When I was processing the photo of the Magellanic Clouds, I noticed that four of the photos had a light trail going across it. As these are long exposure photos, a light trail means a travelling object.
There are many types of illuminated travelling objects in the night sky. They can vary from natural objects to different types of man-made objects.
1. Meteors
The only extra-terrestrial natural object to make star trails on a long exposure photo like this one is a meteor. During a meteor shower, you will be able to capture many trails like this during the span of an hour. One of my wishes for a very long time has been to capture a meteor shower on camera.
2. Airplanes/helicopters/drones - flying machines
There is a host of man-made objects that are not necessarily space borne that can cause a light streak. These include all the flying machines invented by man. In the past, these were limited to airplanes and helicopters. But thanks to retail access to various hobby flying machines, these now include drones and at least in two cases for me, kites that were fitted with LED bulbs. It is not unusual to have fireworks captured in your long exposure shots as well.
3. Bioluminescence
There are cases where bioluminescent insects like fireflies causing light streaks in long exposure photographs. But they are almost never straight or near-straight lines.
4. Artificial satellites
One of the most common objects to be captured as trails on a long exposure night sky are satellite flares. Compared to the distant objects of the night sky (i.e. stars), they travel very fast. There are many types of artificial satellites as well, the most common to be spotted are called Iridiums. Iridiums belong to a collection of 72 satellites. In addition to this, there are various communication, military and scientific satellites that are orbiting the Earth. As of now, there are nearly 1500 artificial satellites that orbit us. In addition to the regular satellites, one of the most iconic man-made space objects that are spottable from Earth is the International Space Station.
When I looked at the photo I took, I was trying to figure out what it exactly was. While was wishing it to be a meteor, there was one main thing that stood out that hinted otherwise; the time of the trail. While meteors do cast trails, the trail I had on the photo was visible across 4 photos of 10 sec exposure each. This means the meteor should've been visible for around 40 seconds or more. However generally a meteor doesn't cast a streak for that long; unless they are really large, a meteor shines for only about 5 seconds at most.
My next guess was that this then is a satellite. However which one? While Stellarium does provide a plugin which lists known satellites and their orbits, the sky is littered with them, that without knowing the precise time and the location, it is virtually impossible to track it.
After trying multiple times, my take is that what I captured is either a satellite of the Globastar group, which provides satellite communications similar to the Iridium group, or one from the NOSS - Naval Ocean Surveillance Satellite group, which as the name implies, does naval surveillance.
I guess I'd have to wait a bit more for my meteor.
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| The light streak - Composite shot of 4x10s |
There are many types of illuminated travelling objects in the night sky. They can vary from natural objects to different types of man-made objects.
1. Meteors
The only extra-terrestrial natural object to make star trails on a long exposure photo like this one is a meteor. During a meteor shower, you will be able to capture many trails like this during the span of an hour. One of my wishes for a very long time has been to capture a meteor shower on camera.
2. Airplanes/helicopters/drones - flying machines
There is a host of man-made objects that are not necessarily space borne that can cause a light streak. These include all the flying machines invented by man. In the past, these were limited to airplanes and helicopters. But thanks to retail access to various hobby flying machines, these now include drones and at least in two cases for me, kites that were fitted with LED bulbs. It is not unusual to have fireworks captured in your long exposure shots as well.
3. Bioluminescence
There are cases where bioluminescent insects like fireflies causing light streaks in long exposure photographs. But they are almost never straight or near-straight lines.
4. Artificial satellites
One of the most common objects to be captured as trails on a long exposure night sky are satellite flares. Compared to the distant objects of the night sky (i.e. stars), they travel very fast. There are many types of artificial satellites as well, the most common to be spotted are called Iridiums. Iridiums belong to a collection of 72 satellites. In addition to this, there are various communication, military and scientific satellites that are orbiting the Earth. As of now, there are nearly 1500 artificial satellites that orbit us. In addition to the regular satellites, one of the most iconic man-made space objects that are spottable from Earth is the International Space Station.
When I looked at the photo I took, I was trying to figure out what it exactly was. While was wishing it to be a meteor, there was one main thing that stood out that hinted otherwise; the time of the trail. While meteors do cast trails, the trail I had on the photo was visible across 4 photos of 10 sec exposure each. This means the meteor should've been visible for around 40 seconds or more. However generally a meteor doesn't cast a streak for that long; unless they are really large, a meteor shines for only about 5 seconds at most.
My next guess was that this then is a satellite. However which one? While Stellarium does provide a plugin which lists known satellites and their orbits, the sky is littered with them, that without knowing the precise time and the location, it is virtually impossible to track it.
 | ||
| Satellites near the south pole |
After trying multiple times, my take is that what I captured is either a satellite of the Globastar group, which provides satellite communications similar to the Iridium group, or one from the NOSS - Naval Ocean Surveillance Satellite group, which as the name implies, does naval surveillance.
I guess I'd have to wait a bit more for my meteor.
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