What’s Up – March 2017

Events of interest for March ….

MARCH – Aurora season is in full swing – from now till around the end of March is the best time for viewing the northern lights here from the UK. Please visit our sister site AUK – Aurora UK for “real time” notifications. Also look out for Nacreous clouds – the high “oil puddle” in the sky  😉

1st March – MOON/MARS – The Moon and Mars will make a close approach, passing within 4°07′ of each other. The Moon will be 3 days old. From Scarborough, the pair will become visible at around 18:00 (GMT) as the dusk sky fades, 31° above your south-western horizon. They will then sink towards the horizon, setting 4 hours and 11 minutes after the Sun at 21:48. The Moon will be at mag -10.6, and Mars at mag 1.3, both in the constellation Pisces. The pair will be too widely separated to fit within the field of view of a telescope, but will be visible to the naked eye or through a pair of binoculars.

3rd March – MOON – The Moon will reach the closest point along its orbit to the Earth and will appear slightly larger than at other times. The Moon’s distance from the Earth varies because its orbit is not perfectly circular – it is instead slightly oval-shaped, tracing out a path called an ellipse. As the Moon traverses this elliptical path around the Earth each month, its distance varies by around 10%, between 363,000 km and 405,000 km. Its angular size also varies by the same factor, and its brightness also changes, though this is hard to detect in practice, given the Moon’s phases are changing at the same time. The exact period of the Moon’s cycle between perigee (closest approach), apogee (furthest recess) and back again is 27.555 days – a period of time called an anomalistic month. This is very close to the Moon’s orbital period (27.322 days), but slightly longer. As the perigee of 3 March 2017 will occur close to the time of new moon, the moon will appear as no more than a thin crescent. On this occasion the Moon will pass within a distance of 369,000 km of the Earth, and appear with an angular diameter of 32.36 arcsec. This may be compared to its average size of 31.07 arcmin.

4th March – 1st QUARTER MOON – The Moon will be prominent in the evening sky, setting around midnight. From Scarborough, it will become visible at around 18:06 (GMT) as the dusk sky fades, 53° above your southern horizon. It will then sink towards the horizon, setting 8 hours and 13 minutes after the Sun at 01:55. At this time in its monthly cycle of phases, it appears almost exactly half illuminated.

12th March – FULL MOON – The Moon will reach full phase. At this time in its monthly cycle of phases, the Moon lies almost directly opposite the Sun in the sky, placing it high above the horizon for much of the night. The sequence of full moons through the year are often assigned names according to the seasons in which they fall. This month’s will be the third to fall in winter 2017 – the Lenten Moon. Over the nights following 12 March, the Moon will rise around an hour later each day, becoming prominent later in the night. Within a few days, it will only be visible in the pre-dawn and early-morning sky. By the time it reaches last quarter, a week after full moon, it will rise at around midnight and set at around noon. At the exact moment when the Moon reaches full phase, it will lie at a declination of +04°44′ in the constellation Leo, and so will appear high in the sky at all but the most extreme latitudes. It will be visible at all latitudes between 84°N and 75°S. Its distance from the Earth will be 388,000 km.

14th March – MOON/JUPITER – The Moon and Jupiter will make a close approach, passing within 2°19′ of each other. The Moon will be 16 days old. From Scarborough, the pair will be visible in the morning sky, becoming accessible at around 21:24, when they rise 7° above your eastern horizon. They will then reach its highest point in the sky at 01:53, 29° above your southern horizon. They will be lost to dawn twilight at around 05:56, 10° above your south-western horizon. The Moon will be at mag -12.5, and Jupiter at mag -2.4, both in the constellation Virgo. The pair will be too widely separated to fit within the field of view of a telescope, but will be visible to the naked eye or through a pair of binoculars.

16th March – VENUS/MERCURY – Venus and Mercury will share the same right ascension, with Venus passing 9°32′ to the north of Mercury. From Scarborough, the pair will be difficult to observe as they will appear no higher than 11° above the horizon. They will become visible at around 18:30 (GMT) as the dusk sky fades, 11° above your western horizon. They will then sink towards the horizon, setting 1 hour and 50 minutes after the Sun at 19:56. Venus will be at mag -4.3, and Mercury at mag -1.4, both in the constellation Pisces. The pair will be too widely separated to fit within the field of view of a telescope or pair of binoculars, but will be visible to the naked eye.

18th March – LAST QUARTER MOON – The Moon will reach the furthest point along its orbit to the Earth and will appear slightly smaller than at other times. The Moon’s distance from the Earth varies because its orbit is not perfectly circular – it is instead slightly oval-shaped, tracing out a path called an ellipse. As the Moon traverses this elliptical path around the Earth each month, its distance varies by around 10%, between 363,000 km and 405,000 km. Its angular size also varies by the same factor, and its brightness also changes, though this is hard to detect in practice, given the Moon’s phases are changing at the same time. The exact period of the Moon’s cycle between perigee (closest approach), apogee (furthest recess) and back again is 27.555 days – a period of time called an anomalistic month. This is very close to the Moon’s orbital period (27.322 days), but slightly longer.  As the apogee of 18 March 2017 will occur when the moon is around last quarter phase, it will appear in the morning sky. On this occasion the Moon will recede to a distance of 404,000 km from the Earth and appear with an angular diameter of 29.52 arcsec. This may be compared to its average size of 31.07 arcmin.

20th March – MARCH EQUINOX –  Today is the March equinox, a day when the Sun is above the horizon for exactly half the time everywhere on Earth. According to the astronomical definitions of the seasons, this day marks the beginning of spring in the northern hemisphere and of autumn in the southern hemisphere. On the day of the equinox, the Sun will appear to rise from the point on the horizon which lies due east, and set beneath the point which lies due west. This happens as the Sun’s annual journey across the sky, through the constellations of the zodiac, carries it across the celestial equator. As a result the Sun appears directly overhead at noon on the Earth’s equator.  Equinoxes occur twice a year – in March and September – once when the Sun is travelling northwards, and once when it is travelling southwards. The position of the Sun at the moment of the March equinox is used to define the zero point of both right ascension and declination. In practice this is not exactly the case, however, because of a phenomenon called the precession of the equinoxes. Over hundreds of years, the direction of the Earth’s spin axis in space changes because it acts like a gyroscope. This means that the location of the equinoxes creep across the sky at a rate of around 50 arcseconds each year. Astronomers quote right ascensions and declinations based on the configuration of the Earth’s path around the Sun on January 1, 2000. Even in the years that have passed since the year 2000, the precession of the equinoxes has moved them by several arcminutes.
Aurora’s are normally very strong around the equinox period as the solar wind speed can often double  !!!

22nd March – SATURN – Saturn at Opposition. The ringed planet will be at its closest approach to Earth. This is the best time to view and photograph Saturn and its moons. Saturn’s rings will be nearly edge-on this year and will be very difficult to see. A medium-sized or larger telescope will allow you to see Saturn’s rings and a few of its brightest moons.

23rd March – COMET – 136472 Makemake will be well placed for observation, in the constellation Coma Berenices. It will be visible for much of the night, reaching its highest point in the sky at around midnight local time. From Scarborough, it will be visible all night. It will become visible at around 19:43 (GMT) as the dusk sky fades, 27° above your eastern horizon. It will be lost to dawn twilight at around 04:29, 41° above your western horizon.

27th March – MERCURY/URANUS – Mercury and Uranus will share the same right ascension, with Mercury passing 2°24′ to the north of Uranus. From Scarborough, the pair will be difficult to observe as they will appear no higher than 9° above the horizon. They will become visible at around 19:49 (GMT) as the dusk sky fades, 9° above your western horizon. They will then sink towards the horizon, setting 1 hour and 36 minutes after the Sun at 20:59. Mercury will be at mag -0.8, and Uranus at mag 5.9, both in the constellation Pisces. The pair will be too widely separated to fit within the field of view of a telescope, but will be visible through a pair of binoculars.

28th March – NEW MOON – The Moon will pass close to the Sun and become lost in the Sun’s glare for a few days. The Moon’s orbital motion carries it around the Earth once every four weeks, and as a result its phases cycle from new moon, through first quarter, full moon and last quarter, back to new moon once every 29.5 days. This motion also means that the Moon travels more than 12° across the sky from one night to the next, causing it to rise and set nearly an hour later each day. Click here for more information about the Moon’s phases. At new moon, the Earth, Moon and Sun all lie in a roughly straight line, with the Moon in the middle, appearing in front of the Sun’s glare. In this configuration, we see almost exactly the opposite half of the Moon to that which is illuminated by the Sun, making it doubly unobservable because the side we see is unilluminated. Over coming days, the Moon will rise and set an hour later each day, becoming visible in the late afternoon and dusk sky as a waxing crescent which sets soon after the Sun. By first quarter, in a week’s time, it will be visible until around midnight.

29th March – MOON/MERCURY – The Moon and Mercury will share the same right ascension, with the Moon passing 6°35′ to the south of Mercury. The Moon will be 1 days old. From Scarborough, the pair will be difficult to observe as they will appear no higher than 12° above the horizon. They will become visible at around 19:51 (GMT) as the dusk sky fades, 12° above your western horizon. They will then sink towards the horizon, setting 1 hour and 57 minutes after the Sun at 21:24. The Moon will be at mag -8.6, and Mercury at mag -0.6, both in the constellation Pisces. The pair will be too widely separated to fit within the field of view of a telescope or pair of binoculars, but will be visible to the naked eye.
After sunset, stargazers should look toward the western sky to see the thin crescent moon forming an impressive celestial triangle with Mercury to its lower right and ruddy Mars above the pair. What makes this event worth watching for, beyond the lovely display, is that the formation will help viewers see Mercury at its brightest and highest in our skies.

Dates highlighted in BOLD are good photographic opportunities

AIUK – Astronomy Imaging UK – https://www.facebook.com/groups/453388178104679/

sister group to ……

AUK – Aurora UK – https://www.facebook.com/groups/AuroraUK/

Note: Times are UK (BST) unless noted differently.

Share

Leave a Reply

Your email address will not be published. Required fields are marked *

Time limit is exhausted. Please reload CAPTCHA.