These are situated at some great distance from the earth (the stars being appreciably further away than the eight known planets). All move – relative to the earth – in an east to west direction. They will thus appear to “rise” and “set”, like the sun, and move at a similar sedate speed. Over a long duration (e.g. an hour) this motion can easily be confirmed by reference to some fixed point on the ground, but of course the stars do not move relative to one another, and so if no reference point is available such motion will be difficult to judge.

Stars have differing brightness (called stellar magnitude) – the lower the rating, the brighter the body. While bright stars seemingly have an angular size, every single star is much too far away for the human eye to see it as a rounded shape. It is purely a point source; the illusion of shape is, however, a very common one. Furthermore, the mind equates brightness with proximity; hence changes in brightness (due to atmospheric factors) may be mistakenly interpreted as a “UAP” repeatedly approaching and receding from the witness along a line-of-sight path. The same illusion is also reported in UAP reports involving planets (see below).

There are many other optical illusions involving the stars. A principal one is called Autokinesis. Here a bright light (the star) appears to move in relation to the dark background because of the lack of reference points. It will seem to dart about erratically, but in fact the distance covered is never more than a few times the diameter of the full moon. This effect can be experienced by anyone, and it has nothing to do with how good or bad one’s eyesight is. It can be startling.

Naturally, the presence of clouds in the sky can be a further complication. Here their relatively fast movements cause a motional illusion with the stars. It is a similar effect to the one you experience in a stationary railway carriage as a moving train passes by and causes the illusion that you, in fact, are moving as well. Clouds may also obscure a “UAP” (star) that has been visible for a long period, making it seem to “streak away at tremendous speed” or “go out like a light bulb” (both common descriptions by witnesses who are victim to this effect). If the sky overhead is cloud free it is easy for an observer not to relate the disappearance to the presence of cloud. It is a simple matter to isolate accounts that refer to stars.

Telltale signs: Long duration (up to several hours in many cases) and slow motion relative to the earth (excluding all random, illusory motions which will not affect the apparent overall motion). You should immediately suspect anything that was visible – more or less in the same place – for an hour or more.

Resources: In order to identify a particular star you will find plenty of help at a large bookshop with an astronomical section. Astronomical computer programs can generate even more precise information for any time or location. Online interactive planetariums on the web allow displaying sky maps as viewed from a given location at a specified time and date.
e.g.: http://www.astronomy.com/asy/stardome/default.aspx
http://www.fourmilab.ch/yoursky/

 

Another factor to consider is the flashing that stars sometimes appear to demonstrate. This is caused by disturbance in the atmosphere and is more pronounced near the horizon (where heat from the ground rises to cause turbulence). Stars can appear to change colour dramatically or more slowly (often following a red-green-blue sequence). This often results in the affected body resembling a stationary aircraft or helicopter! Consequently this “flashing” or “pulsating”, as witnesses often describe it, should not be a problem if the telltale signs are present. This can also enhance the autokinesis effect.

Planets are very similar to stars in appearance, except that because they are relatively close to the earth they move against the star background. This effect, however, is so slow that it is only visible over a number of nights; this relative motion will not, therefore, be seen in one single observation and for a one-off sighting planets will look like bright stars.

Their brightness does of course vary, according to how close they are to the earth at the time. There are really only four planets which act as feasible suspects for a UAP sighting. Saturn only rarely becomes very bright, but can sometimes appear so (up to a maximum magnitude of +0.43). Jupiter does, however, often appear extremely bright (maximum magnitude –2.49), and therefore large in `size’. Both these planets can take on a yellow tint. Mars as most people know, is reddish and becomes very bright every two years or so for a few weeks (reaching a maximum magnitude of -2.91). However, it is Venus (which can reach magnitude –4.60 in some situations) which is the archenemy of the UAP researcher. It can be so brilliant that it seems blue/white.

All four of these planets can cause UAP sightings, but Venus is certainly the most common culprit. This is because it is very bright twice a year – once in the evening and once in the morning. Mercury is so close to the sun that it is visible only briefly around sunrise or sunset (maximum magnitude –1.9), and is often thus swamped by the glare of the sun. The remaining, more distant, bodies – Uranus, Neptune and Pluto – are too dim to be seen by the unaided eye.

All the effects mentioned about stars also relate to planets, but often more so as they can be exceptionally bright. Venus at its most brilliant is a spectacular sight indeed. The difference is that since they move relative to the stars they can suddenly `appear’ in the sky if it has been cloudy for the previous few nights or if one only goes out for a few moments at a particular time each night. After several nights of viewing an ordinary sky Venus, or Jupiter, could suddenly be there, having risen on the horizon at that moment on that night. Naturally some people suspect these wanderers (as the name planet means) of being an intruding UAP.

Two planets (Jupiter and Venus) were, in 1975, by chance positioned close together in the sky. This proximity lasted just a few days but gave rise to spectacular UAP sightings on the first clear night of this conjunction.

Telltale signs: The same as for stars, and also that the planet will be visible in a slightly different relative position over the next few nights. Venus is often reported as a “cross shape”, and Jupiter or Venus as a “gigantic ball” – all optical illusions due to the excessive brilliance. Such shape illusions are much more common if a witness is viewing through binoculars or window glass. Aberrations in these can lead to all kinds of distorted shapes and a magnified image. A common one for Venus is “a dagger in the sky”. Duration (as with stars) can be up to an hour or more.

Resources: In order to identify a particular star or planet you will find plenty of help at a large bookshop with an astronomical section. Astronomical computer programs can generate even more precise information for any time or location. Online interactive planetariums on the web allow displaying sky maps as viewed from a given location at a specified time and date.
e.g.: http://www.astronomy.com/asy/stardome/default.aspx
http://www.fourmilab.ch/yoursky/