The Venus Evening Apparition
by Martin J. Powell
The paths of Venus and Mercury through the zodiac constellations for the later part of Venus' evening apparition in 2021-22 (click on the thumbnail for the full-size image, 228 KB). The earlier part of the planets' apparition is shown in the chart below. Positions are plotted for 0 hrs Universal Time (UT) at 5-day intervals. For Venus, apparition data for the dates shown in bright white (at 10-day intervals) are included in the table below. A Southern hemisphere version of the chart (South up) is available here (232 KB).
Both evening and morning apparitions of Mercury are included. Wherever a planet was too close to the Sun to view, the path is shown by a dashed line (- -). Hence Mercury's evening apparition ended in late September 2021 when it became lost from view in the dusk twilight. The planet was then not visible with the naked-eye until it re-emerged in the morning sky about three weeks later. Because Mercury is mostly seen by naked-eye under twilit conditions, many of the fainter stars shown in the planet's vicinity may not have been visible when the planet itself was observed.
The positions at which Venus and Mercury attained greatest elongation from the Sun are indicated by the letters 'GE', with the solar elongation angle in brackets; Eastern elongations apply for evening apparitions and Western elongations for morning apparitions. Note that the September 2021 evening apparition of Mercury shown on the chart favoured Southern hemisphere observers whilst the October morning apparition favoured Northern hemisphere observers.
A planetary conjunction of Venus with Mercury took place on December 29th, indicated on the chart by the symbol . On this date, a line drawn through the relevant planet paths (with respect to Celestial North) show them to be in alignment. For more details see the planetary conjunctions section below.
The faintest stars shown have an apparent magnitude of about +4.8. Printer-friendly versions of this chart are available for Northern (103 KB) and Southern hemisphere (104 KB) views. Click here (179 KB) to see a 'clean' star map of the area (i.e. without planet paths); a printer-friendly version can be seen here (85 KB). Astronomical co-ordinates of Right Ascension (longitude, measured Eastwards in hrs:mins) and Declination (latitude, measured in degrees North or South of the celestial equator) are marked around the border of the chart.
The eight star names shown in yellow-green were officially adopted by the International Astronomical Union (IAU) in 2017-18..
Following superior conjunction on March 26th 2021 (when it passed directly behind the Sun in central Southern Pisces, the Fishes), Venus cut across the North-western corner of the constellation of Cetus, the Whale (or Sea Monster) for a 61-hour period from 0329 UT on March 27th, re-entering Pisces through its Southern border on the following day. The planet was moving in a North-easterly direction against the background stars (direct or prograde motion) at this time.
2 0 2 1 April
Venus was unobservable through most of the month of April. The planet entered Aries, the Ram, on April 14th, passing 11°.5 South of its brightest star Hamal ( Ari or Alpha Arietis, mag. +2.0) on April 18th.
On April 22nd Venus passed 15' (15 arcminutes, where 1 arcminute = 1/60 of a degree) to the South of the planet Uranus (apparent magnitude +5.9) in a planetary conjunction which was too close to the Sun to observe. Four days later the planet Mercury (mag. -1.5), heading into the dusk sky for its second evening apparition of 2021, passed 1°.3 to the North of Venus in a conjunction which was also unobservable, taking place just 8° away from the Sun. The latter two planets would meet again in late May.
Venus' 2021-22 apparition as an 'Evening Star' commenced as the planet emerged in the dusk sky around late April. Equatorial and Northern Tropical latitudes were the first to see it, low down in the Western sky shortly after sunset. Latitudes further North began to detect the planet from around late April (at 30° North), early May (50° North) and mid-May (60° North). Southern latitudes detected the planet from around late April (at 15° South), early May (25° South) and mid-May (45° South).
A Near-Fully Illuminated Venus imaged by Manos Kardasis (Athens, Greece) on October 13th 2019 when the planet was emerging into the dusk sky for the 2019-20 evening apparition (click on the thumbnail for a larger image, 2 KB). Kardasis used a Celestron 14-inch SCT telescope fitted with a CMOS camera (Image: ALPO-Japan / Manos Kardasis)
^ Back to Top of Page
Venus was slow to emerge from the twilight glow, taking several weeks to gain a significant altitude (angle above the horizon) after sunset. As the apparition commenced Venus was positioned at a distant 1.7025 Astronomical Units (AU) from the Earth (254.7 million kms or 158.2 million statute miles), a distance which would continually reduce over the next eight months.
2 0 2 1 May
Venus entered the constellation of Taurus, the Bull, on May 3rd, reaching a solar elongation (angle from the Sun) of 10° East on the same day. Higher Northern latitudes began to see the planet from around this time, only a few degrees above the North-western horizon at dusk. From these latitudes Venus would set in twilight for much of the apparition, only beginning to set in darkness from late Autumn.
At this early stage of the apparition, when seen through a telescope, the planet showed a broad gibbous phase, around 98% illuminated, shining at magnitude -3.9 and measuring only around 10" across (i.e. 10 arcseconds, where 1" = 1/60th of an arcminute or 1/3600 of a degree). Its low altitude, great distance from the Earth and small apparent size made it a difficult object to observe telescopically, with no detail being visible in its clouds. Venus was moving along the ecliptic (the apparent path of the Sun, Moon and planets) at a steady rate of 1°.2 per day and was pulling away from the Sun at about 0°.3 per day.
Preceding Venus into the evening sky in late April was the planet Mercury. From early May the two planets began the first of three paired apparitions which took place during 2021 (a paired apparition being when the two planets are visible together for a prolonged period of time, either in the morning sky or the evening sky). At midnight UT on May 4th, Mercury - also in Taurus - was positioned 6°.4 to the ENE of Venus and was speeding away Eastwards from it a rate of about 0°.6 per day. Mercury (mag. -0.4) was 8°.3 to the ENE of Venus on May 8th.
Also on May 8th, Venus passed about 4° South of the open star cluster known as the Pleiades (Messier 45 or M45). Also known by the name The Seven Sisters, they are probably the best-known star cluster in the night sky. Under dark skies the seven brightest stars in the group can be seen with the naked-eye, however by this time of year their annual observable cycle had ended and they were too close to the Sun to see.
Venus crossed to the North of the ecliptic on May 9th. At around 2230 UT on May 12th the waxing crescent Moon passed in front of Venus, blocking it from view, in an event known as a lunar occultation. It was partly visible in twilight - just before Moonset - from a narrow strip of Pacific Ocean just to the West of South America. Details of the timings and track of visibility can be seen by following the link in the Moon near Venus Dates section below.
Mercury, having brightened to magnitude -0.0, was positioned 9°.1 to the ENE of Venus at midnight UT on May 12th; the pair were joined by the waxing crescent Moon between this day and the 14th. From mid-May Mercury began to turn more Southward and its motion began to slow, the result being that Venus slowly closed in on Mercury over the next two weeks. Mercury reached its greatest elongation on May 17th, positioned 22° East of the Sun in North-eastern Taurus, at which time Venus was 8°.8 away to its WSW. This Mercurian apparition was particularly favourable to Northern hemisphere observers.
From May 14th to 17th Venus passed several degrees to the North of the large V-shaped star cluster known as the Hyades. It comprises around 400 stars spread over an exceptionally large area of about 5° of the sky. At the South-eastern corner of the 'V', marking the 'eye' of the Bull, is Taurus' brightest star Aldebaran ( Tauri, mag. +0.9). But just like the Pleiades, the Hyades had now reached the end of their observable period as they sank into the dusk twilight.
Venus entered Chart 1 coverage on May 20th, with Mercury positioned 7°.7 to its ENE, having faded to magnitude +0.9. Venus reached 15° East of the Sun on May 23rd, by which time observers at Southern Tropical and mid-Southern latitudes had begun to detect the planet, low down in the WNW at dusk.
Table of selected data relating to the evening apparition of Venus during 2021 (click on the thumbnail for the full-size table, 66 KB). The data is listed at 10-day intervals, corresponding with the dates shown in bright white on the star charts 1 and 2. The data for the table was obtained from the software 'Redshift 5' , 'MegaStar' and 'SkyGazer Ephemeris'. The Venusian disk images were derived from NASA's Solar System Simulator.
^ Back to Top of Page
Mercury was positioned 5°.1 to the ENE of Venus at midnight UT on May 24th and 2°.4 to the East of it on May 27th. Also on May 27th, Venus passed 4°.6 South of the star Elnath ( Tau or Beta Tauri, mag. +1.6), which is located at the tip of the Bull's Northern horn. The name was standardized by the International Astronomical Union (IAU) in 2016, previous versions of the name being spelled Al Nath, El Nath or simply Nath. The star also neatly completes the six-sided figure comprising the stars of Auriga, the Charioteer, located to the North-east of Taurus.
At 0533 UT on May 29th, Venus (mag. -3.9) finally caught up with a stationary Mercury (now mag. +2.3), passing 0°.4 to the North of it in the first of three observable planetary conjunctions of Venus' 2021-22 apparition. A planetary conjunction takes place when two planets attain the same celestial longitude, so that they appear close together in the night sky. The conjunction was visible from much of the world except for higher Northern and higher Southern latitudes where twilight interfered and the altitude was low. Details of this conjunction and the other two, together with their observing circumstances, are given in the Planetary Conjunctions section below.
The star marking the tip of the Bull's Southern horn is Tianguan ( Tau or Zeta Tauri, mag. +2.9v), a 'new' name which was officially adopted by the IAU in 2017. The name Tianguan is derived from Chinese astronomy, in which it means 'Celestial Gate', an asterism (star pattern) within the 'Net' ('Bì Xiù') mansion. Venus passed 3°.0 North of the star on May 29th. The Working Group on Star Names (WGSN), a division of the IAU, has been cataloguing and standardizing the star names used by the international astronomical community since 2016. In order to accommodate a wider diversity of global culture, the WGSN has adopted some names from mythologies other than Arab, Greek and Roman, whose star names dominate the night sky. Venus passed several other 'newly-named' stars during the current apparition, some of which will be discussed below, along with a number of better-known star names (proper names) for which the IAU have now introduced standardized spellings.
Following its conjunction with Venus, Mercury's motion turned retrograde (East to West) against the background stars and the angular distance between it and Venus widened. Mercury rapidly headed back towards the Sun and became lost from view in the dusk twilight at month's end.
2 0 2 1 June
On June 1st Venus passed 17° North of the orange-red star Betelgeuse ( Ori or Alpha Orionis, mag. +0.7v), located in the neighbouring constellation of Orion, the Hunter. Betelgeuse is a variable star positioned at the North-eastern corner of the Hunter's quadrilateral figure. Its magnitude fluctuates between about +0.0 and +1.3 over a period of several years. Venus passed 4° to the North of Orion's 'club', topped by the stars 1 Ori and 2 Ori (Chi-1 and Chi-2 Orionis, mags. +4.4 and +4.6), from June 1st to 3rd.
Venus entered the constellation of Gemini, the Twins, on June 2nd, attaining its most Northerly declination (angle relative to the celestial equator) for this apparition on June 5th, at +24° 26' 5" (+24°.4347 in decimal form). Across the world, the planet now set at its most Northerly point along the local horizon, an effect which was more pronounced the further one was situated away from the Equator. For example, on June 5th at the Equator, the planet set at an azimuth (bearing from True North) of 294°, i.e. in the WNW. At latitude 55° North, the planet set at an azimuth of 317°, i.e. in the North-west - a full 23° further North along the horizon. The effect of latitude on the setting position of Venus during the 2021-22 apparition is shown to good effect in the horizon diagrams below.
Also on June 5th, Venus passed 2°.0 North of the star Propus ( Gem or Eta Geminorum, mag. +3.5v), also referred to as Tejat Prior or Praepes before IAU standardization in 2016. On June 7th the planet passed 1°.9 North of the star Tejat ( Gem or Mu Geminorum, mag. +3.0v), which marks the Northern twin's knee. The star was previously known by several other names: Tejat Posterior, Nuhatai, Calx and Pish Pai! On June 8th Venus passed 4°.2 North of the double star Gem (Nu Geminorum, mag.+4.1), which the planet will occult during its morning apparition in August 2028.
On June 9th Venus passed 8°.0 North of the star Alhena ( Gem or Gamma Geminorum, mag. +2.0), which is positioned at the foot of the Southern twin (Pollux). On June 10th the planet passed 0°.8 South of Mebsuta ( Gem or Epsilon Geminorum, mag. +3.0) which is positioned at the groin of the Northern twin. The planet attained a solar elongation of 20° East on the same day. Venus was now 10".6 in diameter and was about 94% illuminated.
A Gibbous Venus with dusky cloud markings, sketched by Paul G. Abel (Leicester, UK) on December 24th 2019 (click on the thumbnail for a larger image, 14 KB). Abel observed using an 8-inch (203 mm) Newtonian reflector telescope at 111x magnification. The planet was 84% illuminated and measured 12".7 across (Image: ALPO-Japan / Paul G. Abel)
^ Back to Top of Page
Venus passed the perihelion point in its orbit (its closest point to the Sun) on June 12th, at a solar distance of 0.7184 AU (107.5 million kms or 66.8 million statute miles). Its most distant point from the Sun - known as the aphelion - would be reached in October.
By mid-June, across the inhabited world, the planet was setting about 1½ hours after the Sun. Seen against the local horizon, Venus had been gaining altitude slowly but steadily after sundown with each passing day. From Equatorial and Southern latitudes, the planet continued to gain altitude after sunset over the coming months. In the Northern hemisphere, however, the planet's climb effectively 'stalled' during June and into early July, the result being that Venus would remain at more-or-less the same altitude at any given time after sunset for a few months to come. This was particularly prominent at high-Northern latitudes, where the planet's low altitude, narrow solar elongation and the long summer twilight combined to produce a poor evening apparition.
At around 23 hours UT on June 13th, Venus formed an isoscelene triangle with the stars Castor ( Gem or Alpha Geminorum, mag. +1.6), Gemini's second-brightest star, and Pollux ( Gem or Beta Geminorum, mag. +1.1), its brightest star, both of which were currently located to the North-east of the planet. The long sides of the triangle (Castor to Venus and Pollux to Venus) measured about 11° and the short side (Castor to Pollux) is about 4°.5. The triangle was visible at dusk from a strip of the Earth stretching from the Azores South-south-westwards to South America. From the Azores the triangle was seen in twilight, pointing more-or-less straight down to the WNW horizon; from South America the triangle was seen in twilight and/or darkness, appearing tipped on its side, pointing Southwards.
On June 14th Venus passed 3°.4 North of the optical double star Mekbuda (Gem or Zeta Geminorum, mag. +3.9v), positioned at the right knee of the Southern twin. The planet passed 1°.6 North of the star Wasat ( Gem or Delta Geminorum, mag. +3.5) on June 17th and 8°.7 South of the aforementioned Castor on June 20th.
At around 09 hours UT on June 22nd, Pollux, Gem (Kappa Geminorum, mag. +3.5) and Venus formed a line 5°.2 in length, aligned roughly celestial North and South. The angular distance between Pollux and Gem is 3°.6 and that between Gem and Venus was 1°.5. Extending the line some 17°.7 to the South of Venus brought one very close to the bright star Procyon ( CMi or Alpha Canis Minoris, mag. +0.5) in the constellation of Canis Minor, the Lesser Dog. Venus passed 1°.6 South of Gem itself at around 1040 UT that same day, and at about 15 hours UT the planet passed 5º.2 to the South of Pollux. In 2006 an exoplanet (a planet outside our Solar System) was discovered orbiting Pollux, which is 34 light years distant. Named Pollux b or Thestias (after the patronage of Leda in Greek mythology), the exoplanet is thought to have a mass equivalent to 2.3 Jupiter masses and it orbits the star at a distance of 1.6 AU in a period of 589 days. Pollux is currently one of three stars in Gemini which are confirmed as hosting exoplanets.
Venus entered Cancer, the Crab - the faintest of the zodiac constellations - on June 25th. As it did so, at around 1240 UT, Castor, Pollux and Venus formed a line some 11°.2 in length, orientated NNW-SSE. The alignment was visible at dusk from South-east Asia (South-east China, Taiwan, Thailand, Malaysia, Western Indonesia, Vietnam, Cambodia and Laos), low down over the WNW horizon. The line pointed through the South-western section of Cancer towards the head of Hydra, the Water Snake, positioned 20° to the SSE of Venus.
Venus passed 12°.3 North of Cancer's brightest star Tarf ( Cnc or Beta Cancri, mag. +3.5) on June 28th. The star is positioned at the South-western corner of the constellation's lambda-shaped () figure. The name Tarf, which is not in common usage, is derived from the Arabic Al Tarf meaning 'the End', i.e. the end of the Crab's leg. The name was approved by the IAU in June 2018.
2 0 2 1 July
Between 0430 UT and 19 hours UT on July 3rd Venus passed through the Northern section of the open cluster called Praesepe or The Beehive Cluster (M44 or NGC 2632). Under dark, rural skies it is visible to the naked-eye as a hazy patch of light and in city locations it is easily seen in binoculars (for a fuller description of this cluster, see the Zodiacal Sky: Cancer, Leo and Virgo page). Closest passage took place at around 0850 UT, when Venus was positioned 0°.08 North of the cluster's centre.
On July 4th Venus passed mid-way between the stars Asellus Australis ( Cnc or Delta Cancri, mag. +3.9) and Asellus Borealis ( Cnc or Gamma Cancri, mag. +4.6), which flank Praesepe on its Eastern side. The stars are separated in the night sky by 3º.3, the planet passing fractionally closer to Asellus Borealis at 03 hours UT. Venus passed 7º.0 North of the star Acubens ( Cnc or Alpha Cancri, mag. +4.3), at the South-eastern corner of the constellation, on July 7th.
Situated a short distance away to the ESE of Venus was the planet Mars (mag. +1.8), now close to the end of its 2019-21 apparition, which saw the Red Planet shine at its brightest (mag. -2.4) in the constellation of Pisces in mid-October of the previous year. In early July Venus gained on Mars at a rate of about 0°.5 per day, being 5°.1 WNW of the Red Planet at midnight UT on July 5th, 4°.5 WNW of it on the 6th, 3°.9 WNW of it on the 7th and 3°.3 WNW of it on the 8th. Mars entered the constellation of Leo, the Lion, on July 10th, with Venus trailing just 1°.7 behind it. Venus itself entered Leo on July 11th, when it was just 1°.1 to the North-west of Mars. The waxing crescent Moon swept past, some 3° or 4° North of the pair, on July 12th. At 07 hours UT on July 13th the planets met in conjunction, being separated by 0°.5 (equivalent to one apparent Full Moon diameter). The conjunction was more favourable to Southern hemisphere observers, those at mid-Northern latitudes having to contend with low altitude and summer twilight. Further viewing circumstances of this conjunction are given in the Planetary Conjunctions section below.
Venus in the Western Sky at dusk, photographed by the writer during the planet's evening apparition in January 2009 (click on the thumbnail for the full-size picture, 163 KB). Venus had recently passed greatest elongation and shone at magnitude -4.3.
^ Back to Top of Page
Venus left Mars behind it, and by the time it passed 5°.7 North of the star Subra ( Leo or Omicron Leonis, mag. +3.5), which marks the paw of the Lion's foreleg, on July 15th, the Red Planet was 1°.5 to the West of Venus. Between July 17th and 24th Venus was positioned South of the asterism commonly known as the Sickle of Leo, at the Western end of the Lion, which appears to the naked-eye as a backward question-mark (). Venus passed 8°.5 South of the star Ras Elased Australis ( Leo or Epsilon Leonis, mag. +2.9), at the upper North-western end ('pointed end') of the sickle, on July 17th and 11°.4 South of the star Rasalas ( Leo or Mu Leonis, mag. +3.9), at the top of the sickle, on July 18th.
At the base of the Sickle of Leo (the 'dot' of the backward question-mark) is Leo's brightest star, Regulus ( Leo or Alpha Leonis, mag. +1.3). Venus passed 1º.2 North of the star on July 21st. Regulus is positioned less than 0°.5 North of the ecliptic so it is occasionally occulted by planets and - more frequently - by the Moon. Venus last occulted Regulus in July 1959 and will next occult the star during its morning apparition in October 2044.
On July 24th Venus passed 7°.8 South of the star Algieba (1 Leo or Gamma-1 Leonis, mag. +2.3), at the base of the Lion's neck. It is a double star with golden-yellow components (1 Leo and 2 Leo) of magnitudes +2.3 and +3.6, separated by an angular distance of 4".7. The pair are about 130 light years from Earth and they orbit each other in a period of 554 years. The star is easily split in small telescopes and is considered to be one of the finest double stars in the night sky. An exoplanet was detected orbiting Algieba in 2009, named Gamma-1 Leonis b. Its mass is equivalent to 8.8 Jupiter masses and it orbits the star at a distance of 1.2 AU in a period of 428 days.
2 0 2 1 August
In early August Venus reached magnitude -4.0 and its apparent size reached 13". Telescopes showed a notably gibbous phase, about 80% illuminated. The planet was almost 35° East of the Sun, moving South-eastwards at a steady rate of about 1°.2 per day.
Venus passed 9°.2 South of the star Chertan ( Leo or Theta Leonis, mag. +3.3), at the top of the Lion's rear leg, on August 5th. Prior to IAU standardisation in 2016 the star was also known as Coxa or Chort. At the same moment the planet passed 14°.3 South of the star Zosma ( Leo or Delta Leonis, mag. +2.7), at the rump of the Lion. The planet passed 38' (0°.6) South of the star Leo (Sigma Leonis, mag. +4.0), at the foot of the Lion's hind leg, at around 03 hours UT on August 7th.
Venus entered the constellation of Virgo, the Virgin on August 10th, passing 8' (0º.13) North of the star Zavijava ( Vir or Beta Virginis, mag. +3.6), at the back of the Maiden's head, at 2355 UT on August 13th. Before IAU standardization the star was also known by the names Zavijah, Zavyava or Alaraph.
Venus crossed to the South of the celestial equator (where the declination of a celestial body is 0°) on August 17th, exiting Chart 1 coverage on the following day.
Positioned 21º to the North-west of Venus at midnight UT on August 18th was the planet Mercury (mag. -0.5), now entering the evening sky for its third evening apparition of 2021 and fifth apparition in total (i.e. including morning apparitions). This particular apparition of Mercury favoured Southern hemisphere observers, since from here the ecliptic presented a steep angle to the Western horizon after sunset at this time of year. At 0410 UT on August 19th Mercury and Mars underwent a close conjunction in Leo, separated by just 4'.9 (0º.08). The conjunction was visible at dusk from the Southern hemisphere, low down over the Western horizon. Mars headed out of view over the next week, bringing to an end an apparition which began in October 2019. Mercury, on the other hand, would slowly gain on Venus over the next few weeks, although on this occasion they would not reach conjunction.
On August 20th Venus passed 0º.9 South of the star Zaniah ( Vir or Eta Virginis, mag. +3.8), which is positioned at the rear of the Maiden's head. On August 24th Venus passed 2°.1 North of the star 25 Virginis (mag. +5.8), another star which the planet will occult at a future date - in this case, during its evening apparition in 2026. On August 25th the planet passed 4°.0 North of the star Vir (Chi Virginis, mag. +4.6), which was found to have an exoplanet in 2009. Named Chi Virginis b, the planet is thought to have a mass equivalent to 11 Jupiter masses and orbits Chi Virginis at a distance of 2.1 AU in a period of 835 days. Chi Virginis is currently one of 29 stars in Virgo which have been confirmed to have exoplanets.
Also on August 25th, Venus passed 2º.8 South of the star Porrima ( Vir or Gamma Virginis, mag. +2.8), named after one of the Roman goddesses of prophecy. It is a binary star comprising components of magnitude +3.4 and +3.5, appearing to the naked-eye as a single star of magnitude +2.9. The pair orbit each other in a period of 169 years, their separation varying greatly throughout. They came closest together around 2006, when they were just 0".4 apart, making them difficult to separate in anything but the largest of telescopes. The pair are now widening and are becoming easier to separate in amateur telescopes, being 3".0 apart and aligned North-South in relation to each other. Before IAU standardization Porrima was also known as Arich, a name whose origin appears to be shrouded in mystery.
The paths of Venus, Mercury and Mars through the zodiac constellations during the earlier part of Venus' evening apparition in 2021-22 (click on the thumbnail for the full-size image, 216 KB). The later part of the apparition appears in the star chart above. Planet positions are plotted for 0 hrs Universal Time (UT) at 5-day intervals. For Venus, apparition data for the dates shown in bright white (at 10-day intervals) are included in the table above. A Southern hemisphere version of the chart (South up) is available here (220 KB).
Both evening and morning apparitions of Mercury are included. Wherever a planet was too close to the Sun to view, the path is shown by a dashed line (- -). Hence Mercury's evening apparition drew to a close in late May 2021. It then became lost from view in the evening twilight as it headed towards inferior conjunction with the Sun. The planet re-emerged in the dawn twilight in late June for a morning apparition which lasted through to mid-July. Because Mercury is mostly seen in twilight, many of the fainter stars shown in the planet's vicinity may not have been visible when the planet itself was observed.
The positions at which Mercury attained greatest elongation from the Sun are indicated by the letters 'GE', with the solar elongation angle in brackets; it is Eastern (E) in the evening and Western (W) in the morning (the elongation of Venus is Easterly throughout the chart coverage). The position at which Venus attained greatest brilliancy for this apparition (apparent magnitude = -4.7) is shown by the letters 'GB'. The May evening apparition of Mercury favoured Northern hemisphere observers whilst the morning apparition of late June to July favoured no particular hemisphere.
Planetary conjunctions of Venus with Mercury and Venus with Mars took place on May 29th and July 13th respectively, indicated on the chart by the symbol (for more details see the planetary conjunctions section below).
The faintest stars shown on the chart have an apparent magnitude of about +4.8. Printer-friendly versions of this chart are available for Northern (100 KB) and Southern hemisphere (101 KB) views. Click here (169 KB) to see a 'clean' star map of the area (i.e. without planet paths); a printer-friendly version can be seen here (82 KB). Astronomical co-ordinates of Right Ascension (longitude, measured Eastwards in hrs:mins) and Declination (latitude, measured in degrees North or South of the celestial equator) are marked around the border of the chart.
The two star names shown in yellow-green were officially adopted by the International Astronomical Union (IAU) in 2017.
^ Back to Top of Page
Venus entered Chart 2 coverage on August 24th. On August 26th Mercury (mag. -0.1) entered Virgo, located 17º.6 to the North-west of Venus and gaining on it by about 0º.4 per day. Venus crossed to the South of the ecliptic on August 29th.
2 0 2 1 September
On September 1st Venus passed 2º.1 South of the double star Vir (Theta Virginis, mag. +4.4), located at the base of the Maiden's neck; the planet will occult this star in November 2044. Venus passed 1°.7 North of Virgo's brightest star Spica ( Vir or Alpha Virginis, mag. +1.0) on September 5th.
Mercury, now magnitude +0.0, continued to gain on Venus a little each day in early September, being 16°.1 to the WNW of Venus at midnight UT on the 1st and 15°.6 to the WNW of it on the 4th. The pair came closest together on September 8th, when they were 15°.3 apart; the waxing crescent Moon passed several degrees to the North of the pair from this day to the 10th. Mercury, at magnitude +0.2, reached greatest elongation East (26°.7) on September 14th, positioned 15°.7 to the WNW of Venus.
At 2221 UT on September 15th Venus was positioned at precisely 1.0000 AU from the Earth, i.e. the same distance as the average distance of the Earth from the Sun (149.5 million kms or 92.9 million statute miles). At this point in the apparition the distance between Venus and the Earth was reducing at an average rate of about 1.1 million kms (684,300 statute miles) per day.
On September 16th Venus passed 4°.3 South of the star Kang ( Vir or Kappa Virginis, mag. +4.2), another 'new' name adopted by the IAU over the last few years. In Chinese astronomy Kang was both a constellation and a name given to the second of 28 lunar mansions. On September 17th Venus passed 1°.8 South of the star Khambalia ( Vir or Lamba Virginis, mag. 4.5), which is positioned only 39' (0°.65) from the border with Libra. It is a Coptic name meaning 'crooked-clawed'. Venus entered Libra itself on September 18th.
As Mercury passed to the South of Spica on September 23rd its motion against the background stars of Virgo was slowing, whilst Venus continued steadily South-eastwards at a rate at around 1º.1 per day. Venus passed 2°.2 South of the double star Zubenelgenubi ( Lib or Alpha Librae, mag. +2.8) on September 24th and 5º.9 North of the star Brachium ( Lib or Sigma Librae, mag. +3.3), located at the base of the Scales, on September 27th. Mercury reached its Eastern stationary point on the same day, positioned 2°.2 to the SSE of Spica, by which time it was 23° to the WNW of Venus. Venus and Mercury continued to be seen together in the evening sky through to the end of the month, when Mercury finally headed into the dusk twilight.
Venus passed 11º.0 South of the star Zubeneschamali ( Lib or Beta Librae, mag. +2.5), the Northernmost star of the Scales' quadrilateral figure, on September 30th.
2 0 2 1 October
By early October Venus had brightened to -4.2 and its apparent size had almost reached 20". The planet was around 45º from the Sun and showed a 60% illuminated gibbous phase through telescopes. On October 3rd Venus passed through the aphelion point in its orbit, where it was furthest away from the Sun at 0.7282 AU (108.9 million kms or 67.7 million statute miles).
Throughout October the planet was best seen from mid-Southern latitudes. At 35º South, some 30 minutes after sunset, Venus was placed 38º high in the Western sky, setting in darkness around 4 hours after sundown. In stark contrast, high-Northern latitudes saw the planet set in twilight less than an hour after sunset. Details of the planet's direction and altitude at 30 minutes after sunset for various latitudes are listed in the table below, where they are also shown in the form of a horizon diagram.
On October 4th Venus passed 7°.0 South of the star Zubenelhakrabi ( Lib or Gamma Librae, mag. +3.9), an Arabic name meaning 'the claws of the Scorpion'. The description, of course, refers to what we now know as the constellation of Scorpius, the Scorpion, positioned just to the East of Libra. The figure that we see today as Libra was originally envisioned by both the ancient Greeks and the Arabs as the Scorpion's claws, however the Romans saw the Western group of stars as a Balance held by Astraea, the goddess of Justice.
Venus entered Scorpius on October 7th, passing 47' (0º.8) South of the star Dschubba ( Sco or Delta Scorpii, mag. +2.2) on October 10th and 3°.9 South of the striking double star Acrab (1 Sco or Beta-1 Scorpii, combined mag. +2.6), formerly known as Graffias, on October 11th. Between the hours of 1540 UT and 1840 UT on the same day, Venus passed 3º.0 South of the two Omegan stars Jabhat al Akrab (1 Sco or Omega-1 Scorpii, mag. +3.9) and 2 Sco (Omega-2 Scorpii, mag. +4.3). Together with Dschubba, Acrab and the quadruple star named Jabbah ( Sco or Nu Scorpii, mag. +4.0), they form a distinctive asterism in Northern Scorpius. Venus passed 4º.6 South of Jabbah on the following day (12th).
At around 21 hours UT on October 13th Venus passed 1º.3 South of the eighth-magnitude globular cluster M80 (or NGC 6093) which, like most of the brighter globulars, appears as a faint, circular, fuzzy spot of light through binoculars under dark skies. On the following day (14th) Venus passed 1º.0 North of the variable star named Alniyat ( Sco or Sigma Scorpii, mag. +2.9v).
^ Back to Top of Page
Venus cut across the South-western corner of the large 'non-zodiac' constellation of Ophiuchus, the Serpent Bearer, for a 22-hour period from 07 hours UT on October 15th before re-entering Scorpius on the 16th. Several hours later the planet passed 1º.5 North of Scorpius' brightest star Antares ( Sco or Alpha Scorpii, mag. +1.0v). The star shines with an unmistakable orange-red hue since it is a red supergiant, estimated to measure at least 400 times the diameter of our Sun. It is also a variable star, fluctuating between magnitudes +0.6 to +1.6 over a 5-year period.
On October 18th Venus passed 3º.0 North of the star Paikauhale ( Sco or Tau Scorpii, mag. +2.8), a name which is Hawaii'an for a vagabond. It is another of numerous stars which have been formally assigned 'new' names by the IAU in recent years. On October 21st Venus passed 8º.5 North of the star Larawag ( Sco or Epsilon Scorpii, mag. +2.2), positioned about half-way along the Scorpion's tail. It is an Aboriginal name from the Wardaman culture of Northern Australia, the IAU having approved the name in 2017.
Later on October 21st, Venus entered Ophiuchus. At 0009 UT on the following day (22nd) the distance between the Earth and Venus was the same as that between the Sun and Venus, at 0.7275 AU (108.8 million kms or 67.6 million miles). Seen from far above the Earth's North pole, the Earth, Venus and the Sun now appeared to form an isoscelene triangle in space, with Venus positioned at the apex.
Between the hours of 1845 UT and 2015 UT on October 23rd Venus passed across the seventh-magnitude globular cluster M19 (NGC 6273). At 12' (0º.2) in diameter, it is a roughly oval-shaped 'fuzzball' of stars which can easily be seen through binoculars and small telescopes under fully dark skies. The planet passed 10°.6 South of Sabik ( Oph or Eta Ophiuchi, mag. +2.5), the second brightest star in Ophiuchus, on October 25th.
Positioned 2º.8 East of M19 is the fifth-magnitude star Guniibuu (36 Oph A or 36 Ophiuchi A, mag. +5.1), one of a pair of orange dwarf stars (A and B) which are easily split in small telescopes. Assigned the name by the IAU in 2018, it refers to a mythological robin red-breast in Australian Aboriginal culture. Venus occulted the star at 1445 UT on October 26th, blocking it from view for up to nine minutes. The event was visible in darkness, though unfortunately it was only viewable from the unpopulated Southern Ocean.
By the time Venus passed 1°.7 South of Theta Ophiuchi ( Oph, mag. +3.2), the brightest star in the Southernmost region of Ophiuchus, on October 28th, its apparent motion had slowed to about 1° per day.
Venus reached its greatest elongation from the Sun for this apparition (47°.04 East) at 21 hours UT on October 29th in Southern Ophiuchus, positioned 2°.6 South-east of Theta Ophiuchi. Telescopes now showed Venus' disk half-illuminated (phase = 0.50 or 50%), which is often referred to as the moment of dichotomy. The planet had an apparent diameter of 25" and shone at magnitude -4.3. Although the greatest elongation from the Sun occurred on October 29th, Venus was in fact positioned at precisely 47°.0 elongation for an 11-day period from October 25th through to November 4th. When seen from a point far above the Solar System, the Earth, Venus and the Sun now formed a right-angled triangle in space, with Venus positioned at the 90° angle.
Venus at Dichotomy (click on the thumbnails for their larger versions, 4 KB and 15 KB). (Left) Imaged by Luis A Gómez (Santo Domingo, Dominican Republic) on March 24th 2020 using an 8-inch (203 mm) Schmidt-Cassegrain telescope fitted with a 3x Barlow lens and CMOS camera, and (right) sketched by Volker Heesen (Hamburg, Germany) five days later, using a 120mm/1000mm achromatic refractor telescope at 140x and 200x magnifications. Heesen used yellow (#12) and violet (#47) filters to enhance details in the cloud. Note the 'cusp collars' at the planet's polar regions in Heesen's sketches, which are subtly visible in Gómez' image (Images: ALPO-Japan / Luis A Gómez / Volker Heesen)
^ Back to Top of Page
For a few days around greatest elongation, telescopic observers often attempt to determine the precise date of dichotomy. It is the moment when the terminator (the line separating the light and dark sides of the planet) appears perfectly straight, essentially dividing Venus into two perfect halves. Solar System geometry suggests that this should occur on greatest elongation day, however it often does not and the precise reason for this was not understood until quite recently. Observers often report the straight terminator a few days earlier or later than the greatest elongation date (early in evening apparitions and late in morning apparitions). Hence in the 2021-22 apparition, telescopic observers could have expected to see a 50% phase on or around October 26th. This is commonly known as the phase anomaly or Schröter's Effect (the latter named after the German astronomer Johann Schröter, who first observed the effect in 1793). The phenomenon is thought to be due to Venus' dense atmosphere scattering the sunlight. Blue light scatters more readily than red light (which is why the sky on Earth appears blue) and this effect is also seen on Venus when it is observed using coloured eyepiece filters. The phase anomaly is much more evident when the planet is observed through a blue filter, whilst the anomaly is less evident when seen through filters of other colours, e.g. red or yellow.
For Southern hemisphere observers the date of Venus' maximum solar elongation in 2021 was ideal, since it coincided with the period during which the planet attained its highest position above the local horizon after sunset. On greatest elongation day at latitude 26° South, for example, the planet attained a significant 39°.5 above the Western horizon at 30 minutes after sunset - the highest altitude attained from any latitude during the 2021-22 apparition. Latitudes further South did not fare much worse: at 35° South, for example, Venus was only 1° lower in the same circumstances, whilst at 45° South the planet was only 3° lower in the sky. On this day Venus was visible after sunset for a period of 3¾ hours (at 26° South), 4 hours (at 35° South) and 4¼ hours (at 45° South). In contrast, Northern hemisphere observers saw the planet only 8° above the horizon (at 50° North) and 26° above the horizon (at 20° North), being visible after sunset for 2 hours and 3 hours respectively. The Southern hemisphere advantage on this occasion was the result of Venus' high Southerly declination at this time ( = -26°.9) coinciding with its maximum solar elongation.
For the Southern hemisphere as a whole, the 2021-22 apparition was the best of the five evening apparition 'cycles' of Venus (there being five evening and five morning apparitions in each Venusian 8-year 'cycle'). For Northern hemisphere observers, on the other hand, it was the worst evening apparition in the 'cycle'. But for telescopic observers of the planet, the relatively high placement of Venus in the sky after sunset was of little benefit. Because of the planet's glare when seen against a darkening sky, coupled with the Earth's troublesome atmospheric turbulence at low altitudes, most experienced telescope users observe the planet in full daylight, when it is high above the horizon and more easily seen against a brighter sky. Of course, extreme caution must be taken when attempting to observe any of the planets in daylight and the Sun must be positioned at a safe angular distance from the planet and be fully shielded from view.
Greatest elongation day having passed, Venus began to show a crescent phase through telescopes, its apparent size continuing to enlarge slightly with each passing day. The planet passed 10°.1 North of Shaula ( Sco or Lambda Scorpii, mag. +1.6), positioned at the 'sting' of the Scorpion's tail, on October 30th.
2 0 2 1 November
On November 2nd Venus entered Sagittarius, the Archer, where it would remain through to the end of the apparition.
In early November Venus was best seen from Equatorial latitudes. Here the planet stood 36º high in the South-west at 30 minutes after sunset, being visible for 3¼ hours after sundown. Directions, altitudes and visible durations of the planet at other latitudes in early November can be seen by referring to the table below.
On November 6th Venus attained its most Southerly position in the zodiac for the 2021-22 apparition, at a declination of -27° 14' 31" (-27°.2419 in decimal form), which was the planet's most Southerly declination since October 1930 and before the year 2029. Venus now set at its most Southerly point along the local horizon, an effect which was more pronounced the further away from the Equator an observer was situated. At the Equator (latitude 0°), for example, Venus set in the WSW at this time whilst at 55° North (where the planet was still setting in twilight) it set in the South-west, more than 20° further South along the horizon.
For a period of 17 hours between November 6th and 7th, Venus passed 2º.8 South of the sixth-magnitude gaseous nebula commonly called the Lagoon Nebula or M8 (NGC 6523). With an apparent dimension of 90' by 40', the nebula is visible to the naked-eye from dark sites and is a spectacular sight through larger telescopes - particularly those fitted with nebular filters. The planet's passage South of the nebula began at about 08 hours UT on the 6th and ended at about 01 hours UT on the 7th.
From November 7th through to the 23rd, Venus passed through the so-called Teapot asterism in central Sagittarius. Seen in a North-up orientation, the teapot appears 'tipped up', pouring its contents South-westwards into neighbouring Scorpius. The asterism extends from the star Alnasl ( Sgr or Gamma Sagittarii, mag. +3.0) in the West to the star Tau Sagittarii ( Sgr, mag. +3.3) in the East. The asterism passage got underway on November 7th when Venus passed 3º.2 North of Alnasl, which is positioned at the front of the Archer's bow. Before IAU standardisation the star was commonly known as Nash.
Crescent Venus imaged by Niall MacNeill (Wattle Flat, NSW, Australia) on April 18th 2020 (click on the thumbnail for a largerr image, 3 KB). Venus was 43° from the Sun, 35% illuminated and measured 32".3 across (Image: ALPO-Japan / Niall MacNeill)
^ Back to Top of Page
On November 8th at around 0530 hours UT the waxing crescent Moon passed in front of Venus, blocking it from view, in the planet's second lunar occultation of the apparition. The event was visible in twilight and/or darkness from far Eastern Russia (Sea of Okhotsk, Kamchatka), the South-western Bering Sea and the Western Aleutian Islands. It was technically visible in daylight from Eastern Mongolia, North-eastern China, the Korean peninsula and far South-eastern Russia. Details of the timings and track of visibility can be seen by following the link in the Moon near Venus Dates section below.
On November 10th Venus passed 2°.7 North of Kaus Media ( Sgr or Delta Sagittarii, mag. +2.7), positioned at the centre of the Archer's bow. Before IAU standardisation it was also known by the names Kaus Meridionalis and Kaus Medius.
On November 12th Venus passed 1°.6 South of Kaus Borealis ( Sgr or Lambda Sagittarii, mag. +2.8), positioned at the top of the Teapot asterism. On November 14th the planet passed 3º.0 South of the globular cluster M22 (NGC 6656), which is considered to be one of the finest globulars in the night sky. It has an apparent diameter of 24' and its integrated magnitude (i.e. its apparent magnitude if the cluster were concentrated into a single point) is about +5.9. It is just visible to the naked-eye from dark sites, is easily seen through binoculars and is beautifully resolved in telescopes.
In mid-November Northern Tropical latitudes saw the planet attain its highest altitude after sunset. At latitude 20º North Venus was positioned 28º high in the South-west at 30 minutes after sunset, being visible for around 3 hours after sundown. Meanwhile, higher Northern latitudes were only now beginning to see Venus set in darkness.
Over the next week Venus passed the four stars which form the 'handle' of the Teapot. The planet passed 13' (0°.21) North of Phi Sagittarii ( Sgr, mag. +3.1) at 04 hours UT on November 17th and 11' (0°.18) South of the constellation's second-brightest star Nunki ( Sgr or Sigma Sagittarii, mag. +2.0) at 20 hours UT on November 19th. Venus passed 3°.6 North of Ascella ( Sgr or Zeta Sagittarii, mag. +2.6), at the bottom of the Teapot's handle, on November 22nd. Finally, on November 23rd Venus passed 1°.6 North of Sgr (Tau Sagittarii, mag. +3.3) which marks the Eastern end of the Teapot. The planet passed 4°.9 South of the star Albaldah ( Sgr or Pi Sagittarii, mag. +2.9), positioned at the top of the Archer's head, on November 24th. Venus will occult Albaldah during the planet's morning apparition in 2035.
On November 29th Venus passed 0°.6 South of the star 1 Sgr (Chi-1 Sagittarii, mag. +5.0) which the planet will occult during its evening apparition in 2040. Later that same day the planet passed 3°.2 South of 50 Sagittarii (50 Sgr, mag. +5.6), another star which the planet will occult at a future date, in this case in 2048.
By the end of November Venus' Eastward motion had slowed further to 0º.7 per day.
2 0 2 1 December
Venus continued its way through Sagittarius to the constellation's much fainter Eastern region, passing 0°.6 North of the star 52 Sagittarii (mag. +4.6) on December 4th. At around 14 hours UT on this day the planet attained its greatest brilliancy for this apparition, at magnitude -4.7. Greatest brilliancy occurs when the percentage of the illuminated portion of the disk (phase) and its angular size combine to best visual effect. In 2021 this took place when the planet was 26% illuminated (phase = 0.26), its angular diameter was 41".3 and its solar elongation was 39°. Thirty minutes after sunset, naked-eye observers across the world now saw Venus in its true majestic brilliance against a darkened sky, positioned between 7° (at 60° North) and 32° (at 15° South) above the horizon and being visible for around 2¾ hours after sunset.
In early December observers at mid-Northern latitudes now saw Venus at its best, although the altitudes were somewhat disappointing. Half an hour after sunset at latitude 40º North, the planet was positioned 18º high in the South-west, whilst at 50º North the planet was positioned only 13º high in the SSW. Over the next two weeks, observers at latitude 60º North saw the planet setting in near-darkness for the first time in the apparition.
At 17:25 UT on December 11th a very rare and close conjunction took place, albeit not visible to the naked-eye or binoculars - and technically very difficult to observe in telescopes! A crescent Venus passed just 4' (0°.06) North of the dwarf planet Pluto (mag. +14.4) which had been painstakingly winding its way through Sagittarius since 2007. At the moment of conjunction, Venus was a staggering 36 million times brighter than Pluto, the dwarf planet being 97½ times more distant! This was the closest line-of-sight passage of the two bodies since the year 1525 and before the year 2515. Pluto - whose official status as a true 'planet' was withdrawn by the IAU in 2006 - will leave Sagittarius fully behind it in 2024, when it enters Capricornus, the Sea Goat.
On December 18th Venus' Eastward motion ceased when it reached its Eastern stationary point, some 3º.3 West of the border with Capricornus. Over the coming days the planet began to move retrograde (East to West), its solar elongation reducing more rapidly with each passing day. Venus had also been creeping Northward since late November, carrying it up into North-eastern Sagittarius and slowly improving the visibility of the planet after sunset from Northern latitudes. The planet's setting position also began to drift Northwards along the local horizon over the coming weeks, an effect which was most pronounced at higher Northern hemisphere latitudes. Venus crossed to the North of the ecliptic once more on December 20th.
After a long wait, Venus was now best seen from high-Northern latitudes, although at latitude 60º North it was only a paltry 8º above the SSW horizon at 30 minutes after sunset. The 2021-22 apparition of Venus had not been a good one for observers located at these latitudes; here it had been the worst apparition since that of 2013-14. By contrast, the previous evening apparition of 2019-20 was an excellent one, with Venus positioned high in the Western sky after sunset - the best of the planet's five evening apparitions for Northern hemisphere observers.
From around mid-December, Venus' altitude at any given time after sunset rapidly fell away with each passing day. Observers positioned at the Equator and the Southern Tropical regions saw the greatest fall of altitude per day. From the Equator, on December 18th Venus was placed 21º above the horizon at 30 minutes after sunset, but by December 28th it has fallen to just 8º. Northern hemisphere observers saw a much less dramatic fall: from 50º North at the same period after sunset, the planet was positioned 12º high on the 18th and 8º high on the 28th. These changes in altitude over time are illustrated in the horizon diagrams below where the slope of the planet's apparent path against the local horizon from early December 2021 through to the end of the apparition can be compared across the various latitudes.
Thin Crescentic Venus imaged by Martin R Lewis (St. Albans, UK) on May 29th 2020 using an 8½-inch (222mm) Dobsonian reflector telescope fitted with a CMOS camera (click on the thumbnail for a larger image, 3 KB). The planet was only 8° East of the Sun, 1% illuminated and measured 57".5 across (Image: ALPO-Japan / Martin R Lewis)
^ Back to Top of Page
From around December 26th Mercury (mag. -0.7) emerged into the dusk sky for its final apparition of 2021, which in fact extended into the start of 2022. Mercury and Venus were moving in opposite directions against the background stars of Sagittarius at this time, one entering the dusk sky and the other one leaving it. The orange-pink planet moved swiftly, speeding ENE towards Venus at a rate of 1°.4 per day whilst Venus moved retrograde (towards the WNW) at a more leisurely 0°.4 per day. Mercury was positioned 5°.9 to the South-west of Venus at midnight UT on December 27th and 4°.7 to the SSW of it on the 28th. At 0103 UT on December 29th Mercury (mag. -0.6) sped past Venus (-4.2) at an angular distance of 4°.2 in the third and final planetary conjunction of the 2021-22 apparition. Being only 16° from the Sun, this wide conjunction was visible only between mid-Northern and mid-Southern latitudes. Mercury would continue to be observable in the dusk sky through to mid-January 2022.
As the apparent size of the Venusian crescent continued to enlarge it also became more slender, such that the dark (non-illuminated) side of the planet was well-displayed when seen from the Earth. With the aid of ultraviolet and infrared filters, telescopic observers now began their search for the mysterious and elusive Ashen Light, a faint glowing of the night side of Venus which until recently had no clear explanation. First observed in 1643 by the Italian astronomer Giovanni Riccioli (1598-1671), the effect is best observed when Venus is at a narrow crescent phase and is seen against a fully dark Today, the Ashen Light is considered to be caused either by the planet's surface glowing red hot (due to its extremely high surface temperature) or due to electrical activity insky. its dense atmosphere.
As the apparition neared its end, observers equipped with binoculars may have attempted to detect the tiny crescent of Venus soon after sunset as it languishes low over the WSW sky. Telescopes showed a large, thin crescent at this point, 60" in diameter and just 3% illuminated, the image greatly disturbed by the Earth's turbulent atmosphere and split into the rainbow colours by an effect called dispersion (an example of how dispersion appears through a telescope can be seen here). Observers with exceptionally-good eyesight may have attempted to view the crescent of Venus with the naked-eye. Whilst this may seem extraordinary, the planet's large apparent size brought it very close to the generally-accepted resolution of the human eye, i.e. 1 arcminute (60"). Away from Equatorial latitudes, glare was no longer a problem because Venus was now seen in bright twilight through to its setting, theoretically allowing the crescent to be discerned more easily.
By the third week of December observers at higher Southern latitudes began to have some difficulty viewing Venus as it sank into the bright dusk twilight, setting less than an hour after the Sun. Meanwhile, over the festive season, observers at mid and high Northern latitudes enjoyed views of Venus of between 1½ and 2 hours after sunset, the planet being positioned several degrees above the South-western horizon at dusk. However the duration of the planet's visibility dwindled rapidly in the closing week of December. By the time Venus' solar elongation fell below 15° East on December 30th, it was once again setting in twilight across the inhabited world. After having reached a peak brilliancy of magnitude -4.7 in early December, Venus ended the month at a rather fainter -4.3.
2 0 2 2 January
In the opening days of the new year, Venus became lost from view from all locations as it sped towards inferior conjunction (passing between the Earth and the Sun) on January 9th. At the moment of inferior conjunction, Venus was positioned 4º.8 North of the Sun's centre (ecliptic latitude = +4º.8). After inferior conjunction, the planet swiftly headed into the morning sky. From around mid-January, Venus was seen rising as a 'Morning Star' in the ESE sky shortly before the Sun, heralding a new morning apparition (2022) which lasts through to September of that year.
[Terms in yellow italics are explained in greater detail in an associated article describing planetary movements in the night sky.]
^ Back to Top of Page
Venus Conjunctions with other Planets
Three planetary conjunctions involving Venus took place during the period in question: two with Mercury and one with Mars. The Venus-Mars conjunction of July 13th 2021 was the most visually spectacular of the three, although the Red Planet shone feebly at magnitude +1.8 - about the faintest it can get when seen from Earth. Venus and Mars appeared separated by an angular distance equivalent to that of the Full Moon. The conjunction was viewable from latitudes South of about 45° North. From latitude 40° North the pair were positioned just 9° above the WNW horizon as Mars came into view, being visible for a little less than an hour thereafter. Elsewhere the altitudes and directions of the planetary pair as Mars came into view were as follows: 14° high in the West (at 30° North), 21° high in the WNW (at the Equator) and 18° high in the North-west (at 35° South), the planets being visible for 1¼ hours, 1½ hours and 1¾ hours respectively. Adding to the event was the waxing crescent Moon in the vicinity.
The first conjunction between Venus and Mercury, on May 29th 2021, took place early in the apparition when observers at mid-Southern latitudes had only recently begun to detect Venus in the dusk sky. Taking place at only 16° East of the Sun, the conjunction was best seen around Northern Tropical latitudes; nowhere were the planets seen higher than 12° above the local horizon as the fainter planet (Mercury) came into view. From the Equator the pair were positioned around 11° high in the WNW. Mid-Northern latutudes saw the pair only around 8° high in the WNW whilst mid-Southern latitudes saw them just 6° high in the North-west. In each of these cases the planets set in twilight around 45 minutes after Mercury became visible.
The second Venus-Mercury conjunction, on December 29th 2021, took place late in the apparition when observers were only days away from losing sight of Venus. The narrow solar elongation meant that the planets were seen in twilight throughout from locations North of about 35° North and South of about 40° South. At 4°.2 separation it was a wide passage of the two planets, Mercury speeding past Venus as the latter planet crawled slowly in the opposite direction against the background stars. From latitude 40° North the pair were 7° high in the South-west as Mercury came into view, setting 30 minutes thereafter. Between 30° North and the Southern Tropics they were 8°-10° high in the WSW and visible for around 40 minutes, setting in darkness. At 35° South the pair were only 4° high in the WSW, being visible for less than half an hour and setting in twilight.
The three planetary conjunctions with Venus which were viewable during the 2021-22 apparition are listed in the table below.
Venus conjunctions with other planets during the 2021-22 evening apparition (click on the thumbnail for the full-size table, 24 KB). The column headed 'UT' is the Universal Time (equivalent to GMT) of the conjunction (in hrs : mins). The separation (column 'Sep') is the angular distance between the two planets, measured relative to Venus, e.g. on 2021 Jul 13, Mars was positioned 0°.5 South of Venus at the time shown. The 'Fav. Hem' column shows the Hemisphere in which the conjunction was best observed (Northern, Southern and/or Equatorial). Note that observers located close to the Northern/Southern visibility boundary of any given conjunction will have found it difficult or impossible to observe because of low altitude and/or bright twilight.
In the 'When Visible' column, a distinction is made between Dusk and Evening visibility; the term Dusk refers specifically to the twilight period after sunset, whilst the term Evening refers to the period after darkness falls (some conjunctions take place in darkness, others do not, depending upon latitude). The 'Con' column shows the constellation in which the planets were positioned at the time of the conjunction.
To find the direction in which a conjunction was seen, note down the constellation in which the planets were located ('Con' column) on the required date and find the constellation's setting direction for your particular latitude in the Rise-Set direction table.
The table is excerpted from another showing Venus conjunctions with other planets from 2021 to 2025 on the Venus Conjunctions page.
Although any given conjunction takes place at a particular instant in time, it is worth pointing out that, because of the planets' relatively slow daily motions, such events are interesting to observe for several days both before and after the actual conjunction date.
There are in fact two methods of defining a planetary conjunction date: one is measured in Right Ascension (i.e. perpendicular to the celestial equator) and the other is measured along the ecliptic, which is inclined at 23½° to the Earth's equatorial plane (this is due to the tilt of the Earth's axis in space). An animation showing how conjunction dates are determined by each method can be found on the Jupiter-Uranus 2010-11 triple conjunction page. Although conjunctions measured along the ecliptic can be significantly closer, the Right Ascension method is the more commonly used, and it is the one which is adopted here.
^ Back to Top of Page
Moon near Venus Dates,
May 2021 to January 2022
The Moon is easy to find, and on one or two days in each month, it passes Venus in the sky. Use the following tables to see on which dates the Moon passed near the planet between Mayr 2021 and January 2022:
Moon near Venus dates for the evening apparition of 2021-22 (click on the thumbnail for the full-size table, 30 KB). The Date Range shows the range of dates worldwide (allowing for Time Zone differences across East and West hemispheres). Note that the dates, times and separations at conjunction (i.e. when the two bodies are at the same Right Ascension) are measured from the Earth's centre (geocentric) and not from the Earth's surface (times are Universal Time [UT], equivalent to GMT). The Sep. & Dir. column gives the angular distance (separation) and direction of the planet relative to the Moon, e.g. on July 12th 2021 at 09:08 UT, Venus was positioned 3°.2 South of the Moon's centre.
Because Venus never appears more than 47° from the Sun, the Moon always shows a crescent phase whenever it passes the planet in the sky: a waxing crescent during evening apparitions and a waning crescent during morning apparitions.
On December 1st, 2008 observers in Europe and North-west Africa witnessed the four-day-old Moon passing in front of Venus (in an event called a lunar occultation) around local sunset/dusk (click on the thumbnail for the full-size image, 15 KB). This photograph of the event was taken by the writer from the south-western United Kingdom. Venus had just emerged from behind the Moon after being hidden from view for about 90 minutes. Depending upon the angular size and phase of Venus at the time of any given occultation, it can take anything from several seconds to more than a minute for the planet to become completely obscured by the passing Moon, and the same time to re-appear. This is in contrast to a star, which, being a very distant point of light, disappears behind the Moon more or less instantaneously.
During the same evening, Venus, Jupiter and the crescent Moon formed an impressive celestial grouping in the sky, whose appearance varied somewhat depending upon the observers' location and the time of viewing. The grouping was nicknamed 'the smiley face' conjunction and many photos of the event were taken by the general public worldwide.
The Moon moves relatively quickly against the background stars in an Eastward direction, at about its own angular width (0º.5) each hour (about 12º.2 per day). Because it is relatively close to the Earth, an effect called parallax causes it to appear in a slightly different position (against the background stars) when seen from any two locations on the globe at any given instant; the further apart the locations, the greater the Moon's apparent displacement against the background stars. Therefore, for any given date and time listed in the table, the Moon will have appeared closer to Venus when seen from some locations than others. For this reason, the dates shown in the table should be used only for general guidance.
^ Back to Top of Page
Direction, Altitude & Visibility Duration
of Venus after Sunset,
May to December 2021
The following tables give the direction and altitude (angle above the horizon) of Venus at 30 minutes after sunset, together with the duration of visibility of the planet after sunset, for the 2021-22 evening apparition. An explanation of abbreviations in the tables is given in the box below. For the sake of convenience, the table is split into Northern and Southern hemisphere latitudes (the Equator is included in both tables to allow interpolation of the data for observers situated at Equatorial latitudes). The tables should have proved sufficient to locate the planet in twilight, allowing telescope users to view it in comfort (because of Venus' brilliance, glare becomes a problem when the planet is seen through the eyepiece against a dark sky). Direction and Altitude diagrams are also provided below for intermediate latitudes of 55° North, 35° North, 30° South and the Equator.
The tables allow one to find the highest altitude in the sky which Venus attained for any given latitude during the 2021-22 evening apparition, and in which direction it was seen. For example, observers situated at latitude 30° North would have found the planet highest in the sky (at 30 minutes after sunset) in late November 2021, when it was seen at an altitude of 24° towards the South-west. The duration column shows that the planet was then above the horizon for almost 3 hours after sunset.
Direction & Altitude (30 minutes after local sunset) and Visible Duration of Venus for Northern hemisphere latitudes and the Equator for the evening apparition of 2021-22 (click on the thumbnail for the full-size table, 102 KB). A table for Southern hemisphere latitudes and the Equator can be seen here (94 KB). To find your latitude, visit the Heavens Above website, select your country and enter the name of your nearest town or city in the search box.
The table column headings are as follows:
Dir = compass direction of Venus,
Alt = angular altitude (elevation) of Venus (degrees above the horizon; a negative value of Alt means Venus was below the horizon). Altitudes are accurate to within ±1°.
Dur = the approximate visibility duration of Venus after local sunset (in hrs:mins). An italicised duration means that Venus was seen under twilight conditions through to its setting, i.e. it was not seen against a truly dark sky (twilight in this case refers to nautical twilight, which ends when the Sun is more than 12° below the horizon). Durations are accurate to within ±5 minutes.
Note that the directions and altitudes refer to the planet's position at 30 minutes after local sunset. To find the time of local sunset at your own location, select your country/town from the drop-down menu at the TimeandDate.com website. The approximate time at which Venus set can be found by adding the visibility duration on a particular date (column Dur) to the time of local sunset on the same date. To find the direction in which Venus set on any given date for a particular latitude, note down the constellation in which the planet was located on the required date (column headed Con) then find its setting direction for your latitude in the Rise-Set direction table.
^ Back to Top of Page
Direction & Altitude Diagrams (Horizon Diagrams)
for the 2021-22 Evening Apparition
The following diagrams show an observer's Western horizon (from due South to due North) for latitudes of 55° North (a high-Northern latitude), 35° North (mid-Northern), the Equator and 30° South (mid-Southern). The path of Venus is plotted in the sky at 30 minutes after local sunset throughout the 2021-22 evening apparition with the planet's direction and altitude marked along the horizontal and vertical axes, respectively. Essentially, these diagrams show the same information as in the above look-up tables, but in an illustrative format, for the Equator and three intermediate latitudes.
Below: Paths of Venus in the Evening Sky (30 mins after sunset) for the 2021-22 evening apparition, as seen by observers at latitudes 55° North, 35° North, the Equator and 30° South (click on a thumbnail for a full-size image, ca. 130 KB each). The letters GE refer to the planet's greatest elongation (followed in brackets by its angular distance from the Sun) and the letters GB refer to the planet's greatest brilliance (followed in brackets by its apparent magnitude).
The azimuth (Az, along the bottom of each diagram) is the bearing measured clockwise from True North (where 0° = North, 90° = East, 180° = South, etc.). The altitude (Alt) is the angle measured vertically from the local horizon (the horizon itself is 0° and the point directly overhead is 90°). Azimuth and altitude are co-ordinates which are used for high-accuracy tracking of objects across the sky; in astronomy it is mainly used for setting telescopes which are fitted with altazimuth mounts.
To determine the planet's position in the sky with higher accuracy, an overlay grid is provided for each diagram. The overlay grids are marked at 10° intervals in azimuth and altitude (the dates are removed for clarity). For example, at latitude 30° South on September 1st 2021, at 30 minutes after sunset, Venus was found at azimuth = 279° (i.e. in the West) and altitude = 31°. Azimuths and altitudes are accurate to ±1°.
The Path of Venus in the Evening Sky (plotted for 30 mins after sunset) during 2021-22 for an observer at latitude 55° North. Click here (124 KB) for the overlay grid.
The Path of Venus in the Evening Sky (plotted for 30 mins after sunset) during 2021-22 for an observer at latitude 35° North. Click here (112 KB) for the overlay grid.
The Path of Venus in the Evening Sky (plotted for 30 mins after sunset) during 2021-22 for an observer at the Equator (latitude 0°). Click here (109 KB) for the overlay grid.
The Path of Venus in the Evening Sky (plotted for 30 mins after sunset) during 2021-22 for an observer at latitude 30° South. Click here (97 KB) for the overlay grid.
Although the dates indicated in the above diagrams refer specifically to the period 2021-22, Venus has an 8-year cycle of apparitions such that its position in the evening sky in 2021-22 will repeat very closely in the evening sky of 2029-30. The writer refers to this particular evening apparition as Apparition D; for more details, see the accompanying article describing The Venus 8-year Cycle.
^ Back to Top of Page
Copyright Martin J Powell April 2021
Site hosted by TSOHost