|Events during February
|7th - MERCURY in superior conjunction
19th - NEPTUNE in conjunction with the Sun
MOON: Full - 7th, New - 21st, Perigee - 367,920 kilometres - 11th, Apogee - 404,860 kilometres - 27th.
3rd - Moon occults the Crab Nebula.
A fascinating experience through a moderate telescope when you can see the dark edge of the Moon begin to hide the supernova remnant just after 7pm and obscure
it for 45 minutes.
8th - Moon passes below Regulus, the brightest star in Leo.
9th/10th - Moon passes below Mars.
12th/13th - Moon lies below Saturn, with Spica (the brightest star in Virgo) to the Moonīs upper right.
15th - before dawn, the last quarter Moon is near Antares (a red supergiant in Scorpio).
25th - dusk sees the crescent Moon very close to Venus with Jupiter above - a beautiful sight.
26th - the Moon lies near Jupiter with a brilliant Venus below.
Mercury is in superior conjunction
on 7th February and so will not be visible for the first two weeks of the month. By the end of the third week of February, the planet will have moved far enough east
to become visible in the western sky in the evenings for observors in tropical and northern latitudes. This is the most favourable evening apparition of 2012
for the northern hemisphere.
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.
Venus is a brilliant object in the south-western sky at dusk and throughout the early evening. From
northern temperate latitudes, the planet sets nearly fours after the Sun by the end of February but from tropical and more southerly latitudes it sets just two hours
after the Sun.
Venus is in Aquarius at the beginning of February but moves into neighbouring
Pisces during the month, brightening slightly from magnitude -4.1 to -4.2. The planet shows a gibbous
phase, decreasing from 74% to 64% during the month.
On February 25th, the waxing crescent Moon appears close to Venus and the following night is between Venus and Jupiter.
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.
Mars rises in mid-evening with a magnitude noticably brightening from-0.6 to -1.2
during February as it heads towards opposition in March. The planetīs retrograde motion carries it back from
Virgo into Leo early in February.
Mars passes aphelion on 15th February, when it will be 249.2 million kilometres,
its greatest distance from the Sun.
Mars will be at opposition on March 3rd 2012 in Leo. Two days later, on March 5th, the planet will have its closest approach to Earth during
this apparition - 100.78 million kilometres. Mars will be considerably close to the aphelion of its orbit, which it will have just passed on February 15th 2012.
This opposition occurs close to the northern Summer/southern Winter Solstice on Mars, which takes place on March 30th 2012, so that Earth will be at high
northern declination from Mars, and the Martian North Pole will be in good view from Earth.
This opposition provides an opportunity to send further spacecraft to Mars. NASA is sending its Mars lander-rover mission, the Mars
Science Laboratory (MSL, which is also named Curiosity), launched in November 2011. The rover is the size of a Mini-Cooper and is intended
to perform a 2 year science mission on the surface of Mars. This is a sophisticated mission for advanced studies on the Martian surface, including new
technologies - the long-range, long-duration rover, powered by a small nuclear reactor, is equipped to perform many scientific studies of Mars including
the geology, composition and life-potential of the Red Planet, and to demonstrate the technology for accurate landing and hazard avoidance in order to travel to
difficult-to-reach sites. For the first time NASA has admitted the project was designed to look at possibilities of humans going to Mars.
The Russian Space Agency delayed its Phobos-Grunt mission from 2009/2010 to this apparition and is an attempt to return samples from Mars' moon Phobos.
It was launched carrying the Chinese Mars Orbiter Ying Huo 1 on November 8th 2011.
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.
Jupiter can be seen in the southern sky as soon as darkness falls, but it now sets around midnight.
The planet is moving drectly in Aries, fading slightly from magnitude -2.4 to -2.2 during February, as its distance
from Earth increases. The waxing crescent Moon is closeby on 26th February.
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.
Saturn now rises before midnight, brightening slightly from magnitude +0.6 to +0.4 during February.
The planet reaches its first stationary point on 8th February and thereafter follows a retrograde path,
remaining in Virgo.
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.
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.
Neptune is in conjunction with the Sun
on 19th February and therefore not observable during this month.
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.
No longer an offical planet and never brighter than +13 magnitude, Pluto is only visible through powerful telescopes.
Full moon: 7th
Last quarter: 14th
New moon: 21st