Above in the Heavens

Moonrise: 08.37am. Moonset: 21.37pm. Phase: Waxing Crescent 13%

The night sky in February 2020

Astronomical darkness:   1st:  18.51  to  05.52       29th:  19.41  to  04.59
Day length,  1st:  08. 55. 41         29th:  10.47.30
Full Moon:  9th at 07.33      New Moon:  23rd at 15.32
Lunar perigee:   10th at 20.22  (360463 km)
Lunar apogee:   26th at 11.36  (406276 km) 

This month’s full Moon is the 4th largest of the year but it may or may not be a Supermoon, depending on which definition you use. Some say that any full Moon near the Lunar perigee, which this one is, qualifies.  Other definitions are any full Moon occurring at a distance of 360,000 km or less, or  those which are 90% or more of the Moon’s maximum size, (a distance of 361,885 km or less).  February’s full Moon, at a distance of 362,472 km, doesn’t meet either of these criteria.
The February full Moon is known as the Snow Moon.  Other names are the Hunger Moon, the Medieval English Storm Moon and the Chinese Budding Moon.

Highlights  (and lows) Venus is shining brightly, a magnificent sight in the evening sky, Mercury has its best evening showing of the year in the second week of the month, but the rest of the naked eye planets are very low in the pre-dawn sky.  Two newly discovered comets are predicted to get no brighter than mag 10 and 15, and we have no meteor showers visible from the Northern Hemisphere.  We do still have a reasonable amount of astronomical darkness – 11 hours at the start of February and about 9 and a quarter at month end.  However, by the end of the month it doesn’t begin until 19.41, well after the start of HPAG meetings.And, if clouds don’t spoil our view of the night sky, the ever increasing number of Starlink satellites will probably manage to do the job.

Orion and Taurus are now above the horizon as the sky darkens but start to set at around 2am at the start of February and soon after midnight by the end of the month. Gemini and Auriga are still prominent, remaining above the horizon until the early hours. Leo, the signpost constellation of Spring, is now high in the sky for most of the night and Bootes, with it’s bright red star Arcturus is rising soon after 11, and around 9 at month end. In the early part of the evening the Plough is low in the North East standing on its ‘handle’, and Cassiopeia high in the North West as darkness falls. By month end, the Summer Triangle will have risen soon after 3am – summer already?  Someone better tell the weather.

Mercury:  in Capricorn, mag -1.0 Starts the month as an evening object, best seen in the second week.  On 1st it is only 6 degrees above the horizon at dusk, setting at 18.03.  It moves into Aquarius on 2nd and by 4th it is at 8 degrees in the SW at 17.15, setting just over an hour later.   Over the next week or so it gets higher in the early evening sky and also brightens.  From 8th to 12th it is at 10 degrees when the sky begins to darken around 17.30.  It reaches greatest eastern elongation on 10th, when it appears 18 degrees from the Sun and is at mag -0.7.  Two days later it is at its highest point, 14 degrees, at sunset, though still down to 10 degrees by the time the sky begins to darken.  It will then be at mag -0.4 and should be visible soon after sunset, to the east of Venus and at about one third the altitude.  Mercury’s position then deteriorates rapidly, by 17th it is down to mag 0.8 and only 6 degrees above the horizon at dusk.  It reaches inferior solar conjunction on 26th and then becomes a morning object, but too close to the Sun to be visible. On 29th it rises half an hour before the Sun but appears separated from it by only 7 degrees.   .

Venus:  in Aquarius, mag -4.1 Unmissable in the evening sky – weather permitting.  On 1st it should be easily visible soon after 17.00, when it is at 25 degrees in the SW.  It moves into Pisces on 3rd and by mid February is 30 degrees above the horizon at around 17.30.  On 27th the 14% Moon passes 6 degrees south of the planet, they are still quite close on the following evening, when the now 21% lit Moon is 12.3 degrees to the SE.   On 29th Venus is easily visible for at least 3 hours.  It’s at 33 degrees in the south at 18.03 in astronomical darkness, setting just after 22.00.  A telescope will show the planet’s gibbous phase – 62% lit at month end.

Mars: in Ophiuchus, mag 1.4A morning object but still very low and not getting much higher in the dawn sky during the month because of its relatively fast eastward motion.  It rises on 1st at 04.53 and only reaches 10 degrees by dawn.  It moves into Sagittarius on 12th when it is slightly higher – 11 degrees as the sky brightens.  On 18th the waning crescent Moon passes 3.2 degrees from the planet just before dawn.  They will be in the same binocular field of view but, as always, TAKE CARE, the Sun rises at 07.20 on this day.   Saturn and Jupiter are also close by around this time.  On 29th Mars rises at 04.31 and reaches 12 degrees by dawn, slightly brighter at mag 1.1.

Jupiter:  in Sagittarius, mag 0.6 Very low in the morning sky.  On 1st it rises at 06.36 but only reaches 4 degrees above the horizon by dawn. On 19th the 17% Moon passes 6 degrees west of the planet soon after it rises at 05.39.  The pair are closest, in daylight, at 19.40.  Because it is so bright it might be possible to spot it in the last few days of the month, from a site with a low, clear SE horizon.  On 29th it rises at 05.06 and reaches 8 degrees by 06.30.

Saturn:  in Sagittarius, mag 0.6 Another morning object, lower and fainter than Jupiter, so very difficult to see this month. On 1st it is still below the horizon when the sky begins to brighten, rising only 40 minutes before the Sun. The thin crescent Moon is close to the planet on the morning of 20th, but the pair are only just above the horizon at dawn. On 29th it rises at 05.32, on this day it forms a line with Mars and Jupiter, very low in the SE just before dawn.

Uranus:  in Aries, mag 5.8
Much better positioned than the 2 gas giants, but even this is now past its best, culminating before the sky is fully dark.  On 1st  it is at 47 degrees in the south as the sky darkens soon after 18.00 and should be high enough for observing until around 22.00, setting at 00.40.  On this evening the Moon passes 7 degrees ESE of the planet at 19.00.  On 28th, at this time, the Moon is 4 degrees to the SE.  It is 32 degrees above the SW horizon,, setting at 22.51.  Uranus should easily be visible in binoculars, maybe even with the naked eye from a dark sky site.

Neptune:  in Aquarius, mag 7.8
Now too low in the evening sky for telescopic observation. On 1st it is only 14 degrees above the horizon at dusk, setting at 20.08.  By 29th it appears 8 degrees from the Sun, setting only 40 minutes after it.

Meteor showersA very poor month for meteor watching.  The only shower, the alpha Centaurids, peaks on Feb 8th with a ZHR of 6. Unfortunately this one is only visible from the southern hemisphere – and the almost full Moon will spoil the view.   Even the Antihelion Source gives a ZHR of less than 2 this month.