Stare into space on a clear, dark night and you’ll see them. Tiny dots of light moving across the sky. Some appear for a minute or so, others take several minutes to move from horizon to horizon. Many people have never seen them. Are they airplanes or meteors? No. Top secret military vehicles? Maybe. Aliens from another galaxy? Definitely not.
You’ve probably heard of airplane spotting. Welcome to the world of satellite spotting!
Since the launch of Sputnik in 1957, humans have been hurling tons of stuff into earth orbit. More than 2,500 vehicles have been launched and there are over 21,000 objects larger than 10 cm being tracked by NASA. Some of these objects are active satellites (communications, research, weather, spy, etc) while others are junk from launch vehicles. That’s a lot of stuff!
You can’t see the little objects, but you can definitely spot the larger stuff with the naked eye if you have a little patience and clear skies.
Celebrity Satellites: Hubble & The ISS
The two undisputed rock stars of satellite spotting are the Hubble Space Telescope and the International Space Station (ISS), the largest manmade object in Earth orbit. When the position of the sun and the orbit of these satellites are just right, they can easily be seen. The ISS can appear as bright as Venus.
Don’t limit your spotting to these two objects. There are hundreds of other viewable satellites!
What does a satellite look like from earth?
Due to poor low-light sensors in video cameras, there aren’t many good examples of satellite flyovers on the internet. I created an animation that approximates what you can see when watching a large satellite like the ISS. Most viewable satellites won’t appear quite as bright as the one in my example:
How To Spot Satellites
Satellites don’t have exterior lights. Even if they did, the lights wouldn’t be bright enough to see from the ground. When you spot a satellite, you are actually seeing reflected sunlight. The ISS has a huge array of reflective solar panels that reflect a lot of sunlight, making it easy to see.
Unless you are spotting the super bright ISS, you need to be away from city lights. Head out to the country. The best time to spot satellites is just after dark or before dawn when the sun is a few degrees below the horizon. During the middle of the night, the earth blocks the sun from the satellites as they pass overhead making them invisible.
Spotting Method One – Grab A Seat & Enjoy!
About 45 minutes after sunset, grab a lounge chair, stare up at the sky, and watch the stars. Within a few minutes, you’ll spot a “star” that treks smoothly across the night sky. Remember, airplanes have flashing lights; don’t confuse them with satellites. As satellites fly overhead, they often appear and disappear as they move in and out of the sunlight. Some will be very dim while others are quite bright.
On a clear, chilly evening earlier this week, my kids and I stood in the backyard to spot satellites. We counted eight satellites and one meteor within 15 minutes. Soon after, we lost count. My 10 year-old was ecstatic when he learned that some of them could be spy satellites. With a little coaching (“No, that one’s an airplane”) the kids quickly became expert spotters. Their eyes are a lot better than mine.
Spotting Method Two – Find Specific Satellites
This takes a little planning and research. There are several online tools available to help you spot your favorite satellite; even spy satellites. NASA’s Spot The Station (as well as most other satellite spotting tools) will tell you the date, time, direction (azimuth), and elevation where the satellite will appear in your area.
Check out the sighting data for the ISS on November 12th in my city:
Here’s what those numbers mean:
The ISS will become visible at 6:15 AM for 4 minutes. It will appear in the west-northwest sky at an elevation of 25° and disappear in the north-northeast at an elevation of 10°. Use a compass to determine the direction to look. The iPhone has a built-in compass that works great. Android phones, like the Galaxy, can be used with the addition of a compass app.
Figuring out the elevation:
Elevation is the measurement in degrees above the horizon. The horizon line has an elevation of 0°. Straight up is 90°. Using an outstretched arm, you can estimate degrees of elevation. Your three middle fingers held together is roughly 5°. Stretching your index and pinky finger apart will measure about 15° of elevation. It’s not exact, but it will get you looking in the right part of the sky!
That’s all there is to it! If you’re looking in the right direction, at the right time on a dark, clear night, you’ll see what you are looking for.
Satellite Spotting Tools
Here are my favorite tools for satellite spotting:
- NASA – Spot The Station: Easy to use. Spot the ISS and resupply ships. Text and email alerts when the ISS or resupply ships are visible!
- The NASA App (iOS & Android versions). Required app for every space geek!
For Advanced Spotters:
- Heavens Above: Viewing predictions for dozens of satellites and Iridium Flares.
- NASA SkyWatch: Viewing times for any location on Earth for the ISS and dozens of other satellites. Requires Java Runtime Environment which may cause security warnings.
Who needs a telescope?
If you have a DSLR with a really long lens or a full size “megazoom” camera, you can actually take pictures of the ISS! I captured this image of the station with my Canon PowerShot SX50. Settings I used were: ISO 200, f6.3, 1/320 sec. Zoom was set at 1200mm (equivalent).
Any luck spotting a satellite?
Have you seen a satellite or tried looking for them? I’d love to hear about your stargazing experiences. I’m also interested in what websites, tools, or apps you use to help spot them. Be sure to leave your comments below!
YouTube user Captain Jack captured the ISS in this 2005 video. This is a great example of how bright the ISS can appear, even when near city lights and a bright moon.