SKYWATCH – JULY
APHELION
Despite being in our summer period, Earth is at its furthest point from the Sun on the 6th July. Its orbit is elliptical and with elliptical orbits the closest point is also the narrowest, and fastest. Earth’s present position is at the broader end, where it goes more slowly. (This is why the Northern Hemisphere has a slightly longer summer than the Southern Hemisphere.)
PLANETS
At the beginning of the month at dusk there are four planets lined up in the western sky. Closest to the horizon is Mercury, in amongst the stars of Gemini. (Mercury should be observed after the Sun sets, because its orbit is so close; and it is visible only in places with a low horizon.) Following it westward are Venus, Mars and Saturn, all in or near the constellation of Leo (before, under and behind it, respectively). As the month progresses, they leave Leo behind - Mars moves next to Saturn in Virgo, and Venus creeps towards them both. They are all followed during the night by the distant planets, Neptune and Uranus.
CONSTELLATIONS
To the left/east of Virgo is the small constellation of Libra, and to its left is Scorpius. Libra was originally seen as claws of the scorpion, but in Roman days it changed to scales held by Virgo, the Goddess of Justice. None of its stars are brighter than the Plough’s, but it contains a number of double and multiple stars which can be split using binoculars or a telescope.
Ophiuchus, a far bigger constellation, nudges a foot in between Libra and Scorpius, thus laying claim to be the ‘thirteenth’ constellation in the Zodiac band. It represents the Greek God of Medicine, Asclepius, holding a serpent - a symbol of healing still used today. Like Libra, none of its stars is exceptionally bright, but it also repays observation with some magnification. There are several globular clusters – very old, tightly knit families of stars; and a few open clusters – much younger stars, loosely held by gravity and slowly moving away from each other; with some good coloured and double stars as well.
SKYWATCH – JULY
APHELION
Despite being in our summer period, Earth is at its furthest point from the Sun on the 6th July. Its orbit is elliptical and with elliptical orbits the closest point is also the narrowest, and fastest. Earth’s present position is at the broader end, where it goes more slowly. (This is why the Northern Hemisphere has a slightly longer summer than the Southern Hemisphere.)
PLANETS
At the beginning of the month at dusk there are four planets lined up in the western sky. Closest to the horizon is Mercury, in amongst the stars of Gemini. (Mercury should be observed after the Sun sets, because its orbit is so close; and it is visible only in places with a low horizon.) Following it westward are Venus, Mars and Saturn, all in or near the constellation of Leo (before, under and behind it, respectively). As the month progresses, they leave Leo behind - Mars moves next to Saturn in Virgo, and Venus creeps towards them both. They are all followed during the night by the distant planets, Neptune and Uranus.
CONSTELLATIONS
To the left/east of Virgo is the small constellation of Libra, and to its left is Scorpius. Libra was originally seen as claws of the scorpion, but in Roman days it changed to scales held by Virgo, the Goddess of Justice. None of its stars are brighter than the Plough’s, but it contains a number of double and multiple stars which can be split using binoculars or a telescope.
