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Saturn & Jupiter

Saturn reached 'opposition' (closest it'll be to Earth all year) on Aug 2nd and Jupiter reached opposition Aug 19th meaning now's the best time to see both of them!

Saturn is currently appearing in the southeast next to Jupiter (the brightest 'star' in the southeastern sky after sunset) in our evening sky. Saturn is much dimmer than Jupiter but it is much brighter than the stars that surround it. Saturn makes almost a straight line in the sky with Jupiter currently at sunset.

Location of Jupiter and Saturn

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 on 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 into 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.

Saturn, like the Earth, has solstices and equinoxes. Saturn takes 30 years to go around the Sun meaning 30 Earth years = 1 Saturn year. 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 is currently going into equinox, meaning 2021 will be the best time to view the rings till 2028 when they start to open up again

The brightest ‘star’ appearing in the southeast is actually the planet Jupiter. Jupiter is the largest planet in our solar system at 11.6 times the size of Earth in diameter (86,881 miles), making it 1,322 times the size of Earth in volume. You could fit over a thousand Earths inside Jupiter. Being so massive has made Jupiter a solar system within our solar system, as its extreme gravitational pull captures lots of objects as moons of Jupiter.

Jupiter and 4 moons as seen in a pair of binoculars.

If you look at Jupiter with a decent pair of binoculars you will be able to see 4 of Jupiter's moons: Io, Europa, Ganymede, and Callisto. These are called the Galilean Moons as they were first observed by Galileo in his small telescope. They are very easy to make out even in small telescopes/binoculars. Telling which one is which takes several observations over a longer period of time as they are circling Jupiter and you can only see this movement edge on from Earth. To determine a moon’s true distance from Jupiter you must watch the moons to see when they stop getting further from Jupiter, turn around and get closer.

All of the Galilean Moons are interesting places and studied extensively. Io (the closest) is the most volcanic body in our solar system. Europa is the smoothest body in our solar system; it’s believed to have liquid water and therefore possibly life beneath it’s Ice surface. Ganymede is bigger than the planet Mercury, and Callisto (the furthest out) is the most cratered body in our solar system. With a good pair of binoculars you can also see red stripes contrasted with white stripes; this is Jupiter’s atmosphere. The change in coloration is caused by different compounds in the atmosphere that change color when exposed to the light of the Sun.

With a really good set of binoculars or a decent telescope you can see the red spot which is an acid hurricane more than twice the size of Earth that has been observed since at least 350 years ago. A day on Jupiter lasts about 10 hrs, so over the course of a long winter night you can watch Jupiter do a full rotation by watching the great red spot do a lap around the planet.

If you want an up close view of these planets and more please join me on one of my astronomy programs.

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