|Events during March
The Moon: Full – 3rd, Last quarter – 12th, New moon – 19th, First quarter – 25th.
The spring equinox, when the Sun crosses the equator into the northern hemisphere, is on the 21st.
There is a total eclipse of the Moon on the 3rd, visible from Europe, the British Isles, Africa and western Asia. The eclipse begins on the 3rd
at 20.16GMT, enters the umbra at 21.30GMT, and begins totality at 22.44GMT. Mid-eclipse is at 23.21GMT, totality ends at 23.58GMT and the Moon leaves
the umbra at 1.12GMT with the eclipse ending at 2.25GMT on the 4th. During this eclipse the Moon passes just to the north of the centre of Earth´s
shadow. During totality, the spring constellations will be well placed for viewing and a number of bright stars will be visible. Spica is 40º
southeast of the eclipsed Moon and Arcturus 49º to the northeast. Saturn will shine at magnitude 0.2 about 24º northwest of the Moon near the western
border of Leo.
A partial eclipse of the Sun takes place on the 19th, visible from Asia and the Arctic Ocean.
This snapshot shows Venus setting in the west, followed by the 2 day old Moon, at 21.00h on 21st March.
The deep sky objects shown in this month´s snapshot are:
M33 – a spiral galaxy in Triangulum at 5.7 magnitude. Under very good conditions the Triangulum galaxy can be seen with the
naked eye. Except for a few people with extremely good sight, at 3 million light years distance, this is the furthest object visible to the naked
eye. It is outstanding in good binoculars, but as its considerable total brightness is distributed quite evenly over an area of nearly four time
that covered by the full Moon, its surface brightness is extremely low. Therefore, it is difficult to view this galaxy in telescopes which do not
allow low magnification.
M34 – an open cluster in Perseus at 5.5 magnitude. This cluster lies about 1,400 light years distance, has about 100 stars and
is estimated to be about 180 million years old. It can be resolved into stars by 10x50 binoculars and is best at low magnification in telescopes.
M45 (the Pleiades or Seven Sisters) - an open cluster in Taurus at 1.6 magnitude with a reflection nebula extending some
M78 – a diffuse reflection nebula in Orion at 8.3 magnitude. Just visible in binoculars under good conditions as a dim patch
resembling a comet. Small telescopes show a remarkably bright area with two stars, akin to a double nucleus in a comet head.
||Mercury is in the morning sky at greatest western elongation of 28º on the 22nd. Being south of the
Sun it is not observable.
The best times to observe Mercury 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 moves from Pisces into Aries and remains at –4.0 magnitude. It sets about 23.00h by the end of
March with the Moon above on the 21st.
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. June's transit
began at 7.20h and lasted 6 hours until 13.20h, 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 in late 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. The dates of the next two inferior conjunctions are October 28th 2010 and October 26th 2018.
||Mars is at 1.1 magnitude in Capricorn and remains low in morning twilight until June. It rises about
5.30h by the end of the month with the Moon below on the 16th.
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 for another 15 years.
These favourable oppositions occur every 15 years but other oppositions occur at average intervals of 2 years 2 months. 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.
||Jupiter in Ophiuchus at –2.2 magnitude, rises about 2.00h by the end of March with the Moon below on
Being 770 million kilometres from the sun, the difference in brightness between opposition and conjunction varies less than with Mars, from about -2.8 to -1.8 magnitude.
The 4 largest moons of Jupiter are easily visible through 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 is in Leo at 0.0 magnitude, at opposition on the 10th and above the horizon all night. The full
Moon is closeby on the 2nd.
Saturn crossed the equator into the northern hemisphere in 1996 where it will remain until 2010 with the southern side of the ring system facing the 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 next single crossings will be in 2009 and 2025.
Saturn's largest moon, Titan, is visible in small telescopes orbiting outside of the ring system.
||Uranus in Aquarius, is in conjunction with the Sun on the 5th and not visible this month.
Brightness varies slightly reaching 5.6 magnitude at opposition. This is bright enough to see with the naked eye but identifying it against the stars is difficult.
||Neptune in Capricorn, rises about 5.00h by the 31st.
Neptune has an average magnitude of 7.9 which varies little with changing distance.
||Never brighter than 13 magnitude, Pluto is only visible through powerful telescopes and we will therefore not be reporting on its position in the sky.|
Full moon: 3rd
Last quarter: 12th
New moon: 19th
First quarter: 25th
The Moon in 2007:
The Moon was seen unusually high and low in the sky during 2006 (see Moon). Although the extremities occurred last year, the Moon will still be seen very
high and very low each month this year, most noticeable around full Moon. It will be near full and high around the 2nd and 29th January, the 25th February
and the 24th March; and near full and low around the 1st and 28th June.
During each month of 2007, the Moon will pass through the Pleiades. This will mostly be in daylight but observable 01.00-04.00h 7th August,
0.00-03.00h 28th October and 22.00-01.00h on the 21st to 22nd December. Binoculars will give a clearer view.