Northern Illinois University
Department of Physics
College of Liberal Arts and Sciences

The objective of this project is to observe as many planets of the solar system as possible and note their location and, if possible, their motion. You will more than likely not be able to observe them all. In fact, a collection of two or three is fine, though it is recommended that you try for others. For some references on the observation of each of the planets individually, look to the other project entries. While more planets are required to be spotted, your actual work with each of the planets will be less intensive than if it was your primary project.

Here is a brief synopsis of the visibility of the various planets of our solar system:

• Mercury will be a difficult prize. It is always trailing the sun closely and so you need to time it so it is in the "dark" sky and at maximal angular sepration from the Sun.
• Venus is probably the easiest find. She follows the sun up and down the the horizon, so it is visible either in the early evening or the early morning.
• Earth; well, lets just say that if you can't observe the earth, you may wish to take some time off, relax and find your brain. However, It is worthwhile to mention the Earth as a member of the solar system.
• Mars appears as a bright red star in the sky. Using a telescope, it resolves into an off-orange disk.
• Jupiter is very nice through a telescope (and easy). During the fall semester, it is a staple of this project. An important aspect is the observation of the moons; evidence that there is motion about other bodies than the sun.
• Saturn is also a nice object to find with the telescope. The rings are usually quite visible. Usually a moon will be visible.
• Uranus is dim and appears more like a blue star from Earth than a planet. Expect long hours in the Observatory trying to figure out which one is which. The blue-green color is the only distinguishing factor that sets it apart from the stars around it.
• Neptune is like Uranus, only worse. One should receive double credit toward the quota of three planets if Neptune is found and verified.
• Pluto is not an object you will be able to see with the school's telescopes. The planet is far too dim for even the best Earth-based telescopes to detect reliably. Photos of Pluto taken with Hubble or at the Palomar Observatoryare readily available.

Procedure

1. Locate each planet in one of the four main telescopes at Davis Hall. The reflector or the 4" and 6" refractors are recommended. Different telescopes will be better for different objects.
2. With the observatory manager's assistance, capture at least one image, or more if you choose. Try several different images in different scopes and powers of magnification. Try to complete as many different images as possible. Even better, take images with a time sepration of at least a month for close mobjects like Venus or Mars.
3. The pictures may be enlarged so that details may be more visible.

Data Interpretation

Look at what stars are near the solar system object and so which constallation it is in. If you take data at different times, note the "motion" of the planet relative to the stars.Reference some of the other planetary projects to see what sort of data can be collected and interpreted. Keep in mind that this is a general survey, and one should not have to analyze and pictures too closely.