During January the Earth is at perihelion on the 2nd - 147 million kilometres from
the sun - the closest it comes, the Quadrantids Meteor Shower is from the 2nd-4th, Saturn is at opposition on the 13th and
the full Moon is on the 25th.
The Quandrantids Meteor Shower
The Quadrantids meteor shower lasts from the 28th December to the 7th January with maximum meteors on the 3rd January.
Visibility is good this year with only a quarter moon on this day. Predictions are for an average rate of between 50 and
200 meteors per hour at peak time. This is one of the year's most intense meteor showers.
The Quadrantids radiate low in the northern sky from close to the constellation of Bootes, near the tail of The Plough,
but get their name from an ancient constellation called Quadrans Muralis. This shower is rich in faint meteors of moderate
||Mercury is at -0.3 magnitude at the beginning of January visible low in the
southeast morning twilight until the 10th. Mercury becomes visible again as an evening object from the 14th February. Venus
is closeby but much brighter. The moon is to the south on the 9th.
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, at -3.9 magnitude, continues to move closer to the sun and can be seen in
the southeast twilight close to Mercury. The two planets together for so long is an unusual and magnificent spectacle for
early morning risers to observe. The moon is to the south on the 9th.
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.
||At 1.5 magnitude, Mars passes from Scorpio to Ophiuchus during January. The moon
is closeby on the 7th.
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 remains in Virgo throughout 2005. During January the planet is at -2.2
magnitude increasing to a maximum brightness of -2.5 in March and then fading to finish the year at -1.8 magnitude in
December. The moon is closeby on the 3rd and 31st.
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 Gemini until late June when it moves into Cancer for the
remainder of 2005. Currently at -0.4 magnitude the planet will fade to 0.4 magnitude in September and then gradually
increase in brightness to 0.0 magnitude in December. During this month Saturn is at opposition on the 13th and the moon is
closeby on the 24th.
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 is in Aquarius throughout 2005. By the end of January the planet sets
before 20.00h with the moon closeby on the 13th.
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 is in Capricorn throughout 2005. By the end of January the planet sets
about sunset with the moon closeby on the 11th.
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.|
||Last quarter: 3rd at 19.00h
New moon: 10th at 13.00h
First quarter: 17th at 08.00h
Full moon: 25th at 12.00h
Other Objects & Events
||Eclipses during 2005:
8th April - Annular-Total eclipse of the Sun.
An annular eclipse is when the Moon appears too small to cover the Sun and a ring of the Sun's surface remains
showing at mid-eclipse. A total eclipse is when the Moon completely covers the Sun. The curvature of the Earth's surface
can cause an eclipse to be annular or total at different points along its track. The 8th April eclipse is annular-total
with a track across the Pacific Ocean, Central America and northern South America near sunset. A partial eclipse is visible
from the USA, Mexico, Central America and the west coast of South America.
24th April - Penumbral eclipse of the Moon.
A penumbral eclipse is when the Moon enters the outer or penumbral shadow of the Earth and darkens only slightly.
This eclipse is visible from the Pacific Ocean, Americas, Australia and part of Antarctica.
3rd October - Annular eclipse of the Sun.
Visible from Iberia, North Africa, the Sudan, East Africa and the Indian Ocean. In Spain the annular phase
lasts up to 4 minutes at about 11.00h.
17th October - Partial eclipse of the Moon.
In a partial eclipse only part of the Moon passes through the Earth's dark umbral shadow, the rest through
the lighter penumbra. During this eclipse only the extreme southern part of the Moon will pass through the umbra. Visible
from the Pacific Ocean, Arctic Ocean, East Asia, Indonesia and Australia.
||Meteor Showers in 2005:
Favourable conditions for viewing meteors are between last and first quarter moon during the
new moon, as moonlight seriously interferes with the number of faint meteors that can be seen. The best way to observe meteors
is to lie outdoors in a recling chair or sun-lounger. Try to take in as much of the sky as possible. When you see a meteor
mentally trace it backwards until you arrive at the radiant point.
2nd-4th January - The Quadrantids.
The average hourly rate is about 10. Conditions are favourable with a last quarter moon on the 3rd. The
radiant is low in the north during evening time.
21st-22nd April - The Lyrids.
Again the average hourly rate is expected to be about 10. Viewing unfavourable with a full moon on the 24th.
11-14th August - The Perseids.
The average hourly rate is expected to be about 60. Conditions are favourable with a first quarter moon on
the 13th. In 2002 we viewed the Perseids when the hourly rate was predicted at 60 but in fact counted at least 150 during one and a half hours on the 12th.
20th-22nd October - The Orionids.
An average hourly rate of between 10 and 20 with bad visibility with a full moon on the 17th.
Late October continuing until late November - The Taurids.
The average hourly rate is between 5 and 10. These are slow meteors from below Pleiades.
16th-18th November - The Leonids.
Unpredictable average hourly rate but with a possibility of a strong shower. Visibiltiy poor this year with a
full moon on the 16th.
12th-14th December - The Geminids.
Average hourly rate of 60 with poor viewing as the full moon falls on the 15th.
||Spring equinox 2005: March 20th at 13.00h GMT
Autumn equinox 2005: 22nd September at 22.00h GMT.
||Summer solstice 2005: June 21st at 7.00h GMT
Winter solstice 2005: 21st December at 19.00h GMT.
||Spanish and British summer time begin on March 27th 2005.
Spanish and British winter time begin on October 30th 2005.
Note: Spanish summer time is 2 hours ahead of Greenwich Mean Time and British summer time is 1 hour ahead of GMT.
Spanish winter time is 1 hour ahead of GMT and British winter time equals GMT.
||We say that a planet is in conjunction with another planet or object when the two are in line as viewed from the earth. They are of no real astronomical importance, except that a planet in conjunction with the sun will obviously not be visible in the night sky. Planets in conjunction with each other make an attractive spectacle.
As inner planets, Mercury and Venus have inferior and superior solar conjunctions.
Inferior conjunction is when a planet lies between the earth and the sun and superior conjunction is when a planet lies
behind the sun. The outer planets may only have superior conjunctions with the sun.
Inferior Conjunctions - 29th March, 6th August and 24th November.
Superior Conjunctions - 14th February, 3rd June and 18th September
Last Inferior Conjunction - 8th June 2004 when Venus also transited the sun.
Superior Conjunction - 31st March.
Jupiter - 22nd October.
Saturn - 23rd July.
Uranus - 25th February.
Neptune - 3rd February.
||Oppositions occur when an outer planet is in the opposite side of the sky from the sun as viewed from the earth. Mercury and Venus can never be at opposition since they are inside of the earth's orbit and, therefore, remain relatively close to the sun.
The planets travel in elliptical, rather than circular, orbits around the sun which means the distance to the sun varies. Oppositions can occur when a planet is closest to the sun (at perihelion) or when a planet is furthest from the sun (at aphelion), or at any time between the two. The most favourable oppositions for viewing are at perihelic opposition as this is also the time the opposing planet is closest to the earth.
Mars appears almost twice as large at perihelic opposition at 56.3 million kilometres from the earth, as at aphelic opposition when it is 100 million kilometres from the earth.
Mars - 7th November at -2.3 magnitude in Aries.
Jupiter - 3rd April at -2.4 magnitude in Virgo.
Saturn - 13th January at -2.4 magnitude in Gemini.
Uranus - 1st September at 5.6 magnitude in Aquarius.
Neptune - 8th August at 7.9 magnitude in Capricorn.
Retrograde & Stationary
|As seen from the earth, the motion of all planets is eastwards taken over the whole year. As the earth is also moving, and more quickly than the outer planets, it overtakes them around the time of opposition. At this time the outer planets appear to move backwards against the stars.
The term used to descibe this backwards motion is 'retrograde', as opposed to the normal motion described as 'direct'. The point at which the motion changes from direct to retrograde, or back again, is when a planet is said to be 'stationary'.
In the diagram the direct motion to the east is shown at positions 1,2 and 3, backward motion to the west at 4 and 5, and direct motion to the east again at 6 and 7.
Mars has a direct motion until 1st October when stationary in Aries, retrograde
through opposition on 7th November, stationary again on the 10th December after which Mars resumes direct motion still in
Jupiter is direct until stationary on the 2nd February, retrograde moving
westwards against the stars through opposition on the 3rd April. It becomes stationary again on the 5th June after which it
moves again into direct easterly motion. In Virgo throughout.
Saturn, in Gemini, begins 2005 following a retrograde path through opposition on
13th January until stationary on 22nd March after which it follows a direct motion. Moving into Cancer in June, Saturn is
stationary again on 22nd November from when it follows a retrograde path into 2006.
Neptune, in Capricorn, is stationary on the 20th May, at opposition on the 8th
August and stationary again on the 26th October.
||Venus and Mercury orbit the sun inside of the Earth's orbit. Since neither planet revolves around the sun in exactly the same plane as the earth, they usually do not pass directly in front of the sun. Such a passage, which happens at inferior conjunction, across the sun's disk is called a transit. It is not an eclipse because they appear only as a black dot on the solar disk.
Transits of Venus are rare, taking place at over 100 year intervals
and usually in pairs. The last pair of transits of Venus were in 1874 and 1882.
2004 - The first of a current pair was on 8th June 2004 which began early morning, wholly
visible from Europe.
2012 - The second of this pair is in late June 2012. After that
transits of Venus won't occur again until 2117 and 2125.
Transits of Mercury are more frequent and take place in May and November.
2003 - The most recent transits of Mercury were in 1993 and 1999 and then in 2003 on 7th May. On the latter date a transit commenced
from the upper left-hand side of the sun at about 7.00h SST, crossing the upper part of the sun from left to right, and
left at about 12.45h SST. At this time Mercury was at such a distance from the earth that it was not visible to the naked
eye. It is safe to project the sun's image by means of a small telescope onto a white card.
2008 - The next transit of Mercury will be on 8th November 2008.