used to drive Ingenuity.

For more soundbites listen to Radio Mocha every Saturday at 7.30pm on Radju Malta and the following Monday at 9pm on Radju Malta 2. Follow on Facebook.

DID YOU KNOW?

 •        Sometimes, Jovian-like storms appear on the other gas giants too! Although rarer and more fleeting in nature, storms do sometimes appear on the other gas giants apart from Jupiter. An example is the seasonal Great White Storm on Saturn.

•        Earth is not the only planet with aurorae! Indeed, with significantly stronger magnetic moments than Earth, the gas giants all experience aurorae, which have all been imaged. The Northern (and Southern) lights are therefore not a unique feature for Earth!

•        Landing on Saturn’s moon Titan!  The landing of the Huygens probe on Titan’s surface in 2005 marked the farthest ever landing of an unmanned probe, snapping images of its descent and recording altitudinal atmospheric data for Saturn’s largest moon.

For more trivia, see: www.um.edu.mt/think