Mean distance from the Sun | 108.2 millions Km (67.2 millions of miles) |
Revolution period | 224,701 days |
Rotational period | 243,16 days |
Diameter | 12180 Km (7568 miles) |
Mass (Earth=1) | 0.815 |
Volume (Earth=1) | 0.860 |
Gravity (Earth=1) | 0.903 |
Number of satellites | 0 |
Mean temperature | +480 °C at soil, -33 °C at top of clouds. |
Minimum distance from the Earth | 40 millions Km (24.8 millions of miles) |
Maximum distance from the Earth | 260 millions Km (161.5 millions of miles) |
Generalities: it is the planet
that appears brighter in the terrestrial sky, the first star for brightness,
after the Sun and the Moon.It is moreover the planet that is next to the
Earth , reaching a least distance of about 40 million Km, about every
17 months.
Venus is an internal planet, which is next to the
Sun, in comparison to the Earth and this enables it to be observable at
most for few hours after sunset or before dawn.
Characteristics: it is a
rocky planet of dimensions very similar to those of the Earth. Its atmosphere
is extremely dense and on the ground an atmospheric pressure approximately
90 times superior to the terrestrial one is reached. The atmosphere on
Venus is for the greatest part composed by carbonic anidride and this enables
the greenhouse effect to be extreme; for this reason on the surface of
Venus the middle temperature reaches 480 Celsius degrees.
Among the other components of the atmosphere of Venus
compounds of sulphur are found, and particularly on this planet even
rains of sulphuric sour take place.
From Venus surface the Sun is never visible
, since the dense atmosphere enables Venus to be always covered with a
dense blanket of clouds.
All these characteristics make Venus one of the most
inhospitable places of the Solar System and therefore surely unsuitable
to the development of any form of life.
The motion of rotation around itself of the planet
Venus has two priorities. The former concerns slowness: the day on Venus
is longer than the corresponding year. The latter concerns the direction:
Venus moves of retrograde motion, that is contrary to that of the other
planets, this means that on Venus the Sun rises west, getting down
east.
Observation: Venus is unmistakable
for its sparkling in the terrestrial sky (its magnitude varies
from -3.9 to -4.7). It is possible to observe this planet at most
for some hours after sunset, in the western sky, or before
dawn in the oriental sky. Its angular distance from the Sun never overcomes
46°.
Peculiarity of internal planets (Venus and Mercury)
is that to introduce the phases, or to show us different portions illuminated
of their disk (as it happens for the Moon). Obviously the phases of Venus
can be recognized only through a telescope, also of modest power. With
a naked eye Venus always appears as a very bright star. This great brightness
is owed to the fact that the thick cloudy blanket that surrounds the planet
reflects a notable fraction of solar light.
Mercury Mars
Jupiter Saturn
Uranus Neptune
Pluto
-
Visibility
of planets during this month