webspotting 5 - Fourmilab

As published in the Aug/Sep 2008 issue of SCOPE, the newsletter of the RASC Toronto Centre. Republished here with permission.

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I continuously explore ways I may use "push" technology to monitor, while sitting at my desk, what's going on  in the sky. I can fire up my old Red Shift, or Stellarium, perhaps kStars, depending on the computer nearby. Ensure the date, time, and location are correct. Then pan around the virtual sky, but it's too involved, too many steps and takes too many seconds. There are only 86,400 seconds per day!  And, lastly, it's "pull" technology.

I have considered writing a custom application for my palmtop to list current overhead objects, meteor showers, etc. But that's a serious undertaking.

There are many web sites that can provide this information in some form or another. Recently I told you about skymaps, which offers us a PDF or paper solution.

A couple of months ago I repurposed the Java component at Astronomy magazine's site (http://astronomy.com/) on my web portal page. It notes the planets visible, whether they're in the morning or evening sky. It also sports a marquee.

Searching for something else, I stumbled into John Walker's web (http://fourmilab.ch/). You may recognise his name, particularly if you use AutoCAD, the rather popular computer-automated design software.

Among other very interesting items, I was happy to discover his free astronomy-themed screen saver for Windows. I quickly downloaded it. So, while this is not strictly about a web site, it is a great little utility. When the Sky Screen Saver kicks in, after the designated time delay and the screen blanks, of course, a large circle is displayed. This represents the celestial sphere overhead. North is up; east is west!

The border of the circle changes colour: it is bright blue during the day, dark grey at night, and red during sunset or sunrise.

Constellations are shown. Then, according to your preferences, the planets are shown. Yes, including poor little Pluto. This program is remarkably handy if you're trying to spot elusive Mercury. You may show deep sky objects.

To show more or less stars and DSOs, you adjust the magnitude settings.

When the Moon is displayed, it is shown with a phase. Very handy, whether you like or dislike the Moon.

To prevent burn-in, the electronic planisphere periodically shifts the image.

I enjoy this easy-to-use program. I can glance at my computer, while it stands by, and know instantly what's overhead. I wish I could find a similarly simple yet informative application for my Mac and Linux computers.

Spin off benefit: it is helping me learn the constellations!