I realize that this is going to be old hat for some but I keep seeing a lot of repeats when it comes to people reporting UFOs. As a result, I wanted to start a column describing
various identifiable objects that are often reported as UFOs. It is my desire that those reading this article may go a little farther into researching their satellite UFOs before filing an actual report.
Satellites vary in appearance and brilliance due to many factors. One can go to the “Heaven’s above” web site and obtain data for any location in an easy to read format. The web site only reports satellites that will be bright enough to be seen and those with known magnitudes. Sometimes faint satellites catch the sun just right and are much brighter than they are predicted to be. If you have a specific satellite you are interested in, you have to look it up. NASA has J-Pass but that has a more difficult system to work with. If Heaven’s above does not include your satellite, J-Pass probably will (assuming you select “ALL” in the options). A final site is Calsky. It is quite good in listing all the satellites making a pass for an evening.
Orbits and angular speed
Satellites travel in different orbits and, as a result, their angular speeds are going to be different. The higher the satellite, the slower it will move across the sky. Most people are familiar with the International Space Station (ISS) or Space shuttle. However, some satellites in even lower earth orbit practically race across the sky. These are usually short lived satellites and rocket boosters. Satellites in higher orbits practically crawl across the sky at a very leisurely pace. I recall observing one polar satellite around second magnitude that took 15-30 minutes to make it across the sky. Most often, these satellites are not very bright and at the limit of naked eye visibility.
In May 2009, an amateur astronomer and a few others reported a low earth orbit (about 125 km altitude) rocket body (See SUNlite 1-2 p.16) as a UFO. This was the rocket that had launched the TMA capsule that had docked with the International Space Station (ISS). They assumed that because it was moving faster than the ISS (which was in the sky at the time), it was not a satellite. Unfamiliarity with the concept of orbits and angular speeds misled the observers into thinking they had seen something exotic rather than a mundane object in a different orbit.
The ISS and Space Shuttle
The most well known of the satellites is the ISS. It is often very bright and rivals Venus in brilliance. When the shuttle is not docked and nearby, the two can put on quite a show for the casual observer.
In September 2009, the two made a great display for observers (See SUNlite 1-4 p. 7). Despite observers having plenty of information about the pairing of the shuttle and ISS, people still reported them as UFOs. It did not help that the shuttle was dumping waste water at the time. This confused some observers into thinking they were seeing a UFO and not the space shuttle. In one instance, the observer’s companion became hysterical about the UFOs and he had to calm her down!
The Iridium Satellite constellation consists of 66 satellites operating in polar orbits. Their Main Mission Antennae (MMA) can catch the sun’s rays and cause a spectacular flash. This produces an “Iridium Flare”. Normally, the satellite is not visible and hovers around magnitude +6. However, when the sun strikes them correctly, they can peak at a brilliance as high as -8th magnitude, which is much brighter than the planet Venus. Some people report seeing these flares during the daytime. Even at -8, a daytime flare is a challenge. Iridium flares are brief but the satellite can be seen a few seconds before and after in a good sky. Some UFO reports might refer to them as meteor-like but “too slow” to be a meteor.
The NOSS (Navy Ocean Surveillance System) triplet is a group of three satellites that operate in a triangular grouping.
They are not very bright and it takes a keen eye to see them or they have to catch the sun just right. People, who report these usually have dark skies. However, some have seen them flare up to as bright as Venus, which must have been an alarming sight. Imagine three bright objects moving across the sky in triangular formation. I am sure such an event created some UFO reports. Over the past few years the “triplets” have lost their configuration and they are no longer in the triad formation they once were. They now lag behind each other and make similar tracks across the sky a minute or two apart.
The third generation NOSS satellites now are launched as pairs. I had observed NOSS 3-1 A and C back in July of 2002. They varied between second and fourth magnitude and it took a request from the SEESAT bulletin board to get an ID. At the time they were called USA 160 A and B. It was quite eerie as the two satellites passed across the sky. It gave the impression of one satellite chasing the other!
Geosynchronous and Geostationary satellites are similar but not quite the same. Geostationary are satellites orbiting above the Earth’s equator at a speed equal to the Earth’s rotation. Geosynchronous are located in an orbit not quite above they equator. However, they can maintain position over a certain area of the globe because of the nature of their orbit. These kinds of satellites are often too faint to be seen. However, when they catch the sun’s light just right they can appear as a second or third magnitude star. The only way you can determine they are not stars is they do not move the way the stars do due to the Earth’s rotation.
I have seen several Geostationary satellites flare up over the years during my astronomy outings. Sometimes they are visible for several minutes and then fade away.
I remember one event during the Winter Star Party in 1997, that was visible for a significant period of time and fluctuated between magnitude +2 and +3.
The Ogre and Satellite Glints
Back in the mid-1980s, I read in Sky and Telescope about something referred to as the “Aries/Perseus Flasher” or “OGRE (Optical Gamma Ray Emitter)” . It had been reported by veteran meteor observers associated with a Canadian astronomy group. They had observed a bright flash of light near the Pleiades star cluster and began to monitor this area of the sky for several months. After reporting they had seen it several times, Sky and Telescope encouraged observers to monitor/photograph the sky. I recall taking images of the area several times especially when the group managed to photograph the object. The reports of the OGRE caught the attention of quite a few astronomers.
Many observers attempted to see the OGRE but were unsuccessful. However, it was noted that flashes of light did not just happen in the region noted and observers had been reporting light flashes in other parts of the sky. Work by Paul Maley identified the source of the light in the photograph as being a “glint” from Cosmos 1400. Maley also determined that Molniya-orbit satellites were the likely source of several of the observations of the OGRE. Normally, they were very faint objects (below 9th magnitude) but, under the right conditions, they could create a bright flash to an observer on the ground. Eventually, Maley positively identified six of the observations as satellite glints. The results of this extensive investigation was published in the September 1st, 1987 edition of the Astrophysical Journal. The OGRE had become identified as something mundane.
Satellite glints and satellites that tumble are not uncommon. When the sun hits them just right, they can flare up to a brightness that makes them noticeable. The lesson here is that just because no satellite pass is listed does not necessarily mean that it is not a satellite. If you need help, there are plenty of resources on the web and satellite observing groups like SEESAT are always willing to lend a hand.
One other item that occasionally pops up in UFO reports are satellite/rocket/spaceship events that involve venting fuel or exploding in orbit. These can be quite spectacular as the satellite/rocket can become a large glowing object that takes on a unique shape that confuses observers. A good example occurred on August 31, 2004. It was widely visible on the east coast of the US at a time of night that favored a large number of observers. Some reported an angel-shaped cloud, while others gave different shapes depending
on their interpretation of what they saw. One report in the NUFORC database that caught my eye was a “college professor” in Gulf Breeze, Florida, who was also an “amateur astronomer”. People, who use the label of “amateur astronomer” and file UFO reports without a bit of research do not really qualify as amateur astronomers. I refer to them as sky watchers or novice astronomers. In my opinion, an experienced amateur should attempt to identify his observation before filing a UFO report. Space.com identified this the following day on their web site. Apparently, this “sky watcher” was more interested in filing his UFO report than seeing if it was something that could be explained.
Be thorough in your search
The one thing I have learned about UFO reports that turn out to be an object in orbit is that you have to be diligent in your search. I once was surprised to see a second magnitude satellite make a pass even though it had not been listed on Heaven’s above! Their database had no magnitude listed for it and, as a result, they do not list it in their satellite passes for the night. The general rule of thumb is that if it looks and acts like a satellite, it probably is. Just make sure you take your time to check all the resources and don’t be afraid to ask for help from experienced satellite observers.
Quelle: SUNlite 3/2010