Telescope House May 2022 Sky Guide
We begin May under two months from Northern Hemisphere Midsummer - and of course Midwinter for those in the Southern Hemisphere. This begins to have some knock on effects for readers at higher mid-northern latitudes, such as much of Northern Europe and North America. True darkness begins to rapidly diminish, for those at mid-to-high northern latitudes, due to the Earth’s angle of rotation in relation to the plane of our Solar System. For those around 50 degrees latitude N, astronomical dusk begins at just before 11pm on the 1st May and ends at just past 3 in the morning. Fast forward two weeks to the 15th and astronomical dusk begins at 11.46pm and ends at 2.11am. By the end of the month, there is no astronomical dusk and dawn for those at this latitude, as the Sun never sets more than 18 degrees below the horizon - and true astronomical darkness is never achieved. This naturally has a knock-on effect for observation and astrophotography of fainter deep sky targets, but thankfully has no effect on brighter solar system objects.
The Solar System
Our natural satellite begins May in Aries, at New Phase. The following evening the Moon can be found just next to the planet Mercury. Both bodies can be found between the Pleiades and Hyades clusters of stars in Taurus. However, you will need an extraordinarily clear sky and horizon to be able to see the tiny 3.6% illuminated crescent of the Moon before it sets, which occurs at just before 10:45 pm (BST).
Over the next week the Moon will rise steeply up through the zodiacal constellations of Taurus, Gemini, Cancer and into Leo, where it reaches First Quarter phase on the 7th. We are now past the highest of the so-called Evening Spring Crescent phases that we have mentioned before in previous sky guides. Despite this, the first week of May presents us with some great opportunities for observing the Moon at Crescent phase.
The second week of May, find the Moon traversing through the eastern part of Leo, into the expanse of Virgo (the largest constellation in the modern IAU classification of our night sky) and then into Libra. It is here, that the Moon becomes Full during May and also where we have the opportunity to observe the latest Lunar Eclipse.
The eclipse begins its Penumbral phase at around 1:30 am (BST). The Penumbral phase is where the delicate shadow of the Earth’s atmosphere begins to pass over the face of the Moon, in anticipation of the darker Umbral phase, which occurs later when sunlight is completely extinguished by the deeper shadow of our planet. The Umbral phase begins at around 2:30 am (BST) and reaches total phase just under an hour later.
Total lunar eclipses often make the Moon a dusky red colour, similar to the hue that it takes on just before setting. However, other times the Umbral phase can be so deep that the Moon pretty much disappears from view in the sky. This latter event is rare, and often caused by increased pollution in the Earth’s atmosphere – mostly by particles from volcanic eruptions. Naturally, a total lunar eclipse and the lead up to it is a fantastic opportunity for photographic record. A wide field lens can record the entirety of the event from start to finish in multiple exposures, in certain circumstances. Even Smartphone cameras can be used for this sort of eclipse photography. Telescopic photography of the Moon during the eclipse will naturally reveal more detail and higher resolution, but a lunar eclipse can be recorded well using the simplest of gear. We encourage readers to get out there with whatever you’ve got and get some images of the eclipse. Please send us any results you get!
Lunar Eclipse Montage, taken with Explore Scientific 80mm Refractor, as the Moon set, July 2019. Image credit: Kerin Smith
The eclipse will set during the Umbral phase from most of Europe and the West coast of Africa. From the British Isles this happens around 5:30 am (BST). Most of North and South America the Atlantic, and much of the Pacific Ocean will see the eclipse in full from start to finish. No matter where you find yourself it’ll be well worth seeing (even if those of us in Europe will have to brave the small hours of the morning to do so).
The Moon entering Umbral phase, 3am 16th May. Image created with SkySafari 5 for Mac OS X, ©2010-2016 Simulation Curriculum Corp., skysafariastronomy.com.
After the excitement of the eclipse, the Moon spends the next week gliding through the southern part of the Ecliptic, via Scorpius, Ophiuchus, Sagittarius and Capricornus, where it will meet Saturn on the morning of May 22nd, which coincides with Last Quarter phase.
The last week of May finds the Moon catching up with the majority of planets in our solar system, which are currently resident in Pisces. The morning of the 25th find the Moon a little to the south of Jupiter and Mars, the three bodies forming a pretty spectacle in the predawn sky. Two days later on the 27th, the Moon comes into close conjunction with Venus in the morning sky, the two bodies separated by around a degree at their closest.
The month is neatly rounded off with the Moon returning to new phase, joining the Sun in Taurus, on 30th May.
The innermost planet of the Solar System begins May at just past maximum eastern elongation and as such is a decent target for evening observation. However, the planet is now fading and while actually getting closer Earth on its orbit, is rapidly decreasing its phase and illuminated area as it does. The planet can be found at a magnitude of +0.7 in Taurus on the evening of the 1st, which really represents its peak observing potential for this month. At an altitude of over 17° high in the west at sunset, (from 51° north), Mercury is in a very favourable position for observation for those of us in the upper parts of the northern hemisphere. It has often been remarked that Mercury is a difficult planet to find, but the very beginning of May certainly represents the tail end one of the best chances to do this year.
Mercury and the Moon, just after sunset, 2nd May. Image created with SkySafari 5 for Mac OS X, ©2010-2016 Simulation Curriculum Corp., skysafariastronomy.com.
As we’ve often remarked in previous sky guides, nothing remains stationary for Mercury for very long at all. The first three weeks of May finds the planet hurtling sunward, getting progressively fainter and much more challenging to observe as it does. By the time Mercury reaches Inferior Conjunction, between Earth and the Sun, on the 21st of May it will be it will have been invisible to us for some time - lost in the Sun’s glare. After this point Mercury will become a morning object, though it will be significantly further into June before it’s visible again, very low in the sky before sunrise.
As covered in last month's sky guide, the highlight for Venus (and indeed Jupiter) this month is a close conjunction between the two worlds in the morning sky just before sunrise on the 1st. Having the sky’s two most brilliant planets in the same telescopic field of view is a chance few observers would choose to ignore. At barely a third of the degree apart, this should be quite a spectacular sight to both the naked eye and in binoculars and telescopes. While this will require a fairly early morning get up time, we would heartily recommend readers to make plans and enjoy the spectacle - though do be warned, you will need good skies and clear easterly horizons to see the two planets as they will only have risen around 10° high (from 51° north), before the Sun rises. While the two worlds may appear very close together in the sky, they are actually in very different parts of our solar system, and it is just a pure line of sight effect, from our perspective on Earth that brings them together in the sky.
Venus and Jupiter Conjunction, sunrise, 1st May. Image created with SkySafari 5 for Mac OS X, ©2010-2016 Simulation Curriculum Corp., skysafariastronomy.com.
Venus is now past the point of maximum Western elongation, which it reached at the end of March and is now drifting back towards the Sun. This would normally lead to it dropping slightly in altitude from the northern hemisphere’s perspective, as it does so. However, as the Sun is still climbing in the Ecliptic towards mid-summer, Venus actually continues to appear to gain altitude at sunrise from a mid-northern hemisphere perspective, ending the month at just under 12° in altitude (from 51° north), as the Sun rises. While it will be very well placed for observation for sometime to come from the equatorial regions of our planet, Venus is not especially well-situated for us in the northern hemisphere. As such, we must be cautious in our attempts to observe at telescopically, as at low altitude we are looking through much more of the Earth’s atmosphere when we observe a planet. Venus - brilliant though it always is - is no exception to this at present.
Venus ends May at -4.0 magnitude, displaying a 13.7 arc second diameter disc and a gibbous phase of 77% illumination.
Mars starts May as a +0.9 magnitude, 5.8 arc second diameter target in the constellation of Aquarius. Rising about an hour and a half before the Sun, it reaches an altitude of just over 13 1/2° by sunrise (from 51° north).
Unlike nearby Jupiter and Saturn, Mars is not a brilliant target at present, and as such easily overlooked. However, the trend is definitely upwards as far as Mars is concerned - albeit painfully slowly. By mid-month the planet will be +0.8 magnitude and now show a six arc second disc, standing at just under 16° elevation as the Sun rises.
The highlight as far as the Red Planet is concerned, during May, comes at the end of the month, when Mars and Jupiter come into close conjunction with each other. On the mornings of May 29th and May 30th Mars and Jupiter can be found approximately half a degree from each other. This means that they can be observed in the same field of view of a low to medium power telescope. At this point, Mars will be +0.7 magnitude and displaying a 6.4 arc second diameter disc. Contrasted with Jupiter, which at present displays a 37.1 arc second diameter disc, shining at -2.2 magnitude, Mars will be somewhat disappointing in comparison. Still, it will be fun to observe these two very different members of the solar system in the same telescopic field.
Mars and Jupiter, sunrise 29th May 2022. Blue ring demonstrates 30x field of view. Image created with SkySafari 5 for Mac OS X, ©2010-2016 Simulation Curriculum Corp., skysafariastronomy.com.
As previously mentioned, the highlights for Jupiter this month are a couple of very close conjunctions with the planets Venus and Mars, which neatly booking and the beginning and end of May. The beginning of the month finds Jupiter in Pisces, shining at -2.1 magnitude and displaying a 34.8 arc second diameter disc. Rising a little over an hour before the Sun, Jupiter retains an altitude of just over 10° above the horizon as the Sun rises (from 51° north).
Jupiter and Venus, sunrise, 1st May. Blue ring shows 30x telescopic field of view. Image created with SkySafari 5 for Mac OS X, ©2010-2016 Simulation Curriculum Corp., skysafariastronomy.com.
Jupiters position in the sky is not especially favourable for high power telescopic observation during most of the month. Having relatively recently emerged from Superior Conjunction, it is not until the end of May that Jupiter becomes more easy to observe in the morning sky. While it is not especially high in the sky at present, a significant event occurs on May 25 this year, when Jupiter appears to crossover into the northern hemisphere of the sky, for the first time since 2016. While Jupiter will cross back into the southern hemisphere the sky, as it goes retrograde later on in the year (before crossing back into the northern hemisphere in early 2023), this is a significant point in time for observers in the northern hemisphere, as it will have been a good while since Jupiter has been in a more “suitable” area of sky for observation from these parts of the world. This tends to have a massive knock-on effect in terms of quality of views for those observing Jupiter, especially in the higher northern latitudes, and as such is very welcome.
On May 31 Jupiter can still be found in Pisces, having brightened fractionally to -2.2 magnitude, now displaying 37.3 arc second diameter disc and standing just under 21° high in the south-east as the Sun rises (from 51° north).
Saturn begins May in the constellation of Capricornus. Shining at a steady, if unspectacular, +0.9 magnitude, the Ringed Planet is never as prominent as nearby Venus and Jupiter are, but being situated further west in the Ecliptic, rising distinctly earlier, Saturn reaches an elevation of just over 16 1/2° as the Sun rises on the 1st.
By at the end of May Saturn will have brightened a tiny amount to +0.8 magnitude and is now showing a 17.3 arc second diameter disc. A resident in the eastern reaches of Capricornus, it will not be long before the planet goes retrograde in motion - a sure sign of impending Opposition, which will occur in mid-August this year. Saturn can be found at a little below 23° elevation as the Sun rises on 31st (from 51° north)
Saturn and moons, sunrise, 15th May. Image created with SkySafari 5 for Mac OS X, ©2010-2016 Simulation Curriculum Corp., skysafariastronomy.com.
Uranus and Neptune
Both the outer planets are poorly placed for observation during May. Uranus, especially so, as it reaches Superior Conjunction, the opposite side of the Sun from our perspective here on Earth, on May 5th and is thus unobservable during the month.
Neptune is further west in the Ecliptic and can be found on the Pisces/Aquarius borders in the early part of May. However the planet is so faint at +7.9 magnitude, it will be impossible to track down in the dawn sky. This is a pity, because the planet comes into close conjunction with Venus, Jupiter and Mars during the month. But Neptune’s comparative faintness in the glare of the dawn sky will be its undoing from an observational point of view. We must bide our time as far as observing both of these outer worlds goes.
Uranus at Superior Conjunction, 5th May. Image created with SkySafari 5 for Mac OS X, ©2010-2016 Simulation Curriculum Corp., skysafariastronomy.com.
There are no reasonably bright comets to observe this month. The comet C/2019 L3 Atlas is probably our best bet for observing during May. It is an evening object during the month, moving through the southern part of Gemini and into Canis Minor, though will be far from bright.
C/2019 L3 Atlas path May 2022 (comet position shown 1st May). Image created with SkySafari 5 for Mac OS X, ©2010-2016 Simulation Curriculum Corp., skysafariastronomy.com.
Continuing observations of Comet 2017/K2 (PanSTARRS) suggest it is still brightening relatively rapidly, but it is still around the 10th magnitude at best presently. The comet may however become brighter from August of this year, but is unlikely to get any brighter than 7th or 8th magnitude, making it very much one for telescopic or large binocular observations.
Reaching their upper range of activity between the 4th-6th May, the Eta Aquariids meteor shower peaks on the night of May 5th this year. While the zenith hourly rate of this shower - around 30-40 at maximum, this year - is not as high as some of the major annual showers, this event is worth staying up for (or attempting to record photographically), as the Moon, the perennial menace of meteor shower observation, will be at narrow crescent phase and will have set in the evening, long before the radiant of the shower rises. As meteors from any radiant can be seen in any part of the sky, observers do not have to solely concentrate on the part of the sky the radiant is located in to catch some decent meteor activity. However, as the radiant rises so late, it is often commented that the Eta Aquarius are better seen in the southern hemisphere, but those in the northern hemisphere should still try and catch a few meteors, if possible. This shower is seeded by the famous Halley’s Comet, whose debris is quite fast-moving, resulting in bright, energetic meteors. The best of these will be visible, even from relatively light polluted environments, though naturally, the darker your observing site, the better, as far as all meteor observations are concerned.
Eta Aquariids meteor shower radiant rising, early morning, 5th May. Image created with SkySafari 5 for Mac OS X, ©2010-2016 Simulation Curriculum Corp., skysafariastronomy.com.