Category Archives: AstrOGears

The AstroLabe

We are living in a modern age, satellites positioning systems have automated navigation of the seas, skies and continents. Time is measured precisely by using atomic clocks. Modern telescopes are controlled and targeted using modern automated computer drive systems. All these modern technologies today have far outpace the time keeping and the basic navigational of  the past scientific instruments.  Well, lets go back to the past and have a look at;

The  Astrolabe – By Bruce Levell


“For about 500 years the astrolabe was probably the most sophisticated scientific instrument in the world. True to its etymology (from the Greek word for “star finder” or “star taker”), the astrolabe is a model of the sky, showing the positions of the Sun and main stars at any time of the day or night throughout the year. It can be used to:

  • Navigate, since the positions of the stars at a known time reveal the observer’s location on the globe and the direction in which to travel;
  • Calculate setting and rising times for the Sun, and hence prayer times or the length of the day, for and day of the year;
  • Determine the likelihood of a new Moon being sighted on any particular day;
  • Tell the time from the observed positions of the Sun or stars.

In addition, astrolabes were frequently used to cast horoscopes.

A planispheric astrolabe is based on a two dimensional map of the sky, rendered in most cases by stereographic projection. Such a projection can be imagined as the view of the sky that would be seen by an observer standing on the south pole and looking straight “down”, through the solid earth, at the northern sky. The observer would thus see a circular sky, centered on the north celestial pole.

Normally, astrolabes take the projection of the Tropic of Capricorn (the line of latitudes at 23.5 degrees south) as the edge of the circular map. Other key latitudes – the Equator and the Tropic of Cancer – would project onto this view as smaller concentric circles.

A real observer, of course, has no x-ray vision and only sees part of the sky at any one time – and part that he does see varies with his latitude and the time of the day. The markers of the astrolabe solved this problem by fitting each astrolabe with a series of removable plates (Arabic: safiha), each showing a polar grid and horizon for a small range of latitudes. By rotating the star map above these plates, one can simulate the rising and setting of stars against the fixed horizon and thus the sky view at a particular latitude. This “rete” (Arabic: ankubat) was typically fashioned as a beautiful frame that carried star names without obscuring the underlying grid lines.

The astrolabe was not primarily an observational instrument, although on its reverse side it was equipped with an alidade, or sighting rule (Arabic: alidada), along which a star’s altitude or bearing could be determined. Some astrolabes were modified for use at sea; they were made heavier or peMariners Astrolaberforated so as to reduce the chance that instrument would be blown by strong winds on the deck of a ship.

The astrolabe was probably perfected by Arab astronomers, such as Muhammed Musa al Khwarizmi in the early 9th century, building on Greek understanding. The earliest surviving examples, however, date from the late 10th century. The astrolabe fell out of use in the 17th century in the West and somewhat later in the East, succumbing to more accurate observational tools and printed astronomical almanacs.

Astrolabes are still made today in Afghanistan and India for tourist market; they can even be found in Oman in Muttrah souq. But these are often crude imitations of the real thing, which was not simply an accurate scientific instrument but an object of great beauty. Perhaps the most beautiful surviving astrolabe is the spherical one signed “work of Musa year 885” (i.e. 1480-1 CE) pictured above.

They are different types of astrolabes. The spherical astrolabe (top) is generally acknowledged as the most beautiful of its kind. It dates back to 1480 CE. Conventional astrolabes (bottom left and right on above picture) were flat and consists of rotatable frames and removable, engraved plates.

Disassembled 18th century astrolabe

Some pictures of Astrolabes: (click to view in full size)

museum of Islamic science and technology   museum of Islamic science and technology   museum of Islamic science and technology

More about Astrolabe:

To Be Continued later  🙂

Apple iPhone 4 Goes to Space

AstrO Gears Product showcase: Apple iPhone 4                                     AstrOceanOmy Store


Product Features Description

  • iPhone 4. The fastest, highest-resolution iPhone
  • FaceTime
  • Retina Display
  • Multitasking
  • HD Video Recording and Editing
  • 5-Megapixel Camera with LED Flash
  • Astronomy Edition 🙂

Yeah! The most amazing feature in iPhone 4 is the Gyroscope built-in. Which makes the iPhone 4 Astronomy edition.

I’m including iPhone 4 as one of my AstrO Gears product. Why! Just see below… I will include more features of this gear later on.

Last year Father-Son Team lunched iPhone 4 into Space with weather balloon. They have used an insulated craft, weather balloon, iPhone 4 and a HD video camera to enter the space and film down the whole process. iPhone 4 was used to locate the location of the craft. Check out the video>>>

iPhone in Orbit


Interesting right!

The next surprise is that iPhone 4 this Month will be taken aboard the International Space Station via STS-135 to help conduct ground breaking experiments. Odyssey Space Research LLC, of Houston, TX, has developed an iOS application that will take advantage of the iPhones built-in mechanisms.

The experiments will perform onboard the US. National Laboratory on the International Space Station (ISS)


In an excerpt from their official press release, Odyssey states:

The SpaceLab for iOS app will utilize the innovative features of iPhone 4, including the three-axis gyro, accelerometer, Retina display, cameras and A4 chip, for space-based research. The crew will conduct various experiments to collect data which could one day find use in practical applications, such as the recovery of navigation information for a spacecraft that might be “lost in space.

SpaceLab for iOS 

Four experiments are planned, click on the image above to read more.

As stated by Odyssey Space Research:When the experiments are completed, both iPhones will be returned to Earth. The first opportunity for return will be on a Russian Soyuz vehicle in the fall of 2011. Flight data from the experiments are expected to be collected, analyzed, and then shared via this app on the App Store.

The launch target for STS-135 (Orbiter Atlantis) is set by  July 8, 2011. 🙂

What are you waiting for! Download the application now.

Need an iPhone! It’s available in AstrOceanOmy Store.

Click here for more AstrO Application for iOS from NASA

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Celestron SkyScout

AstrO Gears Product showcase: Celestron SkyScout Personal Planetarium. AstrOceanOmy Store

“This is the device amateur stargazers have been waiting for since, well, Galileo..”  Popular Science Magazine


SkyScout is a revolutionary handheld device that uses advanced GPS technology with point and click convenience to instantly identify over 50,000 stars, planets, constellations and more.


SkyScout Features:

  • Identify: Simply point the SkyScout at any star in the sky and click the “target” button. The SkyScout will instantly tell you what object you are looking at.
  • Locate: To locate a star or planet, select the objects name from the menu and follow the directional arrows through the viewfinder. SkyScout tells you when you are on target. It’s that easy!
  • In addition, the SkyScout also features a ‘Tonight’s Highlights’ function which provides you with a customized list of the 20 best objects you can view for your exact date, time and location anywhere in the world.
  • Learn: Once you have targeted an object the real fun begins. The SkyScout includes entertaining and educational audio and text information, including facts, trivia, history and mythology about our most popular celestial objects. If you locate a star that is part of a constellation, the SkyScout will even talk you through every star within that constellation along with providing a detailed onscreen map on the whole constellation. A fun learning tool for all ages, the SkyScout personal planetarium puts the knowledge of an expert astronomer in the palm of your hand.
  • Click here for more from Celestron website.


Not to forget that the Celestron SkyScout Personal Planetarium is the “Official Product” of the International Year of Astronomy (IYA) 2009!

I already purchased mine since long time back and would like to share some pictures:.

photo 1  photo 2

photo 3  photo 4

While opening the box, I’ve noticed something strange and funny in the package 🙂  . I’ll come up with more details in the next post. Please visit for updates.

SkyScout is available for purchase in AstrOceanOmy Store .


Anyone in Oman who would like to purchase, please contact me.

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