The Night Sky: The Planet Saturn

Attached are two pictures of Saturn taken about a year apart. One is from April 2011 and one from March 2012. I took both at the Mary Aloysia Hardey Observatory at the .

Saturn is tilted about 27 degrees so we see it from different angles as it progresses through its seasons. Saturn takes over 29 years to revolve once around the Sun, so a season on Saturn is about 7 years long.

Notice the difference in Saturn’s axial tilt during the year that separates the two pictures. In 2011 the rings were seen nearly edge-on as Saturn came out of its spring equinox. In 2012 the angle of the rings has increased as Saturn progresses toward summer in the northern hemisphere in 2017.

Saturn was closest to Earth on April 15^th 2012. At that time it was opposite the Sun in our sky, and is said to be at ‘opposition’. For several months near opposition Saturn is well placed for viewing in a telescope.

Saturn is a ‘gas giant’ made of 75% hydrogen and 24% helium, plus a small rock core. By volume Saturn is 760 times larger than the Earth, but is unique among the planets by having an average density less than water. For such a large planet it rotates fast. A day on Saturn is only 10 hours and 34 minutes. This rotation action whips the gas giant into light and dark bands. 

Saturn has 53 named moons, but the real attraction to Saturn is its rings. The rings are countless water ice particles orbiting around Saturn. They are very bright because ice reflects sunlight very well. Speaking of sunlight, it takes sunlight reflected off of Saturn’s rings about 71 minutes to travel the 1.5 billion kilometers to reach Earth. Although spectacularly large, the rings are very thin. It is thought that if you put all the ring material into a ball, it would only be about half the size of Connecticut.

Saturn is the farthest planet you can see without optical aid, and can be found in the constellation Virgo, but it goes without saying that the true beauty of this planet is realized when viewed with a telescope. If you have not seen Saturn in a telescope, you should, it truly is a stunning planet.

Starry Nights!

Image Technical Details:

Processed in Registax and PhotoshopCS5

Canon T2ia Camera

EOS Movie Record software

Meade 16”LX200 telescope

Mary Aloysia Hardey Observatory