My Top 10 Free Earth Science and Astronomy Downloads

I’ve always been what most people call a science junkie and, thanks to the Internet, I’ve learned that there are quite a few more like me.

Free astronomy software has been available online practically since the first personal computers were assembled. But, thanks to the ever increasing processing speeds of both the PC and graphics cards, these programs now have capabilities that were unheard of 3 to 5 years ago.

All of the following programs are freely available over the Internet. Some of these are provided by various government agencies and others are the work of individuals or small volunteer teams. The order in which these programs are listed is purely arbitrary and in no way implies that one is superior to another. I’ve installed and used each of these programs over the last several years and can honestly say that, in my opinion, these are the cream of the crop.

A term you will encounter on several of these web sites is “open source.” Open source means that no one “owns” the software and that its maintenance and future development is open to anyone that wants to contribute to the effort! In fact, you can even contribute by sending the development team a description of any problems that may pop up.

Regardless of their sources and in the order listed, each of these packages has at least 1 thing in common: they’re a lot of fun to play with! But be sure that your computer can handle the high resolution graphics that many of these programs produce.

Let’s begin by looking at 2 of the most popular free “planetary exploration” simulation programs: CelestiaâÂ?¢ and Orbiter.

Program Name: Celestia�
Home Page: http://www.shatters.net/celestia/

Description: CelestiaâÂ?¢ is quite possibly the most versatile astronomy and planetarium simulation software package available on the Internet. The basic program is relatively small (~12 Mb) and comes with several inclusions that take you on a “guided tour” of the solar system (including the planets and their moons) as well as the nearby stars. But what makes CelestiaâÂ?¢ stand out from other astronomy programs is that it can be expanded by downloading “add on” files that contain things like higher resolution planet surfaces, comets, asteroids, star maps, and just about anything else that you could want.

Another feature that separates Celestia� from other programs is that you can download a set of completely self-contained educational programs that cover topics such as the solar system, the search for extraterrestrial intelligence (SETI) or the life cycles of stars.

Program Name: Orbiter
Home Page: http://orbit.medphys.ucl.ac.uk/orbit.html

Description: Orbiter is another program that is maintained by a group of volunteers who actually enjoy answering questions from new users all the way up to experienced pilots. Now in its 3rd major update (I think) this is the most realistic spaceflight simulator I’ve ever encountered.

Orbiter was actually designed to demonstrate some pretty advanced principles of spaceflight such as orbital mechanics, interplanetary navigation, and related matters. Fortunately, the designers have provided one of the more complete sets of documentation that explains it all in terms that the average high school student can understand and then apply along with links to references for those wishing to broaden their understanding of specific areas.

The graphics are a step above most of the commercially available flight simulation programs and provide such a high degree of realism that I again will refer you to the Orbiter screenshots and gallery pages.

While watching a computer simulation of the universe is lots of fun, most of us like to step outside with our telescopes, binoculars or even the unaided eye to see what’s going on in “real time.” The next 3 programs will make it a lot easier to determine where to look and what to look for.

Program Name: Stellarium
Home Page: http://www.stellaruim.org

Description: When I was first getting hooked on amateur astronomy many years ago my biggest complaint was that the sky didn’t look like the star charts. No matter what I tried, I could never get the charts lined up with the stars and the stars would never look like the charts.

Thanks to one of the coolest star chart software I’ve ever see, Stellarium, that isn’t a problem any more. Stellarium takes your local position, calculates local sunset/sunrise as well as moonrise/moonset and then displays what you would see at anytime of the night (including evening and morning twilight)! For example, it will take both the position and stage of the Moon and then display only the stars or other objects that will be bright enough to see in the moonlight (check out the Stellarium Screenshots Page)! For even more fun load Stellarium onto your laptop and take it with you when you go outside, turn the screen brightness down to a minimum, and see what you have probably been missing

As you might have guessed, I can’t say enough in praise of this program

Program Name: Orbitron
Home Page: http://www.stoff.pl/

Description: Orbitron is one of, if not the, easiest artificial satellite tracking software to download (~2Mb) and to use that I’ve found in the last several years. It contains data (sometimes including pictures) of practically every spacecraft now in Earth orbit and can be updated as new satellites enter service.

Another interesting fact about this program is that it was conceived, and is currently being maintained by, Sebastian Stoff of Torun, Poland, and a few volunteers. If you like his program and use it regularly Sebastian asks that you send him a postcard relating to your home town.

Program Name: J-Track
Home Page: http://science.nasa.gov/Realtime/JTrack/

Description: J-Track was one of the very first Java applets produced by NASA dedicated to tracking well-known artificial satellites such as the Hubble Space Telescope, Space Shuttle missions and major “outside the visual range” observational satellites such as Chandra. J-Track is an applet, which means that it runs inside a web page while responding to inputs from the user. There is a version that can “live” on your Active Desktop that performs exactly as the web-based version.

Unfortunately, NASA no longer appears to be actively updating this application (according to the web site, it hasn’t been modified since January, 2000 and it still contains references to the MIR space station). On the other hand, if it’s still running it must be one very stable program. Either way, it’s a fast and simple way to keep track of the more well-known objects in near-Earth orbit.

Some people like to restrict their observations to the Earth itself. Unfortunately, world travel is both expensive and sometimes dangerous. Use the next 2 programs to “see the world” from the comfort and safety of your home.

Program Name: Google Earth�
Home Page: http://earth.google.com/

Description: Google EarthâÂ?¢ is, as you might have guessed, a creation of Internet search engine giant Google. According to the project’s home page, Google EarthâÂ?¢ “…combines satellite imagery, maps and the power of Google Search to put the world’s geographic information at your fingertips.” That may sound like wishful thinking on someone’s business plan but Google EarthâÂ?¢ actually delivers what it promises.

Since I live in Albuquerque I entered my zip code and, after a few moves and clicks, was easily able to count the number of baggage carts parked next to a Boeing 737 as well the number of Air National Guard F-16s parked at adjacent Kirtland Air Force Base.

This program, like the others that offer high resolution graphics, needs both disk space and a fast graphics card; but once you have it installed and running this baby is pure mind-boggling.

Program Name: NASA World Wind
Home Page: http://worldwind.arc.nasa.gov/

Description: World Wind is an ongoing (constantly being revised) project of our friends at NASA’s Ames Research Center. This package is among the largest downloads in size (~60-65 Mb) but I promise you its worth the wait and the disk space. World Wind is similar in concept to Google EarthâÂ?¢ but it contains much more data regarding practically every point on the planet’s surface.

I’m not going to waste your time with my attempts to describe this amazing package. If you want to see a few examples, check out the World Wind Screenshots Page.

The last 3 programs to be considered are for those of us who have a desire to make at least some small contribution to science.

Program Name: SOHO
Home Page: http://ares.nrl.navy.mil/sungrazer/

Description: Like J-Track, this program runs inside your web browser. Unlike J-Track, this site is constantly updated. Launched in December, 1995 as a joint effort of the European Space Agency (ESA) and NASA, SOHO is the acronym for something known as the Solar and Heliospheric Observatory. This satellite does not orbit the Earth or the Sun but instead is “parked” about 1 million miles from Earth at the point where the Earth’s and the Sun’s gravity are equal (the Lagrange point). This allows SOHO to monitor the Sun’s activity in a more or less uninterrupted manner. (This isn’t exactly true but it will make more sense once you visit the SOHO Mission Facts pages).

Although envisioned as a solar research mission, SOHO has also detected special classes of comets called “sungrazers” or, more properly “Kreutz sungrazers.” And this is where the fun starts: using online software and your PC you can search for new comets!

All you have to do is log onto the SOHO Comet Hunting pages; spend an hour or so familiarizing yourself with the basic information, and you’re ready to join the worldwide network of comet hunters.

Program Name: SETI @home
Home Page: http://setiathome.ssl.berkeley.edu/

Description: The SETI@home (Search for Extraterrestrial Intelligence) project has been around since 1999 and is based on a concept called distributed computing. Distributed computing simply means that a network of home computer users have volunteered to host software that will take a small portion of a much larger data set and subject that data to an extensive mathematical analysis before returning the results to the “home” organization and picking up a new data set to analyze. Since its introduction, SETI@home has performed some 2 million years of data analysis (and the Guinness Book of World Records has declared SETI@home to be the largest computer/computer system in the world!

To join “the search for ET” all you need do is log onto the SETI home page, read the appropriate documentation, download the software and wait for the fun to start. As an added bonus, you even get the satisfaction that you’re actually doing something of value to the science community.

Although the following program is not exclusively astronomy-related, it does form the “guts” of SETI@home and numerous other distributed computing projects. Hopefully, I’ll expand on the concept of distributed computing in the future and provide more details on projects that you might wish to join.

Program Name: BOINC
Home Page: http://boinc.berkeley.edu/

Description: BOINC (Berkeley Open Infrastructure for Network Computing) is one of the best overall programs available that allows the home computer user to directly participate in valuable research projects by “volunteering” their computer’s “surplus processing time (an engineering term that means ‘when your computer is on but not doing anything other than just sitting there’)” to analyze small blocks of a very large data set or problems in the sciences.

To become involved in this worthwhile activity, log on to the project’s home page at UC Berkeley, read the information provided (including the FAQs), then download the software itself. Yes, it’s just that simple!

How many other programs let you become a contributor to cutting edge scientific research?