What comets and asteroids are in the sky tonight?
What comets and asteroids can you see in the sky tonight and over the coming weeks? Find out when and where to look to see a Near Earth Object.
Comets, asteroids and other Near-Earth Objects (NEOs) are a fascinating sight to behold, if you can manage to spot one in the night sky.
Many will remember the appearance of Comet Hale-Bopp in the 1990s, or much more recently, the beautiful sights of Comet NEOWISE and Comet C/2022 E3 ZTF that made headlines around the world and enticed us all to take a look up at the evening sky.
Asteroid Vesta, for example, is one member of the Asteroid Belt that can also be seen, provided you know where and when to look.
But how do you spot comets and asteroids in the night sky? Find out in our guide below which comets and asteroids are visible tonight and over the coming weeks.
For help understanding what our brightness indicators mean, read our guide to stellar magnitude.
If you're a complete beginner, get started with our guide to astronomy for beginners.
April 2023
7 Iris
Minor planet 7 Iris reaches opposition on 30 April, when it will be well-placed within the constellation of Libra, approximately three-fifths of the way along a line from Spica (Alpha (α) Virginis) towards Zubenelgenubi (Alpha (α) Librae).
From the UK, this location gets to an altitude of around 22°, not particularly high, but still enough to give a reasonably clear view.
Iris begins the month just south of a pair of sixth-magnitude stars found by first identifying the mid-point between Zubenelgenubi and Brachium (Sigma (σ) Librae), then extending a line at right angles to the line between both stars from this point for 2.4° westward. The stars are easy to locate with binoculars.
At mag. +10.1, Iris will be too faint to see through average binoculars throughout the month, a small telescope being the minimum equipment needed.
At 00:00 BST (01:00 UT) on 1 April, shining at mag. +10.2, Iris sits half a degree below the star pair mentioned (HIP 72217 and HIP 72310).
It then tracks west-northwest, passing through a fairly barren star-scape, north of Hydra’s tail stars.
It passes a fraction south of mag. +6.6 HIP 70518 on 28 April.
On opposition date, 30 April, Iris brightens to mag. +9.6 and is located adjacent to Libra’s western border with Virgo.
Again, the lack of bright field stars in this part of the sky will make observing this minor planet an interesting spring challenge.
Discovered by the English astronomer John Russell Hind on 13 August 1847, Iris is an S-type (siliceous, stoney) asteroid with a mean diameter of 241 kilometres.
It orbits the Sun between Mars and Jupiter (in the main asteroid belt) varying its distance from the Sun between 1.83 AU and 2.94 AU. It takes 3.7 years to complete each orbit.
March 2023
Ceres
Dwarf planet Ceres reaches opposition on 23 March 2023.
Moving through southern Coma Berenices, Ceres will appear like a seventh-magnitude star throughout March, making it easy to track using binoculars or a small telescope.
On 1 March Ceres shines at mag. +7.3, reaching its peak brightness of +7.1 between 14 and 29 March.
Close to the border between Coma Berenices and Virgo, this is galaxy territory, the dwarf planet tracking along the northern edge of the Virgo Cluster.
At 00:00 UT on 16 March, Ceres lies 40 arcminutes north of the mag. +9.4 galaxy M88.
Later, at 01:00 BST (00:00 UT) on 27 March, it passes across the similarly bright mag. +9.3 galaxy M100 – although instruments that only show the core of this beautiful spiral will more likely show Ceres making a close approach rather than transiting the faint spiral arms.
A good technique to record Ceres is to make a drawing or take a photo of the suspected field over several nights.
Weather permitting, this should reveal Ceres’s movement as it tracks against the background stars.
Facts about dwarf planet Ceres
Ceres was the first identified asteroid. Discovered on 1 January 1801 by Italian monk Giuseppe Piazzi, as the first asteroid it was designated to become 1 Ceres.
In modern times, although it is still referred to in this way, it has been reclassified as a dwarf planet.
Piazzi discovered Ceres by noting the existence of an additional, uncharted star.
Observing over consecutive nights, the ‘star’ appeared to move, raising suspicions that it was something non-stellar.
Illness and bad weather got in the way of further observations until 24 January 1801, when the motion of this mysterious object was sufficient for Piazzi to determine that it was located within the Solar System.
February 2023
Comet C/2022 E3 (ZTF)
Comet C/2022 E3 ZTF is well-positioned at the start of February, high in the sky and theoretically above the threshold for naked-eye visibility.
There are a couple of reasons why this is unlikely to be the case though.
First, the comet is expected to reach a peak magnitude of +4.8 around the end of January and start of February.
Comet magnitudes can be misleading because they refer to how bright the object would look if its light were condensed into a single point like a star.
If the comet has a tangible size, that light is spread out, making its surface dimmer than its rating would suggest.
Secondly, there will be a bright Moon and this will sadly diminish the appearance of C/2022 E3 ZTF.
You can find where the comet will be throughout February in our Comet C/2022 E3 ZTF blog, and as it passes some easy-to-find sky markers, there is a good chance to catch it using binoculars or a small telescope.
C/2022 E3 ZTF was discovered by the Zwicky Transient Facility (ZTF) on 2 March 2022.
The ZTF is a widefield survey setup using an infrared- and visible-light-sensitive camera attached to the 1.22m Samuel Oschin Telescope at the Palomar Observatory in California.
C/2022 E3 ZTF was originally thought to be an asteroid shining at mag. +17.3 when discovered, at a distance 4.3 times further from the Sun than Earth.
It’s a long-period comet with an orbit that takes around 50,000 years to complete.
At the farthest point in its orbit, C/2022 E3 ZTF lies 2,800 AU from the Sun; at its closest it is 1.11 AU, which last occurred on 12 January.
The orbital positions of Earth and the comet mean that C/2022 E3 ZTF will be closest to our planet on 2 February, separated from us by a mere 43 million kilometres (0.29 AU).
January 2023
Comet C/2020 V2 ZTF
With all eyes tuned to comet C/2022 E3 ZTF and its potential rise to naked-eye visibility, it is worth noting that there is another reasonably bright comet visible during January.
Comet C/2020 V2 ZTF starts the month in northern Cepheus, around 7° from Polaris (Alpha (α) Ursae Minoris).
From here, it moves south to pass very close to mag. +2.7 Ruchbah (Delta (δ) Cassiopeiae), ending the month 3° south of this star.
It maintains a fairly constant magnitude, starting the month at +9.3 and ending it at +9.2. That is on the edge of binocular visibility, but a small telescope is probably the best way to go.
C/2020 V2 ZTF passes very close to mag. +5.3 40 Cassiopeiae on the evening of 11 January, a track that then takes it 1° to the west of mag. +5.7 open cluster Collinder 463 in Cassiopeia on the following night (12/13 January). It is a fraction over 0.5° from mag. +4.7 Psi (ψ) Cassiopeiae on the evening of 17 January.
Its southward track takes it into the main W-shaped body of Cassiopeia during the last week of January.
On the night of 23/24 January it passes just west of the mag. +9.6 open cluster NGC 559.
The easiest time to catch the comet will be on the evening of 27/28 January when it passes 15 arcminutes to the west of Ruchbah.
There is a 42%-lit waxing crescent Moon in the sky on this date, but this sets around half-past midnight. Observing after moonset will give the darkest skies and the best chance of seeing the comet.
C/2020 V2 ZTF was discovered by the Zwicky Transient Facility (ZTF) at the start of November 2020 when it appeared at 19th magnitude. The comet reaches perihelion in May 2023.
December 2022
Asteroid 532 Herculina
Asteroid 532 Herculina reaches opposition on 2 December when it will brighten to mag. +10.1 as it moves from Orion into Taurus, where it spends most of December.
As the weeks pass, it only dims by 0.3, ending the month at mag. +10.4.
The good news is that it is particularly easy to identify and gets to a good altitude under the darkness of a winter sky, giving you a great opportunity to track this relatively dim object over the month.
Herculina was discovered in April 1904 by Max Wolf at the Heidelberg-Königstuhl State Observatory.
Wolf was a pioneer of astrophotography and had developed photographic methods to automate the discovery of asteroids.
Wolf himself discovered an impressive 248 asteroids in his lifetime.
Herculina is a large main belt asteroid estimated to be 200km across.
Its precise shape and size are still to be confirmed, but it is believed to be like a battered cube, a shape some have described as resembling a toaster!
Its orbit takes it out as far as 3.26 AU and in as close as 2.29 AU from the Sun, taking 4.62 years to complete.
At favourable oppositions, Herculina shines at mag. +8.8, while at unfavourable ones, it dims down to mag. +12.0.
During December 2022, Herculina can be found travelling between mag. +3.2 Pi3 (≠3) Orionis in a gentle arc taking it west-northwest towards mag. +4.3 Mu (μ) Tauri.
This path is less than 10° to the south of the V-shaped Hyades open cluster, presenting an opportunity to record the cluster and asteroid in a single photograph.
Overlaying and ‘blinking’ a series of photographs will show the movement of 532 Herculina, as well as several other asteroids in the vicinity.
Comet C/2022 E3 ZTF
A treat for Christmas: comet C/2022 E3 ZTF is predicted to be viewable with binoculars, reaching mag. +8.0 on 25 December.
The comet is will be visible inside the semi-circular constellation of Corona Borealis.
November 2022
Asteroid 324 Bamberga
Asteroid 324 Bamberga reaches opposition on 21 November, shining at 9th magnitude in the constellation of Perseus.
It is fortuitously well placed at the moment, the asteroid describing a north-bowing arc between mag. +3.8 Nu (ν) Persei and eclipsing binary Algol (Beta (β) Persei).
324 Bamberga begins the month 20 arcminutes southwest of Nu Persei, thereafter heading west and very gently north, before curving southwest towards the quadrilateral of stars formed by Algol, Omega (ω), Pi (≠) and Rho (ρ) Persei.
More like this
It ends the month a degree east and very slightly south of Algol.
Over this period its brightness hardly varies, starting and ending the month at mag. +9.2, increasing fractionally to +9.1 in the middle of the month.
Despite being the 324th officially recognised asteroid, Bamberga is quite large.
With a mean diameter of 227km, it’s in the top 20 largest asteroids within the main belt.
It also has an eccentric orbit that takes it out as far as 3.59 AU from the Sun and in as close as 1.77 AU.
This creates a considerable variation in its opposition magnitude, reaching mag. +8.0 when conditions are favourable, allowing it to become the brightest of its class
– Bamberga being a C-type, carbon-rich asteroid.
Favourable, near-perihelion oppositions occur with a periodicity of 22 years, and the next is due in 2035 when the asteroid will reach mag. +8.1 in September of that year.
Bamberga rotates once every 29.43 hours, a long period for such a large asteroid.
It’s carbon-rich makeup gives it a low reflectivity of just 6%.
It was discovered by the prolific Austrian asteroid hunter, Johann Palisa in 1892 and is named after Bamberg, a town in southern Germany.
October 2022
Comet C/2022 E3 (ZTF)
As brightening comet C/2017 K2 PanSTARRS has now moved too far south to be followed from the UK, all eyes will be turning to C/2022 E3 (ZTF), a comet currently in Corona Borealis.
Its orbit, combined with the relative motion of Earth, has it performing a south-pointing loop into Serpens Caput before heading north out of the semicircle of stars which forms the distinctive constellation of the Northern Crown.
C/2022 E3 (ZTF) was discovered on 2 March 2022 using a 48-inch telescope at the Zwicky Transient Facility (ZTF) at Mount Palomar Observatory, California.
It’s due to reach perihelion on 13 January 2023 when it will lie 1.11 AU from the Sun.
Its closest approach to Earth is on 2 February 2023, the distance between us and the comet dropping to 0.29 AU or 44 million kilometres.
Its brightness should increase as it approaches perihelion, due to its close proximity to the Sun, and as the distance between us and the comet reduces through to the start of February.
At the start of October, C/2022 E3 is expected to be around mag. +11.7, brightening by one magnitude through the month.
Its location in Corona Borealis means it’s best seen in the evening sky, shifting to the morning sky as we head through November and on towards the end of the year.
At the end of November C/2022 E3 is expected to appear around mag. +9.4, brightening to binocular range at mag. +7.6 by the end of December 2022.
At perihelion on 13 January 2023, the comet is predicted to reach mag. +6.6.
As it performs its closest approach to Earth on 2 February 2023, it’s predicted to be a naked-eye object at mag. +4.8.
Excitingly, it’ll be well positioned for UK observing over this entire period.
September 2022: asteroid 3 Juno
Minor planet 3 Juno reaches opposition on 8 September, a time when it appears to the southwest of the faint, yet surprisingly distinctive, Circlet asterism in Pisces.
On 1 September, 3 Juno is in Pisces, around 5˚ below the midpoint of a line between the Circlet and another famous asterism further to the west, the Water Jar.
Shining at mag. +8.1, Juno crosses the border from Pisces into Aquarius on 3 September.
Juno brightens to mag. +7.8, the same as the planet Neptune, on 7 September, holding this brightness until 9 September after which it slowly begins to dim once more.
By the end of September, Juno will have dimmed to mag. +8.4.
This means it’s a viable binocular target throughout the month, and eminently suitable for tracking through a small telescope.
The comparison in brightness to Neptune is particularly apt as this distant main planet sits about 10˚ to the east of 3 Juno when both worlds share a similar brightness.
The brightest guide star in the area is mag. +3.7 Lambda (λ) Aquarii, Juno appearing around 7˚ to its northeast on 1 September.
It then tracks southwest, appearing 1˚ northwest of Lambda (λ) Aquarii on 21–23 September.
Between 10 and 13 September, 3 Juno appears to cross a roughly 3˚-long, bent line of faint stars formed from mag. +6.7 TYC-5245-586-1, mag. +5.8 TYC-5245-1215-1, mag. +6.3 TYC-5238-1235-1 and mag. +5.8 BU 178.
These provide a good location aid.
Facts about asteroid Juno
Juno is the 11th largest asteroid and the second largest stony (siliceous or S-type) asteroid, with an estimated 1% of the entire mass of the asteroid belt.
Its elliptical orbit is highly eccentric and takes it out to 3.35 AU (Astronomical Units) from the Sun at aphelion and as close as 1.99 AU at perihelion.
The entire orbit takes 4.36 years to complete and is inclined with a tilt of 12˚ to the ecliptic.
August 2022: 4 Vesta
Asteroid 4 Vesta has the potential to appear the brightest of the minor planets, reaching a respectable mag. +5.1 when it’s at a favourable opposition, easily visible to the naked eye from a dark-sky location.
Vesta reaches opposition on 23 August 2022 and although not quite as bright as it can get, it will be on the threshold of naked-eye visibility from a dark sky site at mag. +6.0.
Vesta is currently located in southwest Aquarius, east of Saturn and triangular-shaped Capricornus, tracking in a southwest arc above NGC 7293, the Helix Nebula.
One of the closest planetary nebulae to Earth, the Helix appears large with a very low surface brightness.
Its inner ring is 8x19 arcminutes in size, extending out to appear almost 25 arcminutes across.
Vesta begins August 2022 5º north-northeast of the Helix, ending the month 5º to the west of it.
Use mag. +3.3 Delta (δ) Aquarii as the navigational starting point at the beginning of the month.
Vesta appears as a mag. +6.4 object on 1 August, brightening to its opposition magnitude of +6.0 on 18 August, a value it maintains through to 25 August.
By the end of the month it will have dimmed to mag. +6.2, but is still an easy binocular target.
Vesta was discovered on 29 March 1807 by Wilhelm Olbers, part of the so-called Celestial Police. As its prefix number suggests, it was the fourth minor planet discovered.
It’s a large example, only beaten in size by dwarf planet Ceres.
It completes an orbit of the Sun once every 3.63 years, its orbital path taking it out as far as 2.57 AU and in as close as 2.15 AU.
Interestingly, its size combined with its varying distance from Earth means it presents an angular diameter that varies between 0.2 and 0.7 arcseconds.
July 2022: Asteroids 9 Metis & 14 Irene
9 Metis
Asteroid 9 Metis is a main-belt asteroid, located in a vast band of similar objects orbiting between Mars and Jupiter.
It is a large siliceous or S-type asteroid, a term used to describe a stony or mineralogical composition.
The best-fit size of Metis is a tri-axial ellipsoid 222km x 195km x 140km. It was discovered by Irish astronomer Andrew Graham with a 3-inch, wide-field scope made for hunting comets.
Asteroid 9 Metis reaches opposition on 20 July 2022, having tracked from southern Capricornus at the month’s start into Sagittarius.
This area of sky can be challenging to navigate due to the fact that it never gets very high from the UK.
The start of the track is also less easy to navigate to, thanks to a lack of notable stars in the southeast corner of Capricornus.
The situation does improve throughout July though, thanks in part to darkening skies, but also by virtue of a small kite-shaped pattern – the Little Kite – formed by 58 Omega, 59, 60 and 62 Sagittarii.
These stars range in brightness from mag. +4.5 to mag. +4.7 and thanks to the area being devoid of much else, do tend to stand out.
The asteroid begins the month at mag. +10.1, brightening towards opposition on the 20th, when it shines at mag. +9.7.
By July’s end it only dims by one tenth of a magnitude to end the month at mag. +9.8. This places 9 Metis within small telescope range.
One caveat will be the Moon, which is full on 13 July, making it difficult to navigate this area of sky around mid-month.
On the morning of 14 July, the Moon will sit immediately west of the kite-shaped asterism mentioned earlier.
On opposition night, the Moon will appear 56%-lit, 80˚ to the east, and should be less intrusive, a situation that continues to improve towards July’s end.
14 Irene
Minor planet 14 Irene reaches opposition on 6 July, at the eastern edge of the handle of the Teapot asterism in Sagittarius.
Shining at mag. +9.8, it’ll be tricky to identify Irene’s star-like dot against the backdrop of Milky Way.
June 2022: Comet C/2017 K2 PanSTARRS and asteroid 29 Amphitrite
Comet C/2017 K2 PanSTARRS
Comet C/2017 K2 PanSTARRS is predicted to continue brightening through June and remains well placed for UK observation.
If it follows predictions, it will begin the month with an integrated magnitude of +8.8, making it binocular-friendly.
By the month’s end, it should have brightened to mag. +8.1.
The June solstice occurs on 21 June, representing the period when the night skies are brightest for the year.
For those in the UK’s far north the eternal twilight is obvious, while those in the south fare better in the middle of the night.
This means that although the comet will be brightening over June, so will the sky, only starting to darken subtly by the time the end of the month arrives.
The good news here is that the comet’s brightening will continue beyond June, with it reaching a peak brightness of mag. +7.1 in January 2023.
Unfortunately, the UK will lose sight of K2 PanSTARRS well before then as it tracks ever further south to become a target only visible from the Southern Hemisphere.
In June K2 PanSTARRS is well positioned, starting its track 3˚ to the east of the mag. +3.7 binary star system 72 Ophiuchi.
It then appears to move southwest, clipping the southern edge of IC 4665 on the night of 20/21 June.
It appears close to mag. +2.8 Cebalrai (Beta (β) Ophiuchi) on the nights of 21/22 and 22/23 June, when it is around 8 arcminutes west of the star at 01:00 BST (00:00 UT) on 23 June.
PanSTARRS’s brightness is estimated to be mag. +8.2, but this is also the time when the sky will appear brightest due to the June solstice.
C/2017 K2 PanSTARRS is an Oort Cloud comet with a hyperbolic orbit. Its closest approach to the Sun is on 19 December 2022.
Asteroid 29 Amphitrite
Minor planet 29 Amphitrite reaches opposition on Monday 6 June 2022.
Shining at mag. +9.7, Amphitrite can be found low in Scorpius, the Scorpion in June.
May 2022: 13 Egeria & 18 Melpomene
13 Egeria
Asteroid 13 Egeria reaches opposition on 4 May when it can be found shining at 10th magnitude in Libra, the Scales, less than a degree to the west-southwest of mag. +2.7 Zubenelgenubi (Alpha2 (α2) Librae).
Zubenelgenubi is the name given to the brighter, eastern component of the double star.
The fainter companion, Alpha1 (α1) Librae, shines at mag. +5.2 and is located 3.8 arcminutes to the northwest of Alpha2.
At 01:00 BST (00:00 UT) on 1 May, 13 Egeria is located about 20 arcminutes southwest of Zubenelgenubi, shining at mag. +10.1.
It reaches its peak opposition brightness of mag. +10.0 on 4 May, remaining that bright for a couple of days before dimming again.
By the month’s close, 13 Egeria will have faded to mag. +10.8.
Its monthly track has it heading west, curving and tilted slightly south. It crosses the border from Libra into Virgo on 28 May.
Facts about asteroid 13 Egeria
Egeria was discovered by Annibale de Gasparis on 2 November 1850.
It is a main belt asteroid, taking 4.14 years to complete its orbit around the Sun.
Its orbital distance varies from 2.79 AU at perihelion to 2.36 AU at aphelion, and it spins on its axis once every 7.05 hours.
Egeria was named after a mythological nymph and is a dark object with an albedo of just 8.25%, a figure that indicates how much light is reflected by its surface.
It’s an uncommon type of carbonaceous asteroid known as a G-type, which accounts for just 5 per cent of the asteroid population.
Its occultations of stars have given us details about the asteroid’s physical size.
One such event on 8 January 1992 gave us dimensions of 217km x 196km.
A second opportunity, on 22 January 2008, meant its size could be refined to 214.8km x 192km.
18 Melpomene
Asteroid 18 Melpomene reaches opposition on 5 May. Shining at mag. +10.3, Melpomene is located in northern Libra.
April 2022: Asteroid 8 Flora & Asteroid 10 Hygiea
This month there are several low numbered asteroids reaching opposition, including 8 Flora on 12 April, 15 Eunomia on 16 April and 10 Hygiea on 28 April.
Asteroid 8 Flora
8 Flora, an asteroid, is close to opposition on 12 April.
Technically, opposition occurs when a superior or minor planet has an elongation of 180˚ from the Sun.
However, some objects may not achieve this within a particular year, reaching an elongation of almost 180˚.
On 12 April, Flora’s elongation reaches 170.3˚, which is just shy of a true opposition, but certainly good enough to present the asteroid at its best for the year.
On this date Flora shines at mag. +9.8 in the constellation of Virgo, the Virgin. It’s located near to mag. +3.4 Heze (Zeta (ζ) Virginis) in April.
On the night of 12 April, 8 Flora lies 1˚ north of Heze (Zeta (ζ) Virginis).
During the rest of April, it follows a gently curving track, approximately parallel to the line joining Heze to Auva (Delta (δ) Virginis), its brightness making it a great target for a small scope.
Facts about Asteroid 8 Flora
Flora is a large asteroid. Its mean diameter is 128km, based on tri-axial ellipsoidal dimensions of 136km x 136km x 113km and it has a high albedo of 24.3% (a measure of how much incoming light the asteroid reflects).
At favourable oppositions it can brighten to mag. +7.9, but is also capable of dimming to mag. +11.6. The near-opposition presents Flora at a fairly average brightness.
Asteroid 10 Hygiea
Of the three asteroids on view in April 2022, 10 Hygiea will be the brightest, reaching mag. +9.3 as it sneaks into Virgo, the Virgin having spent much of the month in neighbouring Libra, the Scales.
On 1 April, 10 Hygiea can be seen 5˚ to the southwest of mag. +2.7 Zubenelgenubi (Alpha2 Librae).
Zubenelgenubi is a double star, the mag. +2.7 primary having a mag. +5.2 companion, which is 3.8 arcminutes to the northwest of it.
As the month progresses, Hygiea performs a gently arcing movement to the west-northwest, crossing the border between Libra and Virgo on the night of 22/23 April.
It begins its monthly path at mag. +9.9, brightening to its peak opposition brightness of mag. +9.3 on 25 April, a level it maintains to the month’s end.
Facts about Asteroid 10 Hygiea
10 Hygiea was discovered on 12 April 1849 by Italian astronomer Annibale de Gasparis at the Naples observatory.
It’s a large body located in the main asteroid belt, with dimensions of 450km x 430km x 424km. It’s estimated to contain 3% of the total mass of the main asteroid belt.
10 Hygiea takes 5.57 years to complete one orbit of the Sun at an average distance of 3.1 AU.
As a C-type or carbonaceous asteroid it was once considered for dwarf planet status, mainly by virtue of its nearly round shape, which is close to what you’d expect if it had undergone plastic deformation due to gravity, also known as hydrostatic equilibrium.
It’s now believed that Hygiea’s shape is due to it being a ‘collisional family’ object, a body disrupted by an impact which resulted in fragments coming together to form it.
March 2022: Comet 19P/Borrelly & Asteroid 16 Psyche
Comet 19P/Borrelly
Comet 19P/Borrelly was at its brightest in February 2022, the comet reaching perihelion on 1 February.
At its peak it was expected to reach mag. +8.9, making it a binocular target.
As we head into March, Comet 19P/Borrelly may just remain within binocular range, but it is dimming.
On 1 March, Borrelly shines with a predicted integrated magnitude of mag. +9.5, about 15˚ to the west of the Pleiades open cluster, in the middle of Aries, the Ram.
It’s currently tracking northeast, passing 4˚ to the south of the mag. +3.6 triple star system 41 Arietis on the night of 3/4 March.
By 12 March, Borrelly’s magnitude will have reduced to mag. +10.0. At 00:00 UT on 12th, the comet is about 8˚ to the west-northwest of the Pleiades.
On the nights of 13/14 and 14/15 March, it passes close to the mag. +4.5 TYC 1796-1306-1 in Aries, an orange coloured star.
If Borrelly is showing the greenish hue associated with comets, this should make a nice colour contrast, despite the large difference in brightness between the two.
Closest approach to the Pleiades occurs on the night of 15/16 March, the comet expected to be around mag. +10.1 at this time as it passes 7˚ to the northwest of the cluster.
On 21/22 March, Borrelly will lie about one-third of a degree north of mag. +3.8 Omicron (ο) Persei.
Its northeast track takes it up towards NGC 1499, the California Nebula.
It lies a couple of degrees to the south of the nebula on 26/27 March, moving within one degree of its eastern edge on the 28/29 March, when Borrelly is expected to have faded to around 11th magnitude.
Asteroid 16 Psyche
Asteroid 16 Psyche reaches opposition on 3 March when it can be found shining at mag. +10.4 in the belly of Leo, the Lion.
At 00:00 UT on 1 March, Psyche appears at mag. +10.5 and forms the northeast vertex of an equilateral triangle with mag. +4.6 Chi (χ) Leonis and the mag. +5.0 star 59 Leonis.
It subsequently tracks west-northwest, brightening to mag. +10.4 on 2 March, a level it maintains until 5 March.
It then starts to dim, ending the month at mag. +11.1. At this time, it will be located 1.5˚ east-northeast of variable Rho (ρ) Leonis.
This star exhibits a small brightness variation between mag. +3.8 and mag. +3.9. Psyche’s position at the end of the month places it around 3˚ to the southwest of the galaxy trio M95, M96 and M105.
Facts about asteroid 16 Psyche
Psyche has a diameter of 200km and is thought to be the remnant iron core of a failed planet, a protoplanet.
This is a body that formed out of the Solar System’s original protoplanetary disc and had enough mass to undergo its own internal melting and deformation.
The result is a massive object, Psyche ranking as one of the ten most massive asteroids known.
It’s so massive that its gravitational effect on other asteroids can be used to measure its mass. This has been determined as 2.72 x 1019 kg.
Psyche’s orbit takes 4.99 years to complete, its passage around the Sun taking place at an average distance of 2.9 AU.
It rotates relatively quickly, completing one rotation every 4.2 hours.
It is believed to be potato-shaped, measuring 279km x 232km x 189km.
Its size and shape were partly calculated by compiling the results of over 100 occultation events involving distant stars.
February 2022: Comet C/2019 L3 Atlas and 19P/Borrelly; Asteroid 20 Massalia
Comet C/2019 L3 Atlas
In January 2022 Comet C/2019 L3 Atlas reached perihelion in Gemini, when it appeared at its brightest, hovering about 10th magnitude.
In February 2022, L3 Atlas continues to be well positioned for UK viewing and, if it behaves as predicted, will remain around 10th magnitude, making it an object for larger binoculars and small telescopes.
Discovered by the ATLAS (Asteroid Terrestrial-impact Last Alert System) facility at Haleakala, Hawaii on 10 June 2019, the comet has been a steady performer for many months.
It begins its February track 2˚ north of mag. +3.0 Mebsuta (Epsilon (ε) Geminorum).
From here it tracks into the main shape of western Gemini, the Twins curving south to end the month 2˚ northeast of mag. +4.1 Nu (ν) Geminorum.
This places it near the stars forming the foot of the twin Castor, which is a distinctive area thanks to the presence of open cluster M35.
The cluster is located about 6˚ to the west-northwest of L3 Atlas at the end of February and a mid- or wide-field photograph should capture both objects easily.
Comet 19P/Borrelly
Comet 19P/Borrelly heads northeast through Pisces, the Fishes and into Aries, the Ram in February.
19P/Borrelly reaches perihelion on 2 February, and from the middle of January to 4 February it is expected to appear at mag. +8.0, making it a good target for binoculars and small telescopes.
The comet has been moving northeast and this month it will be favourably located.
At February’s start, it’s positioned south of the narrowing pattern of stars converging on Alrescha (Alpha (α) Piscium). Use mag. +4.9 Mu (μ) Piscium and +4.4 Nu (ν) Piscium to locate it.
19P/Borrelly then tracks northeast, passing Mu Piscium by 0.6˚ on the evening of 3 February and missing mag. +4.3 Omicron (ο) Piscium by 0.5˚ on the evenings of 7 and 8 February.
The comet slips across the border of Pisces and Aries on 9/10 February, and on the evening of 21 February it appears 5˚ northwest of Uranus.
As it continues tracking northeast, it ends the month close to mag. +5.5 Nu (ν) Arietis. At this time 19P/Borrelly lies 7˚ north of Uranus.
19P/Borrelly should appear brightest at February’s start, at mag. +7.9. By mid-month it’s predicted to be mag. +8.1, and it will be down to mag. +8.5 by the month’s close.
Despite its slow decline, these magnitudes are still respectable for a comet and 19P/Borrelly should remain a decent binocular target for the month.
Asteroid 20 Massalia
Asteroid 20 Massalia is a good target with a small telescope throughout February 2022. It reaches opposition in February in Cancer, the Crab.
It’s located near to the border of Cancer and Leo, the Lion on 1 February, 5˚ east-northeast of mag. +4.3 Acubens (Alpha (α) Cancri).
It then tracks west-northwest along a line that takes it to a point about 4˚ southeast of mag. +3.9 Delta (δ) Cancri.
Massalia has an orbit that keeps it within the inner part of the main asteroid belt.
It’s the parent body of a large group of asteroids known as the Massalia family, a collection which has over 6,000 members.
Massalia is an S-type, or stony asteroid, with a mean diameter of 145km. Its orbital period is 3 years 9 months and its mean distance from the Sun is 2.41 AU (361 million kilometres).
When at aphelion, its orbit takes it out as far as 2.75 AU from the Sun, and when at perihelion it moves in as close as 2.07 AU.
Massalia is believed to be nearly spherical in shape, having triaxial ellipsoidal dimensions of 160x145x132km.
It is also believed to have large, flat regions on its surface. Its rotation period is 8.1 hours.
Massalia’s geometric albedo is 21%, a figure that indicates how much incoming sunlight is reflected back from the asteroid’s surface.
This leads to an apparent magnitude that ranges from +8.3 at favourable oppositions to mag. +12.0 at its least favourable oppositions.
February 2022 is favourable, Massalia reaching opposition on 5 February when it appears to shine at mag. +8.5.
On 1 February, Massalia is mag. +8.7, brightening by one-fifth of a magnitude as it reaches opposition. By the month’s end it will have dimmed to mag. +9.3.
January 2022: Comet C/2019 L3 Atlas, Comet 19P/Borrelly
Comet C/2019 L3 Atlas is well placed in January and will be best seen at the start and end of the month when the Moon is absent.
Reaching perihelion on 10 January, Comet C/2019 L3 Atlas is expected to reach mag. +9.7, making it a viable target for larger binoculars or a small telescope.
L3 Atlas was discovered by the ATLAS (Asteroid Terrestrial-impact Last Alert System) facility at Haleakala, Hawaii on 10 June 2019.
Around 18th magnitude, it has brightened since then. It is located in the constellation of Gemini, tracking along the northern edge of the stick figure representing the body of the twin Castor.
In terms of brightness, C/2019 L3 Atlas is expected to stay at mag. +9.7 for the first half of the month, dropping a tenth of a magnitude during the second half.
If the sky is clear and the Moon is out of the way, it should be easy to keep tabs on.
At January’s start, the comet is 3˚ north of mag. +4.4 Tau (τ) Geminorum, midway between mag. +1.9 Castor (Alpha (α) Geminorum) and mag. +3.4 Theta (θ) Geminorum.
It follows a curving path southwest, ending the month 2˚ north of Mebsuta (Epsilon (ε) Geminorum). The full track length over the month is around 10˚.
Slightly brighter than 10th magnitude, L3 Atlas will make a great imaging target for wide-field and close-up study.
C/2019 L3 Atlas isn’t the only bright comet visible this month. 19P Borrelly is moving northeast as it approaches perihelion on 2 February.
Comet 19P/Borrelly is potentially visible using binoculars and should be a great target for small telescopes.
It joins comet C/2019 L3 ATLAS in January’s night sky to produce a great cometary feast.
The comet is currently moving northeast and brightening as it goes.
Starting the month in Cetus, not far from mag. +2.0 Deneb Kaitos (Beta (β) Ceti), the comet remains inside the Cetus boundary for much of the month, managing to slip into Pisces at the end of January.
On the evening of 1 January, 19P sits 5˚ west of Deneb Kaitos, visible after evening twilight has subsided and true darkness has descended, just after 18:00 UT.
This places the comet slightly to the west of south, around 19˚ up as seen from the centre of the UK.
By the month’s end, 19P is predicted to have brightened to mag. +8.9 and, located 3˚ southwest of mag. +4.9 Mu (μ) Piscium on the evening of 31 January, its altitude will have improved too, the comet appearing about 34˚ up as true darkness arrives.
This is despite the region of sky containing Borrelly having naturally drifted further west of south as darkness falls.
We know about Comet 19P/Borrelly thanks to a visit by the Deep Space 1 probe in 2001.
Its nucleus is 8km x 4km x 4km and it follows an elliptical orbit, which takes it out as far as 5.83 AU from the Sun and in as close as 1.35 AU, the distance the comet will be from the Sun at perihelion on 1 February.
It takes Borrelly 6.8 years to make one orbit. Its closest approach to Earth is 55 million km.
Authors
