Celestia

[fragger]

If anyone's interested, I've discovered a fantastic piece of astronomy software called Celestia. What's revolutionary about it is that instead of just allowing you to view the night sky from a location on the Earth's surface, you can view the universe from anywhere in space, from any angle. You start from a point above Earth's surface, which you can drag yourself around, Google Earth-fashion (it's not Google Earth, though - you won't find your home street on it or anything ;D). To go somewhere else, either enter an object name (say for instance, Jupiter or Alpha Centauri) or click on any visible star or object in the field of view, hit "g" or right-click/GoTo, and whoosh - you'll whiz smoothly through space to that object in true warp-speed style. Graphics are tremendous - instead of just using dots, symbols or static images to represent, say, planets in our Solar System, zooming to them will reveal beautifully rendered, fully 3D-viewable, interactive real-time models of them that can be orbited around, zoomed in on, etc. It's a remarkable and flexible program that's being used by NASA, universities and schools, and is rapidly growing in popularity among astronomers, both professionals and amateurs.

And here's the best part - it's absolutely free! You can download the base program from:

http://www.shatters.net/celestia/

That's just the basic program, and even though it has quite a few options, much, much more can be added on to it. At present, there are about 8Gb worth of add-ons available for it, and it's growing all the time. A list of popular add-ons can be viewed from the Home Page/Add-Ons tab (then click on the hyperlink, "Celestia Motherload"). The add-ons are many and varied, such as extra graphics files for objects, animations, spacecraft tracking, larger object databases - there's heaps. Some are even fanciful - for instance, you can add-on the Star Trek, Star Wars or Babylon5 universes, among other fictional options.

If you're into astronomy at all, or even if you just want to cruise around in space, I highly recommend this, especially once you get a few good add-ons going. If you consider obtaining Celestia, it's very much worth downloading the User's Guide first, just to get an idea of what it's all about and whether you think it'd be for you (go to "Documentation" from the home page - there's a choice of either Word or Acrobat versions of the User Guide). This is a very informative 48-page guide that gives you a thorough rundown on all the ins and outs, with good helpful screenshots. It also contains a list of additional add-on sites.

Celestia is a refreshing approach to astronomy, and is the most fun I've had with a bit of astronomy software in years! I've always hoped that someone, sometime, somewhere, would make something like this :-X

[JRD]

Thanks fragger... it really sounds cool!

I remember using a sextant and a sky map when I did a 22 days internship on a navy vessel long ago and I was astonished by astronomy!

It was one of my favorite subjects when I was young, I actually thought I`d be studying astronomy at the oceanography school but it turned out to be meteorology instead (  ::) )

I also remember a TV show called "Cosmos, with Carl Sagan" every saturday morning... I used to like that better than some cartoons!!!  ;D ;D

[Art Blade]

Thanks fragger, I remember that software :) I used to play with it many moons ago, and there was another program which was kind of similar (can't recall its name though). I remember that I downloaded hi-res surface images for planets and such, and how I admired those orbiting something like Mars etc. Good pastime  :-X

[PZ]

Great find fragger - thanks for posting!  :-X

[fragger]

You're very welcome :)

I should point out that Celestia is not what you'd call an astronomy "tool", more a fun way of looking at the universe. You can, for instance, centre your view on a planet such as Jupiter, speed up time and watch the planet rotate as its moons orbit around it, or select a moon and watch it sail past its planet, all beautifully rendered (in the "Help" menu is a very useful rundown of keyboard commands, also in the comprehensive User's Guide). It also lets you see just how arbitrary "constellations" actually are, by selecting a star in a given constellation and rotating your view around it (the Pleiades star cluster is great for trying this). You'll see the other stars shifting their positions accordingly as your view rotates, demonstrating the fact that constellations are actually just line-of-sight coincidences as seen from Earth, i.e. the distances between them along the line of sight are actually far greater than the distances between them appear to be to us. Switch on "Constellation Lines" to really see this effect.

For amateur astronomers, a much more useful, and also free, piece of software is Stellarium, which is of a much more practical and prosaic nature, but which shows the sky from any place on Earth in real time, also beautifully presented and well worth getting if you're into this subject. You can pan your view around, zoom in and out (which is cool when you zoom in on a planet or the Moon) and see the sky not just as it appears now, but for any time past or present (up to, I think, 9,999 years forward or back, if you really want to). You can get it from:

http://www.stellarium.org/

[tehsam016]

Great find fragger. It's amazing that every little star in space has it's own name and sometimes planet system.