What the Planets are doing this month
Mercury. The innermost planet reaches its greatest western elongation from the Sun on the second day of the New Year when it will be rising ninety minutes before the Sun. Make the most of the first half of January as by the end of the month Mercury will be too close to the Sun to be safely observed. On the 13th and 14th of the month Mercury and Saturn will be less than one degree apart and on the 15th a thin waning crescent Moon lies less than six degrees to the west of Mercury.
Venus. Too close to the Sun for observation this month as it reaches superior conjunction with the Sun on the 9th of January. After conjunction it moves into the western evening sky, once again becoming the "Evening Star" and where it will remain until the end of October.
Mars. Jupiter. These two planets don't stray too far from each other for the entire month, never getting more than eleven degrees apart. They start the month in Libra only three degrees apart and close to alpha Librae (Zubenelgenubi), Libra's second brightest star which on the ancient star charts marked the northern claw of the Scorpion. On its easterly journey against the background stars Mars will slip past Jupiter on the 7th when the two bodies will be less than half a degree apart and visible together in a telescopic eyepiece. The waning crescent Moon passes by the pair on the 11th and 12th of the month while Mars, continuing its eastward motion, slips into the mouth the scorpion on the last day of the month.
Saturn. The ringed planet once again rejoins the morning twilight but probably too close to the Sun and too risky to observe until at least the middle of the month when it will rise ninety minutes before the Sun. By month's end it will rise almost three hours before the Sun and in a much darker sky. It will be in close conjunction with Mercury on the 13th and 14th and a waning crescent Moon will be four degrees to the north of Saturn on the 15th of the month.
Moon Phase for January 2018:
2nd 9th 17th 25th 31st *1st "Blue Moon" for 2018
The second Full Moon in a month is referred to as a "Blue Moon"
Mercury. Venus. The two inner planets, Mercury and Venus are both too close to the Sun for observation this month. Mercury in at superior conjunction with the Sun on February the 17th, and moving from the early morning twilight to the early evening twilight. Venus, having passed superior conjunction last month has now entered the early evening sky but still a little close too the Sun to be observed safely. Best to find other things to look at this month.
Mars. The red planet rises five hours before the Sun at the beginning of February but by the end of the month will rise just before midnight and a full six hours before the Sun. It spends the first eight days of the month in Scorpius, passing two degrees to the north of seventh magnitude globular cluster M80 on the 6th and moving into Ophiuchus on the 9th of the month. A waning crescent Moon joins Mars on the 9th and 10th of February.
Jupiter. Balancing on the scales of Libra, the massive giant planet rises just before midnight as February begins but by the end of the month enters the eastern sky around 11:00pm. The waning crescent Moon is situated five degrees to the north of Jupiter on the 8th with beta Librae (Zubeneschamali) a further three degrees to the north. This magnitude 2.6 star is one of the very rare bright stars to show a distinct greenish tinge and lies at a distance of 120 light years.
Saturn. The ringed planet is situated among the dense star fields of Sagittarius but readily identified by its subtle yellow hue. Because of its thirty year journey around the Sun it appears to move very little against the background stars and in fact only travels two degrees over the entire month. It will rise around 2:00am in the middle of the month and will be joined by the waning crescent Moon on the 12th of the month.
Moon Phase for February 2018:
8th 16th 23rd * No Full Moon this month
Mercury. March is not the best month to observe the illusive inner planet as even at its greatest eastern elongation from the Sun on the 15th of the month it will be setting only forty minutes later than the Sun and hard to spot in the western twilight. This date will offer the best opportunity to view Mercury as the much brighter Venus will be situated four degrees to its south.
Venus. Having returned to the evening sky early in January, Venus is slowly increasing its eastern elongation from the Sun and by the end of March will set almost one hour later than the Sun. On the 19th of the month a thin waxing crescent Moon sits five degrees above Venus and on the 29th Venus will pass within half a degree of magnitude 5.8 Uranus. This will be a great opportunity to observe both planets in the same field of a wide field eyepiece.
Mars. The red planet rises before midnight by the middle of March among the brilliant star fields of Sagittarius. It begins the month in Ophiuchus, moving into Sagittarius on the 12th and passing between the Lagoon and Trifid Nebulae on the 19th and 20th of the month. Continuing on its eastward journey against the background stars it encounters the magnificent globular cluster M22 on the last day of the month, the pair being separated by just over one degree. Saturn is also close by on this date and only two degrees lies between the two planets. The last quarter Moon pays Mars a visit on the 10th of the month.
Jupiter. At the beginning of the month Jupiter will be rising around 11pm and by the end of the month a full two hours earlier. It still hovers above the scales of Libra where it is joined by the Moon on the 7th and 8th of March. On the 10th it begins its four months of retrograde motion, moving from east to west against the background stars until the 10th of July when it will resume its eastward journey.
Saturn. The ringed planet opens the month in Sagittarius within two degrees of magnitude 5.1 globular cluster M22 with the fainter globular NGC 6642 even closer and only one degree away. Because of its almost thirty year journey around the Sun, Saturn will keep this pair as companions for the entire month. Mars visits toward the end of the month and on the last day of the month is only eleven arc minutes from NGC 6642. With the two planets so close together this is a good time to note the apparent difference in colour of the two with Mars a distinct orange colour and Saturn sporting a subtle yellowish tone. The Moon also pays Saturn a visit on the 11th of March.
2nd 9th 17th 25th 31st * 2nd "Blue Moon" for 2018
The second Full Moon in a month is referred to as a "Blue Moon"
Mercury. After inferior conjunction with the Sun on the 2nd, Mercury returns the early morning eastern sky. Rising a little earlier than the sun each morning as the month progresses it reaches its greatest elongation west of the Sun on the 30th of the month. It spends most of April in Pisces, moving into Cetus on the 23rd where it remains for the rest of the month. The wafer thin crescent of the waning Moon rises forty minutes before Mercury on the 14th.
Venus. Setting almost one hour later than the Sun at the beginning of April, Venus is well on its way to becoming the brilliant "Evening Star". Setting slightly later than the Sun each day as the month progresses, by the end of the month it will set 90 minutes later than the Sun. It begins the month in Aries, crossing into Taurus on the 20th where it will spend a few days within five degrees of the magnificent Pleiades (Seven Sisters) star cluster. The thin crescent of a waxing two day old Moon will set half an hour later than Venus on the 18th of the month.
Mars and Saturn. The red planet begins the month in Sagittarius, very close to Saturn and on the 3rd only 75 arcminutes separate the pair. Check out the different colours of the two with Mars a distinct orange and Saturn with its subtle yellow tinge. Mars quickly moves away from its yellow companion and by the end of April the two are separated by fourteen degrees. On the 1st of the month, Mars is less than half a degree from 8.8 magnitude globular cluster NGC 6642 and the next day passes a similar distance from the spectacular magnitude 5 globular cluster M22. The waning last quarter Moon makes an equilateral triangle with the two planets on the 8th of the month.
Jupiter. The giant planet rises around 8:00pm at the start of the month but by month's end will cross the eastern horizon two hours earlier. Still retrograding in Libra it is joined by a waning gibbous Moon on the 4th of April.
The "JUPITER 2" program is a free download and will give you the positions of the Galilean moons for any date you set it for.
8th 16th 23rd 30th
Mercury. For the first half of May, Mercury is in a good position for observation. In the early morning twilight the inner planet begins the month in Pisces and moves into Aries on the 16th of the month. It will be rising two hours before the Sun on the 1st but gets a little later as each day passes until the 26th when it will be close to the eastern horizon and rising less than an hour before the Sun making it harder to observe because of the glare of the Sun. On the 14th Mercury Uranus and the thin waning crescent Moon will be within a five degree circle and worth a look in a pair of binoculars.
Venus. Obvious in the early evening western sky not long after sunset the "Evening Star" begins the month in Taurus, moving into Gemini on the 20th. The next evening finds it less than one degree from the open cluster M35 with the pair accessible together in a wide field eyepiece. The third magnitude star epsilon Geminorum (Mebsuta) is swamped by the light of Venus on the 28th with the pair only a few arc minutes apart. The thin waxing crescent Moon pays Venus a visit on the 17th and 18th of May.
Mars. The red planet rises around 10pm at the beginning of May but by the end of the month will cross the eastern horizon a full hour earlier. As it crosses from Sagittarius into Capricornus on the 14th it has a close encounter with the magnitude 8.6 globular cluster M75 with less than half a degree separating the two. M75 lie at a distance of 67,500 light years and because of its distance requires a fairly large telescope to begin resolving its stars. On the 5th and 6th of the month the waning gibbous Moon pays Mars a brief visit.
Jupiter. The brilliant giant planet is at opposition on the 9th of this month and in an ideal position for observation all night long. Even small binoculars will reveal the dancing Galilean moons changing their positions from night to night in relation to the planet and to each other. Jupiter is retrograding at the moment and by the end of the month sits less than a degree from magnitude 2.9 alpha Librae (Zubenelgenubi), a star that on the ancient star charts marked the southern claw of the scorpion. An almost full Moon visits Jupiter on the 1st and again on the 27th of the Month.
Saturn. The magnificent ringed planet rises around 9:00pm at the beginning of May but by the end of the month will be rising a full two hours earlier. This magnificent planet has no equal as a spectacle in the entire solar system and even a small telescope will highlight its magnificent ring system. Make the most of this apparition as the angle of the rings as seen from the Earth will slowly close down over the next few years until by 2025 when the rings will appear to disappear for a short time. On the 4th of the month only three degrees separate Saturn and the waning gibbous Moon.
Moon Phase for May 2018:
8th 15th 22nd 19th
Mercury: The inner planet reaches superior conjunction with the Sun on the 6th before entering the western evening twilight. It will not be safely observable until the middle of the month when it resides in Gemini where on the 25th it will be in conjunction with magnitude 1.1 Pollux (beta Geminorum), an orange giant which lies at a distance of 36 light years. At Magnitude 0.38, Mercury will be the brighter of the two.
Venus: Brighter than all other heavenly bodies except the Sun and the Moon, Venus can easily lay claim to the title of the "Evening Star". At the start of June Venus is also in Gemini and setting two and a half hours later than the Sun. It will move into Cancer on the 12th of the month where it passes less than half a degree from the centre of M44 (The Beehive Cluster) on the 20th before moving into Leo on the 29th. A thin waxing crescent Moon sits less than a degree to the west of Venus on June 16th.
Mars: The red planet will be rising just prior to 9:00pm at the onset of June but by the end of the month will crest the eastern horizon around 7:15pm. It spends the entire month in Capricornus where it encounters the Moon twice this month, once on the 3rd and again on the 30th. There are no stars brighter than 3rd magnitude in this constellation so brilliant Mars dominates the entire scene. The magnitude 7.5 globular cluster M30 is worth a look at while you are in that area of the sky. It can be located three degrees to the east of magnitude 3.7 zeta Capricornus.
Jupiter: The giant planet spends the entire month retrograding in Libra and for the first nine days within one degree of Zubenelgenubi (The Southern Claw), Libra's second brightest star. At the beginning of the month Jupiter rises around 3:30pm and so by nightfall can be located high in the eastern sky in an ideal location for observation. The Moon will bypass Jupiter between the 23rd and 24th of June.
Saturn: The magnificent ringed planet reaches opposition on the 27th of the month and will be in a position for observation for the entire night. In Sagittarius, Saturn begins the month less than two degree from the fifth magnitude globular cluster M22 with the waning gibbous Moon six degrees to the east of the pair. The 5.8 magnitude asteroid Vesta is also nearby and less than five degrees to the north-west of Saturn on the 1st of the month. The full Moon encounters Saturn again on the 28th of the month.
Moon Phase for June 2018:
7th 14th 20th 28th
Mercury: July is a great month to observe the elusive inner planet. It begins the month in the western evening sky in Cancer where on the 4th it will pass less than a degree to the south of the Beehive star cluster and on the 5th and 6th sits less than one degree to the north of the magnitude 3.9 yellow giant, delta Cancris. On the 12th Mercury finds itself at its greatest elongation east of the Sun and commences its journey westward and conjunction with the Sun early next month. It moves into Leo on the 15th where it encounters the two day old waxing crescent Moon.
Venus: The brilliant "Morning Star" is easily located high in the western evening after sunset just south of the head of Leo-The Lion. It spends the entire month crossing from one side of Leo to the other and on the way encounters magnitude 1.4 Regulus, the constitution's brightest star on the 10th of the month. This star is a blue-white son 85 light years away and has a wide magnitude 7.6 companion visible in telescopes and small binoculars. There will be no mistaking which is which as Venus outshines Regulus by a full 2.6 magnitudes. A waxing crescent Moon is situated four degrees to the north of Venus on the 16th of July.
Mars: The red planet spends the entire month retrograding in Capricorn. On the first day of July it will rise at 7:10pm but by the end of the month will breach the eastern horizon around 4:30pm and easily observable in the early evening sky. On the 15th it makes its closest approach, just over one degree, to magnitude 4.1 psi Capricorni, a yellow-white dwarf, 48 light years away. The full Moon will be seven degrees to the north-west of Mars on the 27th of the month.
Jupiter: Retrograding in Libra until the 11th when the giant planet becomes stationary in relation to the stars after which it returns to its eastward motion against the starry backdrop. Jupiter will be the brightest object in that part of the sky until dominated by the waxing gibbous Moon on the 20th and 21st of the month. It crosses the meridian around 7:00pm mid month and so is in an ideal position for observation early in the evening for the entire month.
Saturn: Low in the eastern evening sky after the sun has set; Saturn is in an ideal position for observation all night long for the entire month of July. Still retrograding in Sagittarius the magnificent ringed planet never strays more than five degrees from the brilliant fifth magnitude globular cluster M22, a great sight in any moderate sized telescope. The asteroid 4 Vesta remains around ten degrees to the west of Saturn during the month and at magnitude six should be easy to find. The waxing gibbous Moon pays Saturn a visit on the 25th of July.
Moon Phase for July 2018:
6th 13th 20th 28th
Mercury. The inner planet reaches inferior conjunction with the Sun on the 9th after which it moves into the early morning sky and hard to spot. At its greatest elongation west of the Sun on the 27th it rises less than one hour before the Sun and lost in the early morning twilight. Give it a miss this month.
Venus. Unmistakable as the brilliant "Evening Star", Venus spends the entire month of August in Virgo having moved into that constellation on the 1st. Traveling eastward through Virgo it encounters beta Virginis in the 4th, gamma Virginis on the 18th and is within two degrees of Spica, Virgo's brightest star on the last day of the month. The waxing crescent Moon passes by Venus on the 14th and 15th of August.
Mars. Rising at 4:30pm Mars shines brilliantly high in the eastern sky after sunset at the beginning of the month and in an ideal position for observation the entire month. It spends the first 23 days in Capricornus and then spends the rest of the month perched on the border of Capricornus and Sagittarius. The waxing gibbous Moon will be seven degrees to the north of Mars on the 23rd of the month.
Jupiter. High in the northern sky and just west of the meridian at the beginning of August this is still a great time to observe the giant planet and witness the dance of its Galilean moons. On the 17th it makes its closest approach to alpha Librae (Zubenelgenubi, The Southern Claw) when the pair is 34 arcminutes apart. This star is a wide binocular double consisting of a magnitude 2.8 blue-white star and a magnitude 5.2 white star. A waxing gibbous Moon will also be in attendance on this day.
Saturn. Still slowly retrograding in Sagittarius and rising around 1:30pm mid month, Saturn is ideally situated for observation this month. Looking brilliant among the vast star fields of the central Milky Way its golden hew stands out against the milkiness if these magnificent star fields. The waxing gibbous Moon is two degrees to the north of Saturn on the 21st of August.
Moon Phase for August 2018:
5th 11th 18th 26th
Mercury. Low in the eastern twilight just before sunrise at the beginning of September, Mercury will be a difficult target for observers this month. It rises forty five minutes before the Sun on the 1st of the month and is in superior conjunction with the Sun on the 21st. It will then appear in the western evening twilight but too close to the Sun to safely observe for the rest of the month. October will see Mercury in a much more favorable position to be observed.
Venus. Shining like a searchlight beacon high in the western evening sky after sunset, the "Evening Star" spends the entire month in Virgo. The 1st of September finds it a little over one degree to the south west of Virgo's brightest star Spica, a blue white star 260 light years away. The thin crescent of a waxing Moon joins Venus on the 12th and 13th of the month, a pleasant sight in the western evening sky.
Mars. Still hanging around in Capricornus where it will be all of September, Mars is still in a very favorable position for observation. High in the north eastern sky after sunset, it crosses the meridian around 9:30pm at the beginning of September but by the end of the month will cross the meridian around 8:00pm. At the time of writing (early August) the red planet was experiencing a severe dust storm and features on its surface very hard to distinguish. These storms can sometimes last for months so conditions may not have improved for September, fingers crossed. A waxing gibbous Moon lies five degrees to the north of Mars on the 20th of the month.
Jupiter. The giant planet still resides in Libra where it has been since last November and will be low in the western sky after sunset at the beginning of September. By the end of the month it will be setting reasonably early, around 9:30pm so make the most of this month as by the end of October it sets at 9:00pm. The waxing crescent Moon will be four degrees to the north of Jupiter on the 14th of September.
Saturn. Still the "star" of the show, Saturn reigns supreme high in the north western sky after sunset early in September and in a great position for observation. It is in illustrious company at the beginning of the month. It is just over one degree from the open star cluster M21, less than two degree from the Trifid Nebula M20 and just over two degrees from M8, the Lagoon Nebula. The first quarter Moon will be four degrees from Saturn on the 17th of September.
Moon Phase for September 2018:
3rd 10th 17th 25th
Mercury, Venus and Jupiter. October sees Mercury, Venus and Jupiter sharing the western evening sky. Mercury sets later and further from the Sun as the month progresses while Venus moves ever closer to the Sun with each passing day. On the 16th these two will set together just after 7:30pm. Venus continues its westward march reaching inferior conjunction with the Sun on the 27th while Mercury progresses eastward, passing three degrees to the south of Jupiter on the 29th of the month. The thin crescent of the new Moon joins the trio on the 11th and 12th of October.
Mars. The red planet is still in Capricornus where it will spend the entire month of October. The dust storm which plagued the planet on its nearest approach to the Earth in August still remains but has cleared slightly and the south polar cap and a few surface features can now be glimpsed through the thinning dust. Over the month the planet's disc shrinks from 16 arcseconds to 12 arcseconds with a significant reduction in its brightness. The waxing gibbous Moon will be three degrees to the north-west of Mars on the 18th of the month.
Saturn. Sunset finds Saturn high in the northern sky and in a good position for observation early in the evening but make the most of it as it will be setting around midnight in mid October. It begins the month two degrees to the east of Messier objects M8, M20 and M21 but moves away from them as the month progresses. The crescent Moon and Saturn will be just over three degrees apart on the 15th of the month.
Moon Phase for October 2018:
2nd 9th 17th 25th
Mercury. The inner planet can be found in the western evening sky after the Sun has set early in the month. It reaches its greatest elongation east of the Sun on the 7th when it will be setting two hours later than the Sun. Each evening after that it will set earlier until the 27th when it will reach inferior conjunction with the Sun and set at the same time as the Sun. The thin crescent of a waxing Moon will be in the vicinity of Mercury on the 9th and 10th of the month.
Venus The brightest planet returns to the morning sky this month, regaining the title of the "Morning Star". On the 15th it makes a close approach to magnitude 1.0 Spica, Virgo's brightest star when the pair will be just over one degree apart. By the end of the month Venus will be rising a full two hours before the Sun.
Mars. High in the north western sky after sunset the red planet begins the month in Capricornus, crossing into Aquarius in the 12th where it will spend the rest of the month. Its ruddy glow is unmistakable among the faint star fields of these two constellations. The waxing gibbous Moon passes two degrees to the south of Mars on the 16th of the month.
Jupiter. Only visible for the first few days of November after which it will be setting too close to the Sun for safe observation. It will attain superior conjunction with the Sun on the 26th of the month as it enters the early morning sky. It would be better ignored until mid December when it will be rising one hour before the Sun.
Saturn. High in the western evening sky in Sagittarius, the ringed planet sets just before midnight at the beginning of November but by the end of the month only two hours later than the Sun. By the end of the month it will have moved to within one and a half degrees of the magnificent fifth magnitude globular cluster, M22. The thin waxing crescent Moon sits five degrees to the west of Saturn on the 11th of the month.
Moon Phase for November 2018:
1st 8th 16th 23rd 30th
Mercury. The inner planet returns to the morning sky reaching its greatest elongation west of the Sun on the 15th of the month. On this date it will rise a little over one hour prior to the Sun having just crossed the border from Libra into Scorpius. It only remains in Scorpius for a few days crossing into Ophiuchus on the 21st where it has a close encounter with Jupiter on the 22nd. The two will be separated by less than one degree. A very thin waning crescent Moon sits two and a half degrees to the north of Mercury on the 6th of the month although the pair may be a challenge to spot in the early morning twilight.
Venus. At the onset of December, Venus rises two hours before the Sun and reigns supreme in the eastern morning sky until the rising Sun later robs it of its brilliance. It starts the month in Virgo, moving into Libra on the 14th. The thin waning crescent Moon will be four degrees to the north of Venus on the 4th of December.
Mars. The red planet begins December in Aquarius, crossing into Pisces on the 22nd of the month when it will be just south of the circlet of stars marking the head of one of the fish. Mark your calendar on the 7th of the month when Mars and Neptune will only be separated by five minutes of arc. The distance between Mars and the Earth has increased drastically since the disappointing opposition in July when a dust storm obscured most of the surface of the planet. The angular size of Mars when the two are at conjunction has shrunk to nine arc seconds but a medium sized telescope at around 200 magnification should show up the blue colour of Neptune to the contrasting red of Mars. The first Quarter Moon will be five degrees to the east of Mars on the 15th of the month.
Jupiter. Also in the early morning sky but hard to spot in the bright morning twilight at the start of the month. By the end of the month however it will rise around 4:00am, two hours before the Sun and in a better spot for observation. It begins the month in Scorpius and moves into Ophiuchus on the 14th prior to its close encounter with Mercury on the 22nd.
Saturn. The Ringed planet sets two hours later than the Sun at the beginning of December. By the middle of the month however will set only one hour after the Sun and getting harder to spot in the late evening twilight. The two day old waxing crescent Moon and Saturn will be ninety arcminutes apart on the 9th of the month.
Moon Phase for December 2018:
7th 15th 23rd 29th