Wednesday, August 8, 2007

Satellite Gazing: An Alternative to Stargazing?

With the Leonid meteor shower slated for November still a few months away, are artificial satellites worthy targets for amateur astronomers in our increasingly light polluted urban night sky?


By: Vanessa Uy


Orbiting satellites of various shapes and functions had recently become “prime targets” for the starter-kit-astronomical-telescope-owning-amateur-astronomer in today’s increasingly light polluted urban night sky. The satellite’s much higher “relative brightness” rating when compared to other “dimmer” heavenly bodies like the planets Mars and Jupiter make these objects shine out above the orange barf glow permeating your local city’s night sky. Short of doing LASIK surgery on my trusty-but-rusty mass-market Celestron reflector, there’s not much you can do to alleviate the effects of “light pollution” especially if you live with your telescope in an urban area. I’ve read that there are certain people –especially in the United States- who genuinely believe that lighting up 10 million- candle- power street lamps has the power to render any modern assault rifle impotent and obsolete. You might be unknowingly voting for them into your local city council, so please talk sense into them on your spare time. Or send them to downtown Baghdad to test out their policies.

Ever since the launch of Sputnik back in 1957, the number of “space birds” that orbit our planet has been growing steadily. From those that were prime observing targets during their operational lifetimes like SKYLAB and the manned MIR, that had since crashed back to earth to the MIDAS reconnaissance satellites – because of their high orbits- will still be orbiting our planet 20,000 years from now. Unless somebody uses them for target practice via an anti-satellite missile launched from a high performance supersonic jet fighter flying at 90,000 feet or more.

Touted as the 20th Century invention that made the current Internet revolution possible, communication satellites are more than just a technological conveyance that allow anyone to surf the web and send e-mails across the globe. To us current generation of satellite gazers / space bird watchers, communication satellites have become a major –if not the most dazzling- part of our observational targets. Like the ever growing family of Iridium satellites whose Teflon-coated high gain antenna reflects the ambient light of the moon and the sun into an optical spectacle that never cease to amaze even the most jaded amateur astronomer.

Orbiting satellites seem to arouse interest to the amateur astronomer’s community with the same enthusiasm as Charles Messier’s catalog of 109 objects. But unlike 18th or 19th Century astronomers (they’re pretty much amateurs back then because anyone who can afford to custom built his own astronomical i.e. really big telescope is automatically an astronomer), amateur astronomers today who chooses “space bird” watching has more than 8,000 –and growing- potential targets for observation. From the International Space Station, shiny Iridium satellites to the somewhat “transient light shows” created by manned space vehicles like the space shuttle whose light displays are always eventful even for the naked eye observer. From the shuttle’s launch into the desired “orbit window” dictated by the specified NASA mission to the shuttle’s brilliant re-entry back into the Earth’s atmosphere, a “light show” that could rival the best Leonid meteor shower of recent memory.

These satellites orbiting Earth has advantage to the novice amateur astronomer / prospective “satellite gazer” – other than their relatively close distance in astronomical terms- is that these objects are highly angular in shape with fine detail in comparison to the moon and other natural heavenly bodies visible in the night sky. With this in mind, you can use their angular and detailed structure as a test bed in computing the Raleigh Criterion i.e. resolution limit of your telescope system. See how it compares to the Canary Island based “Grantecan Telescope.” Or you can test out Wien’s Law or Blackbody Radiation principles in practice, especially if you are fortunate enough to live within driving distance from the company who manufactures the specific satellite you are observing. And if you can, be able to arrange a plant tour to see –and even touch- the satellite’s twin in the plant.

For those who are a genuinely “novice” amateur astronomer, you can check out http://www.heavens-above.com. The user-friendliness of this site is comparable to the latest help desk software. On this site, you can input the latitude and longitude of your observatory i.e. “home” (or is that rooftop) and you can search the heavens-above site for the various “satellites” that can be seen from your home and which part of the night sky you should point your telescope to. The heavens-above.com site is not only limited to observing artificial satellites, you can use the site to “ask” which part of the sky should you point your telescope from your house to see Mars, Jupiter, various stars and Messier objects etc. Also, you can check out the US Space Command’s web site at http://www.spacecom.af.mil/usspace. The US Space Command’s primary mission nowadays is to warn the space shuttle to avoid possible incoming meteor strikes and “space junk.” The US Space Command has the most advanced RADAR array in their Cheyenne Mountain complex that it can even “see” baseball-sized objects whose orbital path could hit the space shuttle. Or for a comprehensive list of satellites in current service, go to NSSDC Master Catalogue Spacecraft Query Form at http://nssdc.gsfc.nasa.gov/nmc/sc-query.html. Also check out the Satellite Tracking Web Page, which is an excellent source of element files and satellite links at http://staff.feldberg.brandeis.edu:80/~progrmer/satellite/satellite.html.

So goodbye and keep on watching the skies.

No comments: