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Events during January
3rd/4th - Quadrantid meteor shower at its best. Best to look in the early hours of the morning after the
Moon has set.
5th - EARTH is at perihelion, its closest to the Sun (147 million kilometres / 91.3 million miles).
MOON: Full - 9th, New - 23rd, Apogee - 404,580 kilometres - 2nd and 404,325 - 30th,
Perigee - 369,880 kilometres - 17th.
2nd - Moon close to Jupiter
13th/14th - Moon near to Mars
16th - in the morning, the last quarter Moon passes below Spica with Saturn to the upper left
17th - in the morning, the Moon is below Saturn
19th - the waning crescent Moon rises above Antares
26th - the waxing crescent Moon forms a pretty pairing with Venus after sunset
29th and 30th - Moon near to Jupiter
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Mercury
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From northern temperate latitudes during early January, Mercury, at -0.4 magnitude, is visible as a
morning object low above the south-eastern horizon before sunrise. From equatorial and more southerly latitudes the planet is visible in the east-south-east until
the middle of January.
The best times to observe Mercury in the northen hemisphere are when it is an evening star in the spring and a morning star in the autumn. In midsummer
the lighter skies make visibility difficult near the horizon.
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Venus
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Venus is a brilliant -4.1 magnitude, queen of the evening sky in a reign that will last until May.
From northern temperate latitudes Venus is seen in the south-western sky at dusk setting more than three hours after the Sun by the middle of January. From the
tropics and the southern hemisphere the planet sets about two hours after the Sun.
Venus is in Capricorn at the beginning of 2012 and moves into
Aquarius during January. Approaching inferior conjunction
in June this year, during January Venusī phase decreases from 83% to 74%.
On January 26th the waxing crescent Moon passes close to Venus making an attractive spectacle in the evening twilight sky.
On the 8th June 2004, Venus was at inferior conjunction
and transited the sun. Transits of Venus are rare, taking place at greater
than 100 year intervals and usually in pairs. The last two transits of Venus were in 1874 and 1882. 2004's transit lasted 6 hours, the total event
visible from Europe as a small black disc crossing the lower part of the Sun from left to right. The next transit will be on 5th June 2012.
After that, transits of Venus won't occur again until 2117 and 2125.
Before and after inferior conjuction, when Venus is
the closest it comes to the Earth, are the times at which the planet is most brilliant and can be seen setting or rising
4 hours after or before the Sun.
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Mars
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Mars rises in mid-evening by the end of January. Heading toward oppostion in
March 2012, Mars brightens considerably from +0.2 to-0.5 magnitude during the month. The planet commences 2012 in
Leo with a direct motion, moves into Virgo mid-month,
reaches its first stationary point on January 24th, then begins a retrograde motion back into Leo.
At opposition on the 28th August 2003, Mars was only 56 million kilometres from the Earth. It showed a
disc of 25.1 seconds of arc across which is almost as large as it can ever appear. Mars started 2003 at 310 million kilometres from
the earth at 4.5 seconds of arc and 1.6 magnitude. By opposition it brightened 50 times to reach -2.9 magnitude but faded to 0
magnitude by December. Even to the naked eye Mars was a striking object in the summer and autumn sky, easily identifiable by its
reddish hue in an area of sky poor in bright stars. Mars will not be as close again until 2018.
These favourable oppositions occur every 15 or 17 years but other oppositions occur at average intervals of 2 years 2 months during
which time the planet makes a complete circle of the Earth. In general Mars is observable every other year, being too close to the sun for favourable conditions
during other times. Brightness at opposition varies from -1.0 to -2.9 magnitude, and when furthest from the earth it fades to 1.7 magnitude. The planet can be
identified by its orange-red colour.
As in 2003, Mars comes nearest to the Earth at oppositions at the end of August. At these times it can be brighter than Jupiter,
although low in the sky in Aquarius for northern observors. In the northern hemisphere, the planet may be better seen at oppostions during autumn and winter months
when it is higher in the sky.
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Jupiter
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Jupiter remans a splendid object visible in the southern sky as soon as darkness falls and setting
in the early morning hours. Jupiter begins the month in Pisces, then moves into neighbouring
Aries.
During January, magnitude fades from -2.6 to -2.4 as the distance from Earth increases. The waxing first-quarter Moon will appear close to Jupiter in the sky on
January 2nd and 30th.
After spending the past six years in the southern skies, Jupiter moved north of the celestial equator on February 5th 2011 to spend the next six years
in northern skies.
Varying from 603 (at its closest) to 770 million kilometres from the sun, the difference in brightness between opposition and conjunction varies less than
with Mars, from about -2.9 to -1.8 magnitude. Always a bright planet, Jupiter comes to opposition a month later each year, moving approximately from one zodiacal
constellation to the next.
The 4 largest of Jupiterīs 60+ moons are easily visible through binoculars or a small telescope, ranging from 4.6 to 5.6 in magnitude. The innermost,
Io, takes 1.8 days to orbit the planet making its motion easily detectable within a few minutes.
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Saturn
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Saturn rises in the early morning hours, brightening slightly from +0.7 to +0.6 magnitude
during January and moving directly in Virgo.
Following the ring plane crossing in September 2009, the tilt of the rings has now opened to an angle of 14.2š as viewed from Earth, making the planet
once again a lovely sight through a small telescope.
Saturn moves more slowly than Jupiter and can remain in the same constellation for several years. The brightness of the planet depends on the
aspect of its rings, as well as its distance from Earth and the Sun.
The planet crossed the equator into the northern hemisphere in 1996 where it remained until 2010 with the southern side of the ring system
facing Earth. Because of its distance, its brightness varies little between opposition and conjunction but is affected by the huge ring system. Seen edge on the
rings contribute little or no light.
Every 15 years the plane of Saturn's rings passes through the Sun, illuminating first the north and then the south side. For a few days the
rings are edge on to the Sun. About the same time the Earth passes through the ring plane and, depending on the Earth's position, this may happen just once or 3 times.
During 1995/96 there was a triple crossing and the next will be 2038/39. The last single crossing was in 2009 and the next will be in 2025.
Saturn's largest moon, Titan, is visible in small telescopes orbiting outside of the ring system.
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Uranus
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Uranus remains in Pisces with a magnitude of +5.7. Although
barely visible to the naked eye, it is easily located with binoculars.
Brightness varies only slightly, reaching a maximum of +5.6 magnitude at opposition. Although this is bright enough to see with the naked eye, identifying it against
the stars can be difficult. At closest approach, Uranus is 2,856 million kilometres (1,775 million miles) from Earth.
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Neptune
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Neptune is a morning object in Aquarius,
visible in binoculars or a small telescope.
At just over a degree from Venus, setting around 18:30h, Neptune can be located above Venus on the 12th January and to the upper right of Venus on the 13th.
Neptune has an average magnitude of 7.9 which varies little with changing distance. At its closest,
Neptune is 4,341 million kilometres (2,697 million miles) from Earth. |
Pluto
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No longer an offical planet and never brighter than +13 magnitude, Pluto is only visible through powerful telescopes.
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Moon
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January:
First quarter: 1st and 31st
Full moon: 9th
Last quarter: 16th
New moon: 23rd
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