January 14 Observing Guide

OBSERVING GUIDE
(Please note all times are UT and are based on the location of Belfast and covers January)

The Sun

At the start of the month, the Sun rises at 08:45 and sets at 16:10. By month's end, it rises at 08:15 and sets at 17:00.

The Planets

Mercury is at greatest eastern elongation on the 31st and is visible in the evening sky in Aquarius during the last week of the month. At month’s end it sets at 18:40 and is mag-0.6.

Venus starts the month as an evening object and is at inferior conjunction on the 11th. By month’s end, it has become a morning object in Scutum. At start of the month, it sets at 17:40 and by month's end, it rises at 06:15. It brightens from mag -4.4 to mag -4.6 during the month.

Mars is visible in the morning sky in Virgo this month and is at western quadrature on the 3rd. At the start of the month, it rises at 00:40 and by month's end at 23:45. It brightens from mag +0.8 to mag +0.3 during the month. It lies 2° to the E of Porrima (Gamma (γ) Virginis, mag +2.7) on the 1st and 6° to the N of Spica (Alpha (α) Virginis, mag +1.0) on the 23rd.

Jupiter is at opposition on the 5th and visible in the evening sky in Gemini this month. At the start of the month, it rises at 16:25 and during daylight hours by month's end. It fades from mag -2.7 to mag -2.6 during the month.

Saturn is visible in the morning sky in Libra this month. It rises at 04:30 at the start of the month and by month’s end at 02:40. It brightens from mag +0.6 to mag +0.5 during the month.

Uranus is visible in the evening sky this month in Pisces. During the month, it rises during daylight hours and sets at 22:30 by month’s end. It fades from mag +5.8 to mag +5.9 during the month and lies 6° to the SW of Linteum (Delta (δ) Piscium, mag +4.4).

Neptune is visible in the evening sky this month in Aquarius. During the month, it rises during daylight hours and sets at 19:00 by month’s end. It fades from mag +7.9 to mag +8.0 during the month and lies 4° to the S of Ancha (Theta (θ) Aquarii, mag +4.2).

The Moon

The new moon is on the 1st and the 30th with the first quarter moon on the 8th and the full moon on the 16th. The last quarter moon is on the 24th.

On the evenings of the 2nd and 3rd, the waxing crescent moon lies to the SW of Venus at around 17:00.

On the evening of the 4th, the waxing crescent moon lies to the NW of Neptune at around 19:00.

On the evening of the 7th, the waxing crescent moon lies to the NE of Uranus at around 19:00.

On the evenings of the 10th- 12th, the waxing gibbous moon lies in Taurus. On the 10th, it lies to the SW of M45 - The Pleiades. On the following evening, it lies to the S of the cluster and to the NW of Aldebaran (Alpha (α) Tauri, mag +0.9). On the 12th, it lies to the E of the star. On all three evenings, look at around 19:00.

On the evening of the 13th, the waxing gibbous moon lies to the SW of M35 at around 19:00.

On the evening of the 14th, the waxing gibbous moon lies to the W of Jupiter at around 20:00.

On the evening of the 16th, the waning gibbous moon lies to the SW of M44 – The Beehive Cluster at around 20:00.

On the evening of the 18th, the waning gibbous moon lies to the SW of Regulus (Alpha (α) Leonis, mag +1.4) at around 22:00.

On the morning of the 23rd, the waning gibbous moon lies to the SW of Mars and to the NW of Spica (Alpha (α) Virginis, mag +1.0) at around 03:00.

On the morning of the 25th, the waning crescent moon lies to the W of Saturn at around 05:00.

On the morning of the 28th, the waning crescent moon lies to the W of Venus at around 07:00.

Meteors

The best time to observe meteor showers is when the moon is below the horizon; otherwise its bright glare limits the number you will see especially the fainter ones. Below is a guide to this month's showers.

The Quadrantids peak on the 3rd at 19:30 with a ZHR of 120.However the low position of the radiant makes a much lower ZHR more realistic. The radiant is roughly where the constellations Boötes, Draco and Hercules meet low in the North and is circumpolar. The waxing crescent moon sets at 19:35 on the 3rd, allowing for good observing conditions. The shower is named after a now defunct constellation Quadrans Mualis which lay between Boötes and Draco.

There are additional minor showers this month, details of which can be found at meteorshowersonline.com/calendar.html or www.imo.net/calendar/2014

Asteroids

Asteroid (19) Fortuna is at opposition on the morning of the 8th at mag +9.7. It can be found in Gemini and is visible from 18:00 on the evening of the 7th.

Asteroid (11) Parthenope is at opposition on the morning of the 11th at mag +9.9. It can also be found in Gemini and is visible from 18:00 on the evening of the 10th.

Asteroid (18) Melpomene is at opposition on the morning of the 28th at mag +9.3. It can be found in Cancer and is visible from 19:00 on the evening of the 27th.

Finder charts and further information about other fainter asteroids can be found at; britastro.org/computing/charts_asteroid.html in the source list below.

Comets

C/2013 R1 (Lovejoy) is expected to be mag +5 and fading in January. It starts the month in Hercules and then heads into Ophiuchus by mid-month. At the start of the month it is visible in the evening sky until 19:00 and becomes visible in the morning sky from 03:00. By mid-month, it is too low to be visible in the evening sky and becomes visible in the morning sky from 04:00. Similar viewing conditions exist at month’s end. It lies near to Rasalhague (Alpha (α) Ophiuchi, mag +2.1) around the 16th.

Finder charts and further information about other fainter comets can be found at www.aerith.net , cometchasing.skyhound.com , www.ast.cam.ac.uk/%7Ejds/ , in-the-sky.org , kometen.fg-vds.de/fgk_hpe.htm , www.nightskyhunter.com/index.html and www.rasnz.org.nz in the source list below. Any above estimates for predicting a comet's brightness/status are based on current information at the time of writing the guide and the comet may be brighter/dimmer than the above predictions or may no longer be intact to observe.

Deep Sky

On the deep sky front this month, galaxies M81 and M82 can be observed in Ursa Major. In Andromeda, M31 - The Andromeda galaxy can be observed along with its satellite galaxies M32 and M110. In Perseus, there is the open cluster M34 and the excellent Double Cluster - NGC 869 and 884. In Triangulum, there is the galaxy M33. In Auriga there are three open clusters M36, M37 and M38 and also M35 in Gemini. Taurus has the excellent Pleiades - M45, the Hyades and also M1 - The Crab Nebula. Orion returns to our skies with M42 - The Great Orion Nebula and also Cancer with M44 - The Beehive Cluster.

General Notes

Always keep an eye out for Aurorae. Other interesting naked eye phenomena to look out for include the Zodiacal Light and the Gegenschein.

Both are caused by sunlight reflecting off dust particles which are present in the solar system. The Zodiacal Light can be seen in the West after evening twilight has disappeared or in the East before the morning twilight. The best time of year to see the phenomenon is late-Feb to early-April in the evening sky and September/October in the morning sky - it's then that the ecliptic, along which the cone of the zodiacal light lies, is steepest in our skies. The Gegenschein can be seen in the area of the sky opposite the sun. To view either, you must get yourself to a very dark site to cut out the light pollution. When trying to observe either of these phenomena, it is best to do so when the moon is below the horizon. A new appendix has been added explaining some of the more technical terms used in the guide.

Clear Skies

Neill McKeown

Information Sources Used and Links

www.skyviewcafe.com ; Sky at Night Magazine Observing Guide and CD; www.aerith.net ; cometchasing.skyhound.com ; www.ast.cam.ac.uk/%7Ejds/ ; kometen.fg-vds.de/fgk_hpe.htm ; www.rasnz.org.nz ; Stardust Magazine; britastro.org/computing/charts_asteroid.html ; in-the-sky.org ; www.nightskyhunter.com/index.html www.eagleseye.me.uk/Sky/Wordpress/;http:...meris/ephemeris.html ; eco.mtk.nao.ac.jp/cgi-bin/koyomi/cande/phenomena_en.cgi ;
Philip's Stargazing 2014; Patrick Moore's 2014 Yearbook of Astronomy; www.heavens-above.com ; www.spaceweather.com ;meteorshowersonline.com/calendar.html ; www.timeanddate.com/astronomy/ ; www.imo.net/calendar/2014 - International Meteor Organisation; messier.seds.org/ - The Messier Catalogue website; www.seds.org/messier/xtra/ngc/ngc.html - NGC Catalogue website; www.irishastronomy.org - Irish Federation of Astronomy Societies Website; irishastro.org.uk/- Irish Astronomical Association website; www.eaas.co.uk - Northern Ireland Amateur Astronomy Society;

Appendix

The ZHR or Zenithal Hourly Rate is the number of meteors an observer would see in one hour under a clear, dark sky with a limiting apparent magnitude of 6.5 and if the radiant of the shower were in the zenith. The rate that can effectively be seen is nearly always lower and decreases as the radiant is closer to the horizon. The Zenith is the overhead point in the sky.

The radiant is the point in the sky, from which (to a planetary observer) meteors appear to originate, i.e. the Perseids, for example, are meteors which appear to come from a point within the constellation of Perseus. When the radiant is quoted as "circumpolar", it is never below the horizon and visible all night, otherwise the times quoted are when the constellation in which the radiant lies rises above the horizon in the East.

A fireball is defined by the International Astronomical Union as a meteor brighter than any of the planets, i.e. magnitude -4 or brighter. The International Meteor Organisation alternatively defines it as a meteor which would have a magnitude of -3 or brighter at the zenith.

The ° symbol in the guide is that for degrees. A degree is two full moon widths to give an idea for judging any distances quoted in the guide. There are 60 arcminutes in a degree.

An asterism is a collection of stars seen in Earth's sky which form simple patterns which are easy to identify, i.e. the Big Dipper. They can be formed from stars within the same constellation or by stars from more than one constellation. Like the constellations, they are a line of sight phenomenon and the stars whilst visible in the same general direction, are not physically related and are often at significantly different distances from Earth.

Mag is short for magnitude which is the measure of an object's brightness. The smaller the number, the brighter the object. The brightest object in the sky is the Sun at mag -26, the full moon is mag -12 and Venus the brightest planet is mag -4. The brightest stars are mag -1. If there is a 1 mag difference between two objects - there is a difference in brightness of a factor of 2.5 between the two objects. For example the full moon is eight magnitudes brighter than Venus on average which means it is 1,526 times brighter than Venus. Objects down to mag +6 can be seen with the naked eye under very dark skies.

Local time is always quoted in the guide and this means for November - February - universal time (UT)/GMT is used and for April to September - daylight savings time (DST, = GMT+1). For the months of March and October when the clocks go forward/back respectively, both times will be used and attention should be paid to any times at the end of these months for that change.

Deep Sky Objects such as galaxies, nebulae and star clusters are classified in catalogues such as the Messier catalogue for objects like M44 - M for Messier. Another example of a catalogue would the New General catalogue whose objects have the prefix NGC. There are links for websites to both catalogues in the section above.

Perihelion is the point in the orbit of a planet, asteroid or comet where it is at the nearest point in its orbit to the sun. It is the opposite of Aphelion, which is when the object is at the farthest point in its orbit from the sun. For the earth, the comparative terms used are perigee and apogee and for the moon, pericynthion and apocynthion are sometimes used.



The Planets

From Earth - Mercury and Venus are the inner planets in the solar system and Mars, Jupiter, Saturn, Uranus and Neptune are the outer planets. Below is a short guide as to how both the inner and outer planets move around the sun. The above pictorial guide should hopefully help in this.

The Inner Planets

These are best seen when at Greatest Eastern/Western elongation and are not visible when at either Inferior/Superior conjunction. Greatest Eastern elongation is when the inner planet is at its furthest point east from the sun as seen from Earth and visible in the evening sky in the West after sunset, Western elongation is when it’s at its furthest point west from the sun as seen from Earth and visible in the morning sky in the East before sunset. Inferior conjunction occurs when the inner planet is between the Sun and the Earth. Superior conjunction occurs when the inner planet is on the other side of the Sun as seen from Earth.

From our Northerly latitudes, the ecliptic, along which the planets move, lies at a very shallow angle to the horizon after sunset in the autumn and before sunrise in the spring. This means that any of the planets will be difficult to see when fairly close to the Sun in the evening sky in the autumn or in the morning sky in the spring. In particular, Mercury is more or less invisible from here when at Eastern elongation in the autumn or at Western elongation in the spring, because it lies so close to the horizon and is never above the horizon except in daylight or bright twilight.

The normal cycle for an inner planet is Superior Conjunction - Greatest Eastern Elongation - Inferior Conjunction - Greatest Western Elongation - Superior Conjunction. After superior conjunction, the planet moves away from the Sun as seen from Earth and becomes visible in the evening sky after a period of time. It then moves past the point of Greatest Eastern Elongation and moves back towards the Sun as seen from Earth until a point when it is not visible and at Inferior Conjunction. After this the planet appears in the morning sky for a time, before again slipping into the Sun's glare as seen from Earth. The duration of this cycle will depend on the planet's closeness to the Sun, i.e. Mercury completes the above cycle in around 4 months.

The Outer Planets

These are best seen when at opposition and are not visible when at conjunction. Opposition occurs when the earth is between the sun and the outer planet. It is the best time to observe them because the planet is visible all through the night and it is due South and at its highest at about midnight. The planet is also at its closest point in its orbit to Earth - making it appear brighter. Conjunction occurs when the outer planet is on the other side of the Sun as seen from Earth.

If the planet is at or near it furthest point South along the ecliptic, then it won't get very high in the sky even at opposition - just as the Sun never gets high in the sky in midwinter. This happens when opposition occurs near midsummer when the planet is opposite the Sun in the sky and in midsummer the Sun is high, so the planet will be low. The opposite of course applies in winter.

The normal cycle for an outer planet is Conjunction - Western Quadrature - Opposition - Eastern Quadrature - Conjunction. After conjunction, the planet moves away from the Sun as seen from Earth and becomes visible again. The planet from this point on rises earlier and earlier in the morning sky and eventually becomes visible in the evening sky. At Western Quadrature it is at its highest at sunrise and by opposition it is in the same position by midnight. By Eastern Quadrature, it is past its best and is at its highest at sunset, meaning it is rising in daytime and setting earlier and earlier until a point when it sets too close to the Sun as seen from Earth and is no longer visible. The duration of this cycle will depend on the planet's closeness to the Sun, i.e. Jupiter completes the above cycle in around 13-14 months.

As always, thanks Neill.

Hi,

Unable to create new topic, so replying to the Jan 14 guide to post the Feb 14 guide.

OBSERVING GUIDE
(Please note all times are UT and are based on the location of Belfast and covers February)

The Sun

At the start of the month, the Sun rises at 08:15 and sets at 17:00. By month's end, it rises at 07:15 and sets at 17:55.

The Planets

Mercury is visible in the evening sky during the first week of the month, but is then at inferior conjunction on the 15th and not visible for the rest of the month. At the start of the month it sets at 18:45 and is mag-0.5.

Venus is a morning object in Sagittarius during the month. At start of the month, it rises at 06:10 and by month's end, it rises at 05:20. It maintains its brightness at mag -4.6 during the month.

Mars is visible in the morning sky in Virgo this month. At the start of the month, it rises at 23:45and by month's end at 22:20. It brightens from mag +0.2 to mag -0.4 during the month.

Jupiter is visible in the evening sky in Gemini this month. During the month, it rises during daylight hours and sets at 05:05 by month’s end. It fades from mag -2.6 to mag -2.4 during the month.

Saturn is visible in the morning sky in Libra this month and is at western quadrature on the 11th. It rises at 02:40 at the start of the month and by month’s end at 00:55. It brightens from mag +0.5 to mag +0.4 during the month.

Uranus is visible in the evening sky this month in Pisces. During the month, it rises during daylight hours and sets at 20:45 by month’s end. It maintains its brightness at mag +5.9 during the month and lies 5° to the SW of Linteum (Delta (δ) Piscium, mag +4.4).

Neptune is at conjunction on the 23rd and is not visible this month.

The Moon

The first quarter moon is on the 6th with the full moon on the 14th and the last quarter moon is on the 22nd.

On the evening of the 1st, the waxing crescent moon lies to the N of Mercury at around 18:00.

On the evening of the 3rd, the waxing crescent moon lies 3° to the W of Uranus at around 19:00.

On the evenings of the 7th and 8th, the waxing gibbous moon lies near to Aldebaran (Alpha (α) Tauri, mag +0.9). On the 7th, it lies to the W of the star and also lies to the S of M45 - The Pleiades. On the 8th, it lies 3° to the NE of the star. On both evenings, look at around 19:00.

On the evenings of the 10th and 11th, the waxing gibbous moon lies near to Jupiter. On the 10th, it lies 8° to the SW of the planet and on the 11th; it lies to the SE of it. On both evenings, look at around 19:00.

On the evening of the 13th, the waxing gibbous moon lies 1° to the SE of M67at around 20:00.

On the evening of the 14th, the waxing gibbous moon lies 8° to the W of Regulus (Alpha (α) Leonis, mag +1.4) at around 20:00.

On the mornings of the 19th and 20th, the waning gibbous moon lies near to Mars and Spica (Alpha (α) Virginis, mag +1.0). On the 19th, it lies to the NW of both objects and on the 20th, it lies 8° to the S of the planet and 6° to the SE of the star. On both mornings, look at around 01:00.

On the mornings of the 21st and 22nd, the waning gibbous moon lies near to Saturn. On the 21st, it lies to the NW of the planet and on the 22nd, it lies 5° to the SE of it. On both mornings, look at around 04:00.

On the morning of the 23rd, the waning crescent moon lies to the NE of Antares (Alpha (α) Scorpii, mag +1.0) at around 06:00.

On the morning of the 26th, the waning crescent moon lies 2° to the SE of Venus at around 07:00.

Meteors

The best time to observe meteor showers is when the moon is below the horizon; otherwise its bright glare limits the number you will see especially the fainter ones. Below is a guide to this month's showers.

There are no bright meteor showers this month.

There are additional minor showers this month, details of which can be found at meteorshowersonline.com/calendar.html or www.imo.net/calendar/2014

Asteroids

Asteroid (2) Pallas is at opposition on the morning of the 22nd at mag +7.0. It can be found in Hydra and is visible from 22:00 on the evening of the 21st.

Finder charts and further information about other fainter asteroids can be found at; britastro.org/computing/charts_asteroid.html in the source list below.

Comets

C/2013 R1 (Lovejoy) is expected to be mag +8 and fading in February. It starts the month in Ophiuchus and heads into Serpens Cauda by month end. During the month it is visible in the morning sky from 04:00.

Finder charts and further information about other fainter comets can be found at www.aerith.net , cometchasing.skyhound.com , www.ast.cam.ac.uk/%7Ejds/ , in-the-sky.org , kometen.fg-vds.de/fgk_hpe.htm , www.nightskyhunter.com/index.html and www.rasnz.org.nz in the source list below. Any above estimates for predicting a comet's brightness/status are based on current information at the time of writing the guide and the comet may be brighter/dimmer than the above predictions or may no longer be intact to observe.

Deep Sky

On the deep sky front this month, galaxies M81 and M82 can be observed in Ursa Major. In Andromeda, M31 – The Andromeda galaxy can be observed along with its satellite galaxies M32 and M110. In Perseus, there is the open cluster M34 and the excellent Double Cluster – NGC 869 and 884. In Triangulum, there is the galaxy M33. In Auriga there are three open clusters M36, M37 and M38 and also M35 in Gemini. Taurus has the excellent Pleiades – M45, the Hyades and also M1 – The Crab Nebula. Orion returns to our skies with M42 – The Great Orion Nebula and also Cancer with M44 – The Beehive Cluster and M67. Check out the constellation Canes Venatici with the globular cluster - M3 and several galaxies including M51 - the Whirlpool Galaxy and M63 - the Sunflower Galaxy. In Leo, we have several galaxies on view including The Leo Triplet - M65, M66 and NGC 3628. M95, M96 and M105 can also be observed in Leo. The place to really find galaxies is in Virgo. The Virgo Super Cluster can be found here with numerous galaxies on view. In Coma Berenices, there is M64 - the Black-Eye Galaxy.

General Notes

Always keep an eye out for Aurorae. Other interesting naked eye phenomena to look out for include the Zodiacal Light and the Gegenschein.

Both are caused by sunlight reflecting off dust particles which are present in the solar system. The Zodiacal Light can be seen in the West after evening twilight has disappeared or in the East before the morning twilight. The best time of year to see the phenomenon is late-Feb to early-April in the evening sky and September/October in the morning sky - it's then that the ecliptic, along which the cone of the zodiacal light lies, is steepest in our skies. The Gegenschein can be seen in the area of the sky opposite the sun. To view either, you must get yourself to a very dark site to cut out the light pollution. When trying to observe either of these phenomena, it is best to do so when the moon is below the horizon. A new appendix has been added explaining some of the more technical terms used in the guide.

Clear Skies

Neill McKeown

Information Sources Used and Links

www.skyviewcafe.com ; Sky at Night Magazine Observing Guide and CD; www.aerith.net ; cometchasing.skyhound.com ; www.ast.cam.ac.uk/%7Ejds/ ; kometen.fg-vds.de/fgk_hpe.htm ; www.rasnz.org.nz ; Stardust Magazine; britastro.org/computing/charts_asteroid.html ; in-the-sky.org ; www.nightskyhunter.com/index.html www.eagleseye.me.uk/Sky/Wordpress/;http:...meris/ephemeris.html ; eco.mtk.nao.ac.jp/cgi-bin/koyomi/cande/phenomena_en.cgi ;
Philip's Stargazing 2014; Patrick Moore's 2014 Yearbook of Astronomy; www.heavens-above.com ; www.spaceweather.com ;meteorshowersonline.com/calendar.html ; www.timeanddate.com/astronomy/ ; www.imo.net/calendar/2014 - International Meteor Organisation; messier.seds.org/ - The Messier Catalogue website; www.seds.org/messier/xtra/ngc/ngc.html - NGC Catalogue website; www.irishastronomy.org - Irish Federation of Astronomy Societies Website; irishastro.org.uk/- Irish Astronomical Association website; www.eaas.co.uk - Northern Ireland Amateur Astronomy Society;

Appendix

The ZHR or Zenithal Hourly Rate is the number of meteors an observer would see in one hour under a clear, dark sky with a limiting apparent magnitude of 6.5 and if the radiant of the shower were in the zenith. The rate that can effectively be seen is nearly always lower and decreases as the radiant is closer to the horizon. The Zenith is the overhead point in the sky.

The radiant is the point in the sky, from which (to a planetary observer) meteors appear to originate, i.e. the Perseids, for example, are meteors which appear to come from a point within the constellation of Perseus. When the radiant is quoted as "circumpolar", it is never below the horizon and visible all night, otherwise the times quoted are when the constellation in which the radiant lies rises above the horizon in the East.

A fireball is defined by the International Astronomical Union as a meteor brighter than any of the planets, i.e. magnitude -4 or brighter. The International Meteor Organisation alternatively defines it as a meteor which would have a magnitude of -3 or brighter at the zenith.

The ° symbol in the guide is that for degrees. A degree is two full moon widths to give an idea for judging any distances quoted in the guide. There are 60 arcminutes in a degree.

An asterism is a collection of stars seen in Earth's sky which form simple patterns which are easy to identify, i.e. the Big Dipper. They can be formed from stars within the same constellation or by stars from more than one constellation. Like the constellations, they are a line of sight phenomenon and the stars whilst visible in the same general direction, are not physically related and are often at significantly different distances from Earth.

Mag is short for magnitude which is the measure of an object's brightness. The smaller the number, the brighter the object. The brightest object in the sky is the Sun at mag -26, the full moon is mag -12 and Venus the brightest planet is mag -4. The brightest stars are mag -1. If there is a 1 mag difference between two objects - there is a difference in brightness of a factor of 2.5 between the two objects. For example the full moon is eight magnitudes brighter than Venus on average which means it is 1,526 times brighter than Venus. Objects down to mag +6 can be seen with the naked eye under very dark skies.

Local time is always quoted in the guide and this means for November - February - universal time (UT)/GMT is used and for April to September - daylight savings time (DST, = GMT+1). For the months of March and October when the clocks go forward/back respectively, both times will be used and attention should be paid to any times at the end of these months for that change.

Deep Sky Objects such as galaxies, nebulae and star clusters are classified in catalogues such as the Messier catalogue for objects like M44 - M for Messier. Another example of a catalogue would the New General catalogue whose objects have the prefix NGC. There are links for websites to both catalogues in the section above.
Perihelion is the point in the orbit of a planet, asteroid or comet where it is at the nearest point in its orbit to the sun. It is the opposite of Aphelion, which is when the object is at the farthest point in its orbit from the sun. For the earth, the comparative terms used are perigee and apogee and for the moon, pericynthion and apocynthion are sometimes used.

The Planets

From Earth - Mercury and Venus are the inner planets in the solar system and Mars, Jupiter, Saturn, Uranus and Neptune are the outer planets. Below is a short guide as to how both the inner and outer planets move around the sun. The above pictorial guide should hopefully help in this.

The Inner Planets

These are best seen when at Greatest Eastern/Western elongation and are not visible when at either Inferior/Superior conjunction. Greatest Eastern elongation is when the inner planet is at its furthest point east from the sun as seen from Earth and visible in the evening sky in the West after sunset, Western elongation is when it’s at its furthest point west from the sun as seen from Earth and visible in the morning sky in the East before sunset. Inferior conjunction occurs when the inner planet is between the Sun and the Earth. Superior conjunction occurs when the inner planet is on the other side of the Sun as seen from Earth.

From our Northerly latitudes, the ecliptic, along which the planets move, lies at a very shallow angle to the horizon after sunset in the autumn and before sunrise in the spring. This means that any of the planets will be difficult to see when fairly close to the Sun in the evening sky in the autumn or in the morning sky in the spring. In particular, Mercury is more or less invisible from here when at Eastern elongation in the autumn or at Western elongation in the spring, because it lies so close to the horizon and is never above the horizon except in daylight or bright twilight.

The normal cycle for an inner planet is Superior Conjunction - Greatest Eastern Elongation - Inferior Conjunction - Greatest Western Elongation - Superior Conjunction. After superior conjunction, the planet moves away from the Sun as seen from Earth and becomes visible in the evening sky after a period of time. It then moves past the point of Greatest Eastern Elongation and moves back towards the Sun as seen from Earth until a point when it is not visible and at Inferior Conjunction. After this the planet appears in the morning sky for a time, before again slipping into the Sun's glare as seen from Earth. The duration of this cycle will depend on the planet's closeness to the Sun, i.e. Mercury completes the above cycle in around 4 months.

The Outer Planets

These are best seen when at opposition and are not visible when at conjunction. Opposition occurs when the earth is between the sun and the outer planet. It is the best time to observe them because the planet is visible all through the night and it is due South and at its highest at about midnight. The planet is also at its closest point in its orbit to Earth - making it appear brighter. Conjunction occurs when the outer planet is on the other side of the Sun as seen from Earth.

If the planet is at or near it furthest point South along the ecliptic, then it won't get very high in the sky even at opposition - just as the Sun never gets high in the sky in midwinter. This happens when opposition occurs near midsummer when the planet is opposite the Sun in the sky and in midsummer the Sun is high, so the planet will be low. The opposite of course applies in winter.

The normal cycle for an outer planet is Conjunction - Western Quadrature - Opposition - Eastern Quadrature - Conjunction. After conjunction, the planet moves away from the Sun as seen from Earth and becomes visible again. The planet from this point on rises earlier and earlier in the morning sky and eventually becomes visible in the evening sky. At Western Quadrature it is at its highest at sunrise and by opposition it is in the same position by midnight. By Eastern Quadrature, it is past its best and is at its highest at sunset, meaning it is rising in daytime and setting earlier and earlier until a point when it sets too close to the Sun as seen from Earth and is no longer visible. The duration of this cycle will depend on the planet's closeness to the Sun, i.e. Jupiter completes the above cycle in around 13-14 months.