One writeup from other module (PC1322)

This photograph was captured on 30^th January 2015 during the first star gazing session of Understanding the Universe.

The equipment used to capture the photograph is a combination of my phone’s camera and the telescope borrowed from the stargazing session. The model of the telescope is a VixenR130sf Newtonian telescope from Vixen Optics. It has a light gathering power of 345X and resolving power of 0.89 arc sec. The focal length is 650mm and has a focal ratio of 5.0. The model of the phone camera is iPhone 5s from Apple. It is 8 megapixels and has an f/2.2 aperture.

The setting was at night around 9pm under non-cloudy weather condition, when Jupiter is clearly visible from the skies above NUS.

This is a picture of the planet Jupiter and three of its four Galilean moons. There are a total of 67 confirmed moons of Jupiter but the biggest 4 among them are named the Galilean moons. They are Io, Europa, Ganymede, and Calisto. The instruments that I used, however, are not powerful enough to let me see the features of the moons to determine which moons are Io, Europa, Ganymede, and Calisto. As the moons are orbiting around Jupiter, the fourth moon should be behind Jupiter, out of our line of vision when this photo is captured. I can see the features of Jupiter with my naked eyes through the telescope itself, but Jupiter appears bright in this photo because of the manual exposure settings. Although my iPhone camera has a good resolution, it does not have the manual exposure control settings that is needed to capture planetary features such as the cloud belts and the Great Red Spot. A moon filter is needed is reduce the brightness of Jupiter’s disc for us to observe the planetary features through the smartphone. Also, the moons appear to be the same in size in this photo but they differ very much in size. The largest moon is Ganymede, with a diameter of 5262.4km. The smallest moon is Europa, with a diameter of 3121.6km. This huge difference in diameter is not distinct to us on Earth as we are very far away from Jupiter.