VENUS, the dazzling morning or evening star, outshines all the other stars and planets
in the night sky.
From the beginning of 2012, Venus is brilliant in the west as the Evening Star, reaching greatest western
elongation on 27th March. It disappears from view by the end of May,
to re-emerge as the Morning Star in mid-June. Venus is then visible before dawn until the end of the year.
January: Venus commences 2012 as a brilliant evening object, brightening from -4.0 to -4.1 magnitude during January whilst moving from
Capricorn into Aquarius. The planet can be seen in the
south-western sky after dusk, setting 3 hours after the Sun in northern temperate latitudes. During January the planetīs
phase decreases from 83% to 74%. On January 26th
the waxing crescent Moon passes close to Venus, creating an attractive spectacle in the evening twilight sky.
February: From northern temperate latitudes, Venus sets almost 4 hours after the Sun. From tropical and more southerly latitudes
the planet sets just 2 hours following the Sun. Venus moves into Pisces during February and brightens
slightly to -4.2 magnitude. The planet appears gibbous as its phase decreasing from 74% to 64%.
March: Venus reaches greatest elongation on the 27th March and is a spectacular object in the evening sky. During March brightness
increases from -2.2 to .4.4 magnitude, the phase decreases from 64% to 49% and the planet moves
rapidly from Pisces, through Aries and into
Taurus. At greatest elongation on March 27th,
Venus sets 4 hours 40 minutes after the Sun. Moonless evenings just after mid-month are an ideal time to check for shadows cast by Venus.
The planetīs easterly motion through Aries takes it past Jupiter between the 12th and 15th March, making a fabulous pairing of two bright
planets. On the 25th and 26th March the waxing crescent Moon is closeby.
April: Remaining a spectacular evening object, Venus still sets 4 1/2 hours after the Sun in northern temperate latitudes. Brightness
increases slightly to -4.5 magnitude during April and the phase decreases further to 27%. Through
a small telescope, you can observe the planetīs shape change from half-illuminated to a crescent as Venus approaches Earth. Moving against the
background constellation of Taurus, Venus appears very close to the
Seven Sisters (Pleiades) on the 2nd and 3rd April presenting an interesting photo
May: Venus begins the month as a prominent object, -4.5 magnitude in the south-western evening sky, setting 4 hours after the Sun
in northern temperate latitudes and just 2 hours after in the tropics and more southerly climes. However, Venus moves very rapidly towards
the Sun as May progresses and will be lost in the bright dusk twilight sky before the end of the month.
June: Venus passes through inferior conjunction on 5th - 6th June when it
can be seen in a rare transit across the face of the Sun. The next transit isnīt until
2117! At this time Venus is too close to the Sun to be seen in the sky but it reappears in the north-easterly morning sky on 15th
June shortly before sunrise for observors in equatorial and southerly latitudes. From these latitudes, by the end of June, Venus rises
2 hours before the Sun increasing from -4.0 to -4.4 magnitude with a phase increasing to 16%.
Venus is too low for good observation in northern temperate latitudes.
July: Venus is still low in the morning sky for northerly observors but, as the month progresses, it draws away from the Sun and, by
the end of July, rises 3 hours before the Sun with a phase increasing to 41%. Closeby Jupiter
moves away as the month proceeds and, as the eastwards motion of Venus is faster than that of Jupiter, they are well separated by the end of July.
The crescent Moon makes an interesting grouping with Venus, Jupiter and the star Aldebaran (magnitude +0.85) in
Taurus on the morning of 15th July.
August: Venus passes through greatest western elongation in mid-August and, whilst still a brilliant morning object, fades slightly
to -4.2 magnitude. By the end of August, Venus rises 4 hours before the Sun from northern temperate latitudes, with a
phase increasing to 58%. The rapidly moving planet moves from
Taurus into Gemini during the month. The waning crescent
Moon is close to Venus on the morning of 14th August.
September: Continuing to rise 4 hours before the Sun, during September brightness fades slightly to -4.1 whilst the
phase increases to 70%. Moving eastwards, Venus moves from
Gemini, through Cancer and into
Leo. The waning crescent Moon appears close to Venus on the morning of 12th September. On
13th September Venus is just below The Beehive (Praesepe) star cluster
October: Fading slightly to -4.0 magnitude during October, Venus rises 3 1/2 hours before the Sun and remains a lovely morning object
as it moves into Virgo during the month with a phase
increasing to 81%. The waning crescent Moon lies close to the right of Venus on 12th October and on 13th October is directly below
November: Remaining at -4.0 magnitude during November, Venus rises less than 3 hours before the Sun by the end of the month and
considerably less from the tropics and southerly climes. During November, Venus moves into Libra
with a phase increasing to 88%. The waning crescent Moon lies close to Venus on 11th
November and on 27th November Venus passes 1š south of Saturn.
December: By the end of 2012, Venus, at -4.0 magnitude, rises just 1 1/2 hours before the Sun from all latitudes as its
elongation from the Sun decreases. The planetīs phase
increases to 94%. Venus is close to the much fainter Mercury during the first two weeks of December. If youīre up before dawn on 11th December
look to the south-east for a beautiful grouping of Venus with the crescent Moon, Mercury to the lower left and Saturn higher up to the right.
||Greatest Elongation East - 46š - mag -4.4|
|June 05 to 06
|June 05 to 06
||Transit of Venus across the face of the Sun|
||Greatest Elongation West - 46š - mag -4.4|
MARS, the Red Planet, brightens during January and February until reaching its bi-annual
opposition on 3rd March. Thereafter, it starts to fade until lost from view in October.
It re-emerges from the Sunīs glare at the end of November, low in the south-west in the early evening.
January: Mars commences 2012 moving eastwards with a direct motion in Leo, crossing into
Virgo mid-month. The planet reaches its first stationary point on 24th January and thereafter moves
retrograde westwards, back towards the border with Leo. It rises mid-evening by the end of January with a brightness increasing from +0.2
to -0.5 magnitude.
February: Mars rises mid-evening at the beginning of the month and 2 1/2 hours earlier at the end, noticably brightening from -0.6 to -1.2.
Its retrograde motion carries it back into Leo in early February. Mars passes aphelion on 15th February
when it lies 249.2 million kilometres, its greatest distance, from the Sun.
Mars is in opposition on 3rd March with a magnitude of -1.2 and is visible all night. It ill be
at its closest to Earth two days later, at 100.8 million kilometres. As this is an aphelic opposition (see diagram on the left), the apparent diameter
of the disk reaches just 13.9 arc seconds at opposition this year - about half the apparent disk diameter enjoyed at a perihelic opposition when, as in
August 2003 when it was only 56 million kilometres from Earth, it can attain 25.1 arc seconds. Mars will not be as close as in 2003 again until 2018.
Opposition in 2012 occurs close to the northern hemisphere summer/southern hemisphere winter solstice on Mars, which takes place on 30th March,
so that the north pole of the planet will be tilted towards Earth. At opposition, a small telescope will show the polar cap, dark rocky outcrops and other
major markings on the planetīs surface. Mars fades quickly after opposition as the apparent size of the disk decreases whilst its distance from Earth
increases. By the end of March, magnitude will be -0.7 and the disk diameter 12.6 arc seconds.
April: Now past opposition, but still visibe all night, Mars fades to 0.0 magnitude during April and the apparent diameter of the disk drops to
10 arc seconds. The planet commences April moving retrograde in Leo but, after reaching its second stationary point
on 14th April, recommences a direct easterly motion.
May: Continuing to traverse Leo, Mars fades further to +0.5 magnitude during May as its distance from
Earth increases. It is visible in the southern sky as night falls and sets in the early hours of the morning.
June: Visible in the south-western sky as darkness falls and setting close to midnight, Mars moves into Virgo
on 21st June and fades to +0.8 during the month.
July: Mars, still visible as darkness falls and setting before midnight, is moving through Virgo
west of Saturn (also in Virgo and slightly brighter). Magnitude fades to +1.1 by the end of July as Earth pulls away from slower-moving Mars.
August: Mars is visible in the early evening, low in the west-south-western sky, but sets less than two hours after the Sun. Its rapid easterly motion
takes Mars past Saturn, both in Virgo in mid-Agust. On the evening of 14th August, Saturn, Mars and Virgoīs star Spica (no 1 on our
Virgo chart) will all be in line and it will be interesting to compare the brightness and colours of the three objects
- Saturn +0.8 magnitude should look yellow, Mars +1.1 magnitude and reddish, and Spica approximately +1.0 magnitude and blue-white. From northern temperate
latitudes Mars is low in the twilight dusk by the end of August but better placed for observors situated further south.
September: At magnitude +1.2 , Mars continues to be visible in early evening in the south-western sky as it moves from
Virgo into Libra during the month. From northern temperate latitudes, the
planet remains low in the twilight at dusk setting less than two hours after the Sun but is better placed for observors further south.
October: Mars is too low in the south-western dusk to be easily observed from northern latitudes. The waxing crescent Moon appears closeby on
18th October and the planetīs motion carries it from Libra, through Scorpio
and into Ophiuchus during the month. Observors in the tropics and southern hemisphere can see Mars pass north of
the red star Antares (no 10 on our Scorpio chart) on 22nd October, presenting an interesting opportunity to
compare colour and brightness - Mars at +1.2 magnitude and Antares slightly brighter at +1.05 magnitude.
November: Although very low for northern observors, darker skies at the end of November mean Mars may become visible again, for a short window after
sunset, as it continues to be from further south. Magnitude remains at +1.2 whilst the planet moves from Ophiuchus
into Sagittarius during November. The waxing crescent Moon passes above Mars on 16th November.
December: Still low in the sky, at magnitude +1.2, Mars moves from Sagittarius to see the year out in
Capricorn. The crescent Moon lies above on 15th December.
||1st Stationary Point - Virgo - mag -0.5|
||Opposition - Leo - mag -1.2|
||Closest to the Earth - 100.8 million kilometres|
||2nd Stationary Point - Leo - mag -0.4|
JUPITER lies in Aries at the beginning of 2012, gradually fading until,
by the end of April, it has disappeared into the Sunīs glare. It reappears in the north-east in June against the constellation of
Taurus near the Pleiades (Seven Sisters). In the early
morning of 15th July, Jupiter is occulted by the Moon. Brightening through the summer months,
Jupiter reaches opposition on 3rd December.
||Conjunction - Aries|
||1st Stationary Point - Taurus - mag -2.6|
||Opposition - Taurus - mag -2.8|
SATURN is at its best for observing from January to August, reaching
opposition on 15th April. by early September it has sunk into the twilight glow but
re-emerges as a morning object in mid-November. After spending most of the year in Virgo,
Saturn moves into Libra during December.
||1st Stationary Point - Virgo - mag +0.5|
||Opposition - Virgo - mag +0.3|
||2nd Stationary Point - Virgo - mag +0.6|
||Conjunction - Virgo|
URANUS start the year just visible to the naked eye but by March it has
disappeared into the twilight glow. It reappears in June with visibility improving into the autumn. Uranus spends another year in
Pisces and reaches opposition
on 29th September.
||Opposition - Pisces - mag +5.7|
NEPTUNE spends another year in Aquarius and is best
viewed from May onwards. It reaches opposition on 24th August.
||Opposition - Aquarius - mag +7.8|