Drawing the bedroom curtains at 7am this morning Venus was un-missable, gleaming in the south east sky like the headlight of some UFO. Lying above and to the right of the un-risen Sun she is presently the ‘Morning Star’ but her dazzling beauty in the dark blue, pre-dawn sky is soon engulfed by the light from the rising Sun. She is still up there of course, moving westwards to set invisibly before the sun chases her down below the western horizon. Venus is the second brightest object in the night sky after the Moon. She can cast shadows and can, rarely, be visible in broad daylight.
Mercury and Venus are inferior planets, closer to the sun than we are, lying within the Earth’s orbit, and therefore they never appear in the middle of the night when our bit of the Earth, with us on it, faces away from the Sun and the two inner, inferior, planets. Observed from Earth Venus is never more than 47° (maximum elongation) away from the Sun and therefore appears to follow our star around. Galileo first observed that Venus showed ‘phases’ like those of the Moon; cycling in appearance from a crescent to a half-disc, to full disc and back again. This proved to him that Venus orbited the Sun, not the Earth, and got him into a lot of trouble with the Vatican. Venus is at her brightest at maximum elongation from the sun when she is a half-disc.
As Venus continues her (Venusian) year’s journey around the Sun from where she is at present she will eventually appear to the left, the east side, of the Sun and become instead the ‘Evening Star’. Venus moves more rapidly around the Sun than we do and she will then overtake us to become the Morning Star once again.
The Greeks did not realise that these two phenomena reflected the same heavenly body so they called the Morning Star Phosphorus and the Evening Star Hesperus (see under Henry W Longfellow’s Wreck of the Hesperus and Groucho Marx’s Lydia the Tattooed Lady). The Romans did realise this ‘star’ was one object but retained the temporal differentiation as Lucifer (the light-bringer) in the morning, and Vesper in the evening.
Venus is almost exactly the same size as Earth and is one of the four rocky ‘terrestrial” planets. She rotates very slowly in the opposite direction from Earth, so slowly in fact that a Venusian day is longer than a Venusian year. Her dense atmosphere is 96% CO2 and with a mean temperature of 464°C she is the hottest planet in the Solar System. She presents a featureless, dazzling surface to the Earth. Even with a good telescope the surface is disappointingly devoid of detail. Also, she has no moons – while Jupiter has several and Saturn has jaw-dropping rings that were created when one of its moons disintegrated. These latter two monster ‘superior planets’ are farther away from the Sun than we are, outside Earth’s orbit, which means they can be visible in the darkest part of the night. At the moment the two gas giants are close together in the early night sky.
To the naked eye the most obvious heavenly bodies are the Sun and Moon and the planets Mercury, Venus, Mars, Jupiter and Saturn. The total, seven, was a significant number to the Romans, to whom the planets also represented the gods. Originally the days of the week were named after the god-planets: dies Solis (Sunday) dies Lunae (Monday), dies Martis (Tuesday), dies Mercurii (Wednesday) dies Iovis (Thursday), dies Veneris (Friday) and dies Saturni (Saturday).
Living in the pagan north, some of our days were renamed in honour of the Norse gods, giving us Tiw’s day, Woden’s day, Thor’s day and Freya’s day. The French stuck with Imperial Rome and used mardi, mercredi, jeudi and vendredi for Tuesday to Friday. The romance languages use some version of sabbath (shabbat) for Saturday and ‘The Lord’s Day’ for Sunday, giving us sabato and domenica in Italian and sabado and domingo in Spanish. The now slightly disgraced tenor Placido Domingo’s name means ‘peaceful Sunday’.
Although all the planets lie broadly on the ecliptic (the plane of Earth’s orbit around the Sun) Venus’ orbit is slightly inclined compared to the Earth which means she does not always pass exactly between us and the Sun. When she does, this is called a transit of Venus and allows astronomical measurements to be calibrated, so that things like the size of the Solar System can be calculated. Captain Cook sailed to Tahiti in 1768 to observe a transit of Venus, then went on to explore the east coast of Australia. Exoplanets outside our solar system can be sought by measuring the slight decrease in luminosity of distant stars as a transit occurs.
https://en.wikipedia.org/wiki/2012_transit_of_Venus
The astrological sign for Venus is a circle surmounting a cross. It is also the symbol for female – a concept that has become controversial recently. As well as being the most striking planet, Venus is of course the Roman goddess of beauty, love and desire, the equivalent of the Greeks’ Aphrodite – and the diseases of love are named after her.
The Bohemian Waxwing 