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HomeTopicsSatellitesViewing Satellites
Viewing Satellites: An Exciting and Educational PastimeViewing satellites is an exciting challenge for some and a casual hobby for others. For kids and adults alike, a glimpse of a satellite is a chance to marvel at the technology that placed it in orbit.
Those who pursue the brief trail of light with a passion are just as curious about the purpose and type of object propelling itself through space. Spotting a satellite, a maneuverable object collecting and then transmitting data to some specified location on Earth, is often a magical experience.
Best Times for Viewing SatellitesIf you're outside during those special times before dawn or after dusk, chances are you'll see a satellite. The type you see may be involved in any number of activities, including:
Although rare, it could even be a military surveillance satellite.
Hundreds of satellites exist, and many are quite visible without the use of magnified lenses. By simply waiting and watching, you may see a small gleaming object moving slowing across the skies. It's not an airplane and it is definitely not a shooting star. It will track slowly to the naked eye, although at its true altitude it may be moving at 17,000 miles per hour or more.
The best times are about an hour after the sun sets and an hour just before sunrise. These viewing windows will vary according to season and location.
The first reason we can see satellites during these times is because one or more portions of them are projecting the sun's reflection. However, during daytime hours the surrounding atmosphere is too bright. Once we cannot see the sun anymore, the contrast of darkness makes a satellite visible. This is only temporary, as the satellite will eventually drop below the local horizon and fall within the Earth's shadow.
Light pollution can also impede viewing. That includes the glow from city lights on the horizon, the lamppost on the street corner or a neighbor's lighted front porch. Sometimes, mornings offer a greater advantage for observation with less interference.
It is possible to view some satellites during the daytime hours. Observers should avoid looking at the sun directly, as this can lead to irreversible eye damage. The danger increases with the use of binoculars or telescopes.
Recognizing a SatelliteObservers can identify three main characteristics when viewing a satellite:
Color changes can occur, although most satellites provide a white glare. Some produce other colors, including red and yellow. This relates to the surface finish and may be more obvious at the changeover point at the Earth's shadow line.
Equipment for Viewing Satellites from EarthIt's perfectly easy to see larger satellites without any special equipment. However, smaller satellites with a lower brightness magnitude are less visible. Exact locations require knowledge of longitude and latitude points at your precise location.
Binoculars are inexpensive and will certainly improve visibility. Drawbacks include a smaller viewing field and the fact that they can become quite heavy when held for long periods of time. Mounting them on a tripod also limits the flexibility in tracking.
Telescopes offer a wider field of vision and greater magnification powers. Again, tracking may be difficult without motor-driven assistance.
Viewing Satellites with Computer AssistanceSeveral software programs exist that provide off-line tracking. Some are free to download while others are in demo or shareware versions. Fully loaded tracking systems are usually affordable and offer an exciting opportunity to gather precise coordinates at any location.
Some Web sites provide free services for providing satellite viewing locations, times and probability of appearance.
Heavens-Above is an easy-to-use online tracker that's free for both anonymous and registered users. The site features a wealth of fascinating information that is customizable based on specific locations.
NASA's Human Space Flight site also provides a visual listing of flight times that can pinpoint city locations as well.
Keep in mind that at any location, the sighting might not occur. This could be due to weather conditions, but sometimes a satellite veers off its projected path.
Resources
Heavens-above.com (n.d.) Welcome to Heavens-Above. Retrieved January 23, 2008, from the Heavens-Above Web site: http://www.heavens-above.com/.
Johnston, Wm. Robert (2006). Observing man-made Earth Satellites. Retrieved January 23, 2008, from the Johnston's Archive Web site: http://www.johnstonsarchive.net/astro/satview.html. Satobs.org (n.d.) Beginner's Observing Guide. Retrieved January 23, 2008, from the Satobs.org Web site: http://www.satobs.org/satintro.html Science.nasa.gov (2000).J-Track Satellite Tracking. Retrieved January 23, 2008, from the Science@Nasa Web site: http://science.nasa.gov/. |
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