• Luke

Saturnus

Saturn is a favorite among everyone. The days of the week are named after celestial bodies and Saturn’s day (Saturday) is also beloved by all! You’re probably thinking about it so here are the rest: Sunday = Sun’s Day, Monday = Moon’s day, (knowing Spanish helps with the others, English took some Norse gods like Thursday=Thor's day) Tuesday = martes = Mars Day, Wednesday = miércoles = Mercury’s day, Thursday = jueves = Jupiter’s day, Friday = viernes = Venus day. Seems like Earth day got a raw deal only being one day a year...


Saturn and its rings taken over a period of three hours by the wide-angle camera on the Cassini spacecraft. (NASA)

Saturn is currently appearing in the south next to Jupiter in our evening sky it is much dimmer than Jupiter but it is brighter than the stars that surround it. It makes almost a flat straight line in the sky with Jupiter (the brightest 'star' in the Southern sky after sunset) currently at sunset and will get more angled later in the night and later in the year. This line actually goes across the whole sky surrounding the Earth and is the line of the ecliptic (the only place you find the planets, the sun, and the moon is on this line because it denotes the plane of our solar system. Late at night (currently about 10p) going along this line due east you will see a bright red 'star' rise, Mars!



Diagram showing the Celestial sphere with ecliptic and equinoxes

Saturn is currently visiting the constellation Capricorn which can be seen below it. Saturn is a true treat in binoculars or a telescope. When you first see it you might see an oval resembling a batman symbol but once you focus your eyes in to it you should see Saturn's rings resolve. Saturn never fails to get an “oh wow!” from anyone looking at it up close, the large planet suspended perfectly in the rings is a magical sight to observe with your own eyes. If you really want to test your eyes and equipment you might see ‘the Cassini Division’ which appears as a dark region that separates the bright ring in to 2 rings. The rings are made up of countless water ice particles ranging in size from the smallest speck to the size of a house.

common view of Saturn in a telescope.

Saturn like the Earth has solstices and equinoxes, and you can see them by observing the rings from year to year. Saturn takes 30 years to go around the Sun meaning 30 earth years = 1 Saturn year. every 30 earth years Saturn has 2 solstices (i.e. summer & winter) and 2 equinoxes (i.e. spring, & fall). We see Saturn's solstices by seeing the rings tip towards us and appear to open up and we see Saturn's equinoxes by observing the rings edge on, where it’s difficult to notice the rings at all. Saturn’s last solstice occurred in 2018 this means Saturn was tipped towards the Sun opening it’s rings as wide as can be seen. Over the next 5 or so earth years we will watch Saturn's rings tip away getting smaller and smaller until it reaches equinox where we will see the rings edge on.


How Saturn will look at opposition (when closest to Earth) for the next nine years

When Galileo first saw Saturn's rings he of course didn’t know what he was looking at, some of his first sketches depict it with two moons (he had already discovered the moons of Jupiter making this a reasonable guess). After he caught his first glimpse he got clouded out and wasn’t able to see Saturn again, then once the clouds left Saturn was no longer in the sky (Saturn was too close to the Sun to be observed). Galileo knew about the movements of the planets by now so he waited till he could see it again and when he did the rings were no longer visible (Saturn had gone into equinox where the rings were edge on) this lead Galileo to think he had hallucinated when he first saw the rings. Saturn’s Greek god name is Κρόνος, Krónos who was a Titan that ate his children. Galileo knew this story so when he saw the “moons” next to Saturn disappear he thought just like in the myth Kronos had ate his children. He checked back over the next few years to see them open up again he never truly realized what they really were, later calling them "arms".


After taking in the rings of Saturn if you look around just of next to Saturn somewhere you should see the moon Titan (yes this is where Thanos is from) . Titan is the second largest moon in the solar system (after Jupiter’s moon Ganymede) and slightly larger than even the planet Mercury. Titan is really exciting for planetary researchers as it is rich in geological processes that are alien to anything seen on Earth yet somewhat familiar. I’ll give you an example much like Earth Titan has clouds in its atmosphere and lakes on its surface however Titan’s lakes and clouds are not made of water but made of methane. It is thought that methane on titan acts much like water acts on Earth. Because Titan is so far from the sun it is much colder but these cooler temperatures make it possible to have methane as a solid, liquid, and gas. When heated methane lakes evaporate into clouds that when cooled then rain and/or snow methane back down to the surface.



The Huygens probe that was sent with the Cassini spacecraft landed on the surface of titan in 2005 and proposed missions want to go further some with a submarine to be deployed in a methane lake. Just imagine what a feat of engineering that could be to have a submarine in a methane lake on a moon of one of the most distant planets in our solar system.


My new Bumper stickers are in! come to a tour to pick yours up for free!

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