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Astr111 Photography Projects, Spring 2007

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Saturn, Joshua Ho


Saturn Moons

First observed with a telescope by Galileo in 1610, Saturn is the 2nd largest planet in the solar system and the sixth planet from the sun. The distance of Saturn from Earth, is about 1,279,800,000 km away. A well known feature of Saturn are its rings, which consist mostly of ice particles with a smaller amount of rocky debris and dust. Physically Saturn's density is so low, it is less than water! Saturn is also known for being a gas giant, with 75% hydrogen and 25% helium. The core of Saturn is made up of a rocky core that can reach up to 12000 K, resulting in it radiating more energy into space than it receives from the Sun. The core is surrounded by a liquid metallic hydrogen layer, and a molecular hydrogen layer.

The first image is a combined color image of red, green, and blue filters. There are two shadows that can been seen. The first shadow can be seen due to Saturn's own shadow on its rings at the bottom left. This shadow is produced by the Sun's position being to the right. The second shadow is the exact opposite, where the rings produce the dark line on Saturn. The rings themselves are made of bits and pieces of ice, where the inward parts of the rings are thick and the outward parts are very transparent. Also, Saturn spins on its axis very quickly which explains the bands across the planet, particularly the one in the middle (yellow). This picture however does not do these bands justice, where a higher resolution photograph would portray seven or eight separate bands.

The second image is overly exposed image of Saturn in order to portray the orbiting moons. Titan is located at the left corner, Dione is just left of Saturn, Rhea is to the bottom right. The object above Rhea is a USNO star. Titan is very unique because not only is it the largest moon of Saturn, it also is the only moon to have its own atmosphere. Rhea is characterized by being very cold and having icy surfaces.

Since Saturn is so bright, the exposure time was calculated to be very short: only 0.2 seconds. The angular size of Saturn is 74 arc seconds and the linear size of Saturn is 6.1x10^8 Meters.


Nine Planets. http://astro.nineplanets.org/twn/n7293x.html

Solar Views. Solarhttp://www.solarviews.com/eng/saturn.htm

TheSky Software


Right Ascension (J2000) 08:31:55
Declination (J2000) +19:38:29
Filters used blue(B), green(V), and red(R)
Exposure time per filter 20 X 0.2 seconds BVR
Date observed

March 17, 2007 (BVR)