Venus is a much more observable object than Mercury
in comparison, for it is very easily visible and shows a large disk. Its great brilliancy is actually a considerable disadvantage, because when seen at night its glare masks the detail and produces false effects.
The only way to solve the difficulty is to observe Venus in the bright dawn or sunset sky, according to the elongation.
[hide][top]Observing the Planet Venus
Finding a planet by daylight may sound a difficult task, but Venus is so bright that it can, under first-class conditions, be seen with the naked eye. Care must be taken due to its proximity to the sun
If its approximate place is known (and it can be worked out easily using the positions in software
or using a goto
telescope), this region of the sky is swept over slowly, using the lowest possible power to provide a wide field of view. Once the planet is found, the magnification can be stepped up.
conditions are often bad, especially in the early evening, and this means that powers higher than X100 may be less effective than lower magnifications. It is essential to have a sharply-defined disk, and if this is not possible with even a low power it is clearly hopeless to observe at all. All things considered, the Planet of Love is often a very frustrating object to observe easily.
Filters that may help - UV/IR and similar planetary filters
There are several interesting phenomena to look for while Venus passes through an elongation. For obvious reasons the evening apparitions are likely to be better observed (it takes a good deal of resolution to exchange a warm bed for the chill of a winter dawn), and these begin when the planet is a shrunken disk just past superior conjunction. As it swings out to maximum elongation the phase lessens and the disk slowly expands, the dusky shadings, if any, becoming visible with more certainty. Because of the large variation in the diameters of both Venus and Mars
, some observers adjust the scale of their drawings accordingly. The normal practice is however to keep to a standard size, a diameter of 2 inches being suitable. As a general rule, always make drawings too large rather than too small.
The Venusian markings are usually so obscure that it is very hard to make a representational sketch. One good way is to use a very soft pencil, smudging the marks with a finger
and adjusting their contours with a putty rubber.