What’s in the Sky – October 2012
Mercury, the solar system’s innermost planet, returned to the evening sky on September 10, after its most recent superior conjunction and will remain an evening object until November 17th. By the second half of October Mercury will be set about 2 hours after the Sun. Mercury starts the month in Virgo then moving through Libra before ending the month in Scorpius. Low in the western evening sky just after sunset at the beginning of October, Mercury begins the month in Virgo just over one degree to the north of Virgo’s brightest star, Spica.
Oct 1st: Mercury and Saturn will be close.
Oct 6th: Mercury and Saturn, both of which are currently in the constellation of Virgo, will be at conjunction after sunset. Mercury will be being the brightest at magnitude -0.3 with Saturn to its right will be at magnitude 0.7. The bright star, Spica will be just below forming the point of a small triangle.
Oct 8th: Mercury at aphelion
Oct 16th: Mercury will be close to Zubenelgenubi the second brightest star in Libra
Oct 17th: Mercury and Zubenelgenubi will be just below the two day old crescent Moon at around 7pm
Oct 26th: Mercury will reach its greatest eastern (evening) elongation from the Sun and will be at its highest point in the sky.
Venus is the ‘morning star’ at present and will remain visible in the morning skies until January 2013. In a telescope, Venus will show about 60% gibbous phase and will have a magnitude of -4.1. Venus will move in to the constellation of Virgo by the 23rd October. It rises about ninety minutes before the Sun at the beginning of the month.
Oct 3rd & 4th: Venus pass less than half of a degree from Leo’s brightest star, Regulus
Oct 12th: Venus, waning crescent Moon and Regulus will form a right angle triangle in the sky
Oct 31st: Venus at perihelion
The red planet can easily be found low in the western evening sky after sunset. Situated among the stars of Libra at the beginning of the month. It crossed into Scorpius on the 7th, passing through the jaws of the Scorpion on the 11th and on into Ophiuchus on the 19th.
Oct 1st: Mars 0.1 degree from minor planet 7 Iris
Oct 18th: 3 day old waxing Moon will be close to Mars
Oct 19th: Mars, the star Antares and the crescent Moon make a temporary triangle in the early evening sky
Oct 22nd Mars will be 3.5 degrees to the north of Antares. The colour resemblance between these two objects can be quite striking, both exhibiting a slightly orange tint with Antares being the slightly brighter of the two. The name Antares actually means “rival of Mars”.
On the night of 5/6 October, the moon is near Jupiter, and occults it as seen from South Western Australia at sunrise, and along Australia’s southern coast in daylight. The giant planet rises just after 11.00pm at the beginning of the month and by the end of the month at around 10pm. Jupiter spends the entire month in Taurus where it is close to the waning gibbous Moon on the 6th. Its four Galilean satellites will appear to the west of the planet on the 11th of the month and to the east of the planet in the early evening on the 21st.
Oct 4th: Jupiter stationary (Midnight)
Oct 5th: Gibbous Moon, the star Aldebaran and Jupiter make a temporary triangle in the morning sky
Oct 6th: Gibbous Moon and Jupiter close in the morning sky.
Saturn starts the month low in the Western sky setting around 7pm. Saturn goes round the far side of the Sun on 25 October, and towards the end of the month, emerges back out into the morning sky. Low in the western evening twilight at the beginning of the month, Saturn is very quickly heading towards its conjunction with the Sun on the 25th. It will be lost from view until it appears in the early morning twilight next month.
Oct 6th: Mercury, Saturn and the star Spica make a temporary triangle low above the Western horizon in the early evening twilight. Difficult and will require a clear horizon.
Oct 16th: Slim crescent Moon located to left of and above Saturn, low above the Western horizon in the evening twilight could be difficult to see.
Oct 25th: Saturn at conjunction 7pm
Uranus is a particularly good target this month particularly after midnight. It should be visible in binoculars.
It rises after sunset and sets before sunrise throughout the month. It is in Pisces this month. You may be able to recognize Uranus just by its hue, which most people find faintly blue or green. I can see the colour even with my 10×50 binoculars. In a dark sky you can pick it naked eye if you have a good finder scope.
Neptune is currently in the constellation of Aquarius, sets after 3am at the start of October and just after 1am at the end of the month. Neptune varies from magnitude 7.8 to 8.0, about two magnitudes fainter than Uranus. It’s visible in steadily supported binoculars, but only if you look quite carefully. The planet disk can be resolved in a 4inch (100mm) aperture telescope but only in really good conditions. In a 6 inch the disk can be plainly visible.