With small phases (Less than 0.2), when Venus has a narrow crescent. Observation in phase 1 and 3 are difficult because of proximity of Venus to the Sun, so it can be observed only during the day. Find planet day is easy if the telescope is equipped with ekvatorialnoy mount. Otherwise, to approximately calculate its position in the sky and ‘catch’ it in the telescope, placing the smallest increase. Around the time naibolyshego removal of Venus from the sun makes sense to observe its phase both in the daytime and at dusk and night, making sketches of every 15-20 minutes. Such observations will allow to study the effect of irradiation.
Sketch of the planet begins with the application of the terminator (the boundary of the illuminated and unilluminated parts of the planet). First, we need try to get right phase and elongation of horns sickle. When bad image it has to be limited. Details on Venus are very blurred and indistinct formations having probably cloudy nature. Dark spots are usually elongated, white – round.
In the figure the dark areas obscured, and the light shall have either a dotted light areas are often issued for the limb and terminator. Observations of such projections represent special interest because they are likely to cloud our type of noctilucent clouds located above the main cloud layer of Venus. From these observations we can determine the height of the upper clouds above lower. In observations with optical filters to evaluate the visibility of light and dark parts and form the terminator when observed with each filter, or make sketches for each filter. Such observations may give an idea of color components. It is recalled that the observation of details on the surface of Venus must be approached with great caution, because very often these details are so weak and vague, that there are doubts in their reality. Therefore, the larger the diameter of the telescope – the better! Pure heaven!