This morning I captured an Iridium Flare on video. What, you might ask, is that?
There is a constellation of 66 spacecraft orbiting Earth which make up a world-wide satellite phone system. The system provides coverage all over the Earth. The spacecraft look like this. Besides having two solar panels, barely visible in this image, there are three highly reflective rectangular antennae. These antennae communicate with phones on the ground and with other Iridium satellites.
The antennae are also excellent mirrors which reflect sunlight in orbit. Those reflections sometimes pass over the surface of the Earth as a bright patch of light about 10 km (6.1 mi) wide. If you know when and where to look, the reflections can be seen easily at night and sometimes in broad daylight. They last only a few seconds. They can be many times brighter than Venus or Jupiter. This morning one of the brightest possible reflections, or flares, passed directly over me. I wanted to try recording it on video.
When and Where to Look
There are websites that provide this information. An easy one to use is Heavens Above. You will need to set your location by using the Change Your Observing Location link at the left side of their window. Once you’ve done that, it should appear in the top right of the window. Bookmark the url for later visits. Notice the many choices at the left of things to explore.
Next click on the link at the left side of their window called Iridium Flares in the Satellites category. You should soon see a list of upcoming flares visible to you at your site if there are any. Note the Brightness column. Pick one with a large negative magnitude. Those are the brightest. Click on it’s link at left to see more. You will see a star chart and details about the flare. The satellite track is shown and a marker for the location of the bright flare along that track.
What I Expected This Morning
Heavens Above gave me this chart for this morning’s flare. It was going to be near Orion’s shoulder at 6:30:50 am.
At that time, the sky was going to be well into twilight. Stars wouldn’t be visible. So, I went outside a little before 6 am to photograph Orion in order to know where to point my video camera later. Orion was exactly where I expected. I zoomed, cropped, and enhanced the image to match the chart above.
Here are the details of the flare provided by Heavens Above. It provided the altitude and azimuth for the video camera pointing directions.
I set the video camera to point at the spot in the bright sky. Just before the flare was to shine, I started the recording and looked up to watch. There it was, incredibly bright at magnitude -8. It brightened and faded within 3 or 4 seconds. I stopped the camera and went inside to check the result. Got it!
For best viewing, watch this video on a desktop monitor and set to full-screen HD. Look just barely right of center at the 5 second time. It is very brief. What do you think of that?