Satellite Watching from the Sahyadris


Experienced hikers know that the Sahyadris provide an amazingly clear view of the night sky. Far from the polluted air of the cities, the view of the stars and other heavenly objects from much of the Sahyadri range is truly amazing.

While there is plenty of scope for astronomical observations during overnight hikes, this website is about a little-known but equally exciting hobby ... observing man-made earth satellites in orbit! And you don't even need binoculors to locate them since they are visible very clearly to the unaided eye! All you need to know is precisely where to look and when to look.

By following the steps outlined here, you can make your next overnight hike all the more interesting.


STEP 1:

First you need to obtain the GPS coordinates of the sites in the Sahyadris that you would be hiking to. The GPS coordinate data is important as it determines the locations and timings to be used for observing the satellites. The GPS coordinate data are available on this website in the form of the Sahyadri GPS Database. Download and save this database on your computer before continuing with the rest of the instructions.

Click here to access the Sahyadri GPS Database


STEP 2:

The next step is to find out when and where you should look in order to observe earth satellites. The link below takes you to a website which utilizes the GPS data you saved in the previous step as input. When you click on the link below, you will be asked about the latitude and longitude from where you will be observing the night sky, along with the earth satellites that you are interested in observing. For starters, the International Space Station is highly recommended because it is very large and impressive, even with the unaided eye. If this will not be over your hiking area during the dates you selected, choose other satellites.

When selecting satellites, give preference to those that have a high level of illumination (magnitude value). Note that the magnitude scale is unusual. The higher the number, the smaller is the magnitude. Negative numbers are the highest magnitude (eg: magnitude 3, magnitude 0.5 and magnitude -2.3 are in increasing order of brightness). Anything that is of negative magnitude will be easily visible to the unaided eye. Also select satellites that pass overhead, instead of just skimming the horizon.

After you click on the link below, the home page of that site will appear on your screen. Scroll down and select "Anonymous User" and then select "Enter your coordinates manually"

Click here to access the Satellite Tracking website


STEP 3:

Note down the times, dates, azimuth of rise, azimuth of set and names of all the satellites that would be visible during your hike. (If you are unfamiliar with azimuth, it means the direction in terms of North, South, East or West, except that it is a lot more precise. North is 0 degrees, East is 90 degrees, South is 180 degrees and West is 270 degrees. So if you get an azimuth of, say, 223 degrees, you know where on the horizon it corresponds to, relative to the four main points of the compass)


STEP 4:

Before you leave on your hike, set the EXACT time from a reliable radio station or other means on your watch. It is preferable to use a digital watch since even the seconds matter!


STEP 5:

During your hike, at the exact time specified, look in the general direction of the horizon where the satellite is supposed to appear. If the day is cloudless, you will see it appear almost to the second of the predicted value and it will move across the night sky just as predicted!


Useful Tips

  • Most satellite observations are possible around sunset time or sunrise time. This is because in order to be able to view satellites from earth, the observer must be in darkness and the satellite must still have sunlight shining upon it.


  • Observing at the predicted time is very important. You will miss the observation even if you are as little as 10 seconds late! The satellites you can observe are low earth orbit satellites. The time they take to travel across the night sky lasts only a minute or two.


  • It is amazing how accurately the locations of satellites can be predicted. Whenever I observe a large satellite such as the International Space Station, it appears exactly where and when it is predicted to appear. Such a satellite appears to the unaided eye as a very large star moving rapidly across the night sky.


  • Earth satellites appear different from shooting stars (or small meteors) in the sense that their brightness does not flicker as they move across the night sky. Also, the apparent speed of movement of these satellites is a lot slower than the typical shooting star.


  • In very clear skies after dusk, you can observe as many as three or more earth satellites simultaneously!


  • There are thousands of satellites in orbit today. If you miss one, simply observe the next one on your list.


  • It is even possible to view the Space Shuttle when it is in orbit. The same website given above also provides observation data for the Space Shuttle. This shows up just as bright as the International Space Station. When the two are docked, you get one of the brightest objects in the night sky!