Discovering Comets with Your Personal Computer

In my previous article I introduced readers to the web-based scientific research being conducted by volunteers at the Zooniverse Project . In that posting, I promised to show you a very cool application that has grown out of the technology used to study our sun. Being a man of my word, I will use this post to keep my promise. In today's article I'll show you how, in four relatively simple steps, to use your personal computer to search for previously undiscovered comets.

1. A Little Background Information

The majority of comets that you may potentially identify belong to the "type" or "family" of comets known as the Kreutz Group or Kreutz Sungrazers (after German astronomer Heinrich Kreutz, and the fact that these comets usually travel much closer to the sun's surface than other comets). Although most of these comets are quite small, some members of this group have produced spectacular displays (See the links in the box below). You will be using two sophisticated satellites to look for comets: SOHO and STEREO.

Of the approximately 2,000 Sungrazers discovered thus far, 99% were detected by the Solar and Heliospheric Observatory (SOHO ) satellite, a collaborative project of the National Aeronautics and Space Administration (NASA ) and the European Space Agency (ESA ) was launched in December, 1995. SOHO is "parked" at the point in space known as the First Lagrange Point (L1) , where the gravitational influence of the Earth and sun are roughly equal. At this location, the sun is always within SOHO's field of view.

The Solar TErrestrial RElations Observatory (STEREO ) mission began in October, 2006 and involves two identical spacecraft that are orbiting the sun in two different positions. Since these satellites are viewing the same object from different positions, the STEREO mission allows Earth-based scientists to create 3-dimensional images of processes on and near the sun. Although STEREO data usually isn't as useful as SOHO, it sometimes serves to confirm the location of activity near the sun.

2. Visit the "official" web site and read the "'Official Guide' to SOHO Comet Hunting"

If you're one of those that "read the manual as a last resort" (like me), this is as good a time as any to break yourself of that bad habit. Trust me, you will save yourself (and the SOHO team) a lot of grief if you read the manual BEFORE you try to find a new comet!

You should also read and reread Sebastian Konig's "Guide to SOHO Comets ." Sebastian has about 40 discoveries to his credit, so you can certainly benefit from his experience and insight.

3. Use the links provided in the "Download some practice images!" section of the Guide to develop your comet-hunting skills

Besides reading the Guide / Manual, your chances of discovering a new comet will improve if you run through the "practice" image files. These files were selected by the SOHO team because they demonstrate both the characteristic appearance of comets AND the more commonly encountered artifacts, or "noise," that might throw you offtrack when searching for comets.

4. Look for some comets!

After you have ran through the practice image sets a few times, you'll be ready to tackle the near-real time images generated by SOHO and stored in an online database. These images can accessed by clicking this link , which takes you to a page called "Select a LASCO / EIT Real-Time Movie." On this page you will be given several options which can be selected by clicking the appropriate "radio button" located next to the various image sizes. I suggest selecting "GIF (512X512)" and "Yes" under the heading "On Screen Controls."

Should you feel that you have discovered a previously undetected comet, go to the page "SOHO LASCO Comet Finders Page ." At the bottom of this page is a JavaScript form where you would report your observations to the appropriate agency (the Naval Research Lab in Washington, DC).

Wrapping up, I have presented yet another way to use your free time and your personal computer to "do some real science." In my next posting we will visit one of the more fascinating locations in the solar system, the planet Mars, for another round of real science using your personal computer.