Saturn

Considered by many the most beautiful planet in the Solar System, with its breath-taking colours and spectacular ring system, Saturn is arguably the most iconic of all planets. The features of this Gas Giant are so unique that a simple glance at this beautiful world through a telescope is likely to turn an unwary observer into an astronomer forever!

Although the first observation through a telescope was only done in 1610 by Galileo, Saturn is known to humanity since ancient times. The Romans named it after their god of agriculture and harvest before they went on to name a day of the week after it, no later than the 2nd century (Saturday from “Saturni dies” or “Saturn’s Day”).

Over 95 times more massive than Earth, and with an average radius of about nine times that of our home planet, Saturn is the second largest planet in our solar system, after Jupiter. At a distance of 1.4 billion km, it is the sixth planet from the Sun and the farthest planet from Earth to be visible to the naked eye with its steady yellow glow.

What is not visible to the naked eye, however, is Saturn’s most distinctive and spectacular feature: its prominent structure of seven rings separated by gaps and divisions, with the Cassini division as the largest and most obvious. The rings are largely made of tiny chunks of ice along with rocky debris and dust, which according to NASA are pieces of comets, asteroids or shattered moons that were torn apart by Saturn’s powerful gravity.

The body of Saturn, on the other hand, is a Gas Giant much like Jupiter, made of hydrogen and helium with a presence of ammonia crystals in its upper atmosphere that confer the planet that distinctive pale-yellow hue among shades of brown and grey.

In line with its fast-rotating magnetic field, the ringed planet spins on its axis fast enough to claim the second-shortest day in the solar system (slightly below 11 hours) while a complete orbit around the Sun (a Saturnian year) lasts about 29.4 Earth years. Moreover, the tilt of its axis, somewhat similar to that of our planet, suggests that Saturn too experiences seasons.

Credit: NASA ®

Another interesting characteristic that once again emphasises the gigantic size of Saturn, is the incredible number of moons that orbit the ringed planet. At the time of this article, in fact, Saturn boasts 82 known moons, of which the biggest, Titan, is the second largest in the Solar System, bigger than the planet Mercury!

But it is not just the size that makes Titan interesting; this rocky world is the only moon in the Solar System known to have a dense atmosphere and the only place besides Earth known to have liquids in the form of rivers, lakes and seas on its surface. While these waters are mainly made of liquid hydrocarbons like methane and ethane, liquid water more similar to what we are accustomed to is present beneath Titan’s thick crust of water ice. It is this abundance of liquids that makes Titan a serious candidate in our search for extra-terrestrial life in the Solar System!