33 episodes

Ian Morison tells you what can be seen in the night sky this month.

The night sky this month Jodrell Bank Observatory

    • Natural Sciences

Ian Morison tells you what can be seen in the night sky this month.

    The night sky for February 2020

    The night sky for February 2020

    Northern HemisphereIan Morison tells us what we can see in the Northern Hemisphere night sky during February 2020.
    The PlanetsJupiter As February begins, Jupiter rises more than 90 minutes before the Sun shining at magnitude of -1.9. During the month it brightens to magnitude -2.0 whilst its angular size increases slightly from 32.5 to 34.1 arc seconds. A low south-eastern horizon will be needed and our views of the giant planet and its Gallilean moons will be hindered by the depth of atmosphere through which it will be observed.

    Saturn passed directly behind the Sun on the 13th of January and, as February begins, will rise less than one hour before the Sun. Then, equipped with binoculars and a very low south-eastern horizon, it might be glimpsed at magnitude +0.58 in the pre-dawn sky - but please do not use binoculars after the Sun has risen. As February progresses, its magnitude actually reduces very slightly to +0.66 as it angular size increases from 15.1 to 15.5 arc seconds. Saturn crosses the Ecliptic (the path of the Sun across the heavens) in a southerly direction on the 13th, just 13 days before Jupiter reaches this point whilst Mars reaches it on the 1st of February. (Stellariun shows them beautifully aligned along the ecliptic this month.)

    Mercury passed in front of the Sun (superior conjunction) on the 10th of January and, on the 10th of February, comes to its greatest elongation east, some 18.2 degrees in angle from the Sun. Mercury starts the month at magnitude -1 and dims to magnitude +0.2 by the 14th and will then soon be lost in the Sun's glare. From the 1st to the 14th, its angular size increases from 5.6 to 8.1 arc seconds but its phase (the % illuminated disk) falls from 85% to just 32% - hence the fall in magnitude. On the 1st of the month, it will set about 70 minutes after the Sun and will have an elevation, low in the west-southwest, of ~9 degrees. This will increase until the 10th before it begins to fall back towards the Sun. Binoculars may well be needed, but please do not use them until after the Sun has set.

    Mars can be seen towards the southeast in the pre-dawn sky at the start of the month. It then rises some three hours before the Sun and will be best seen at around 7am having an elevation of ~8 degrees. It will have a magnitude of +1.4 and a 4.3 arc second, salmon-pink, disk. By month's end it will be seen further round towards the south before dawn and its magnitude will have increased slightly to +1.1. Its angular size will have increased to 5.5 arc seconds but no markings will be seen unless you have access to the Hubble Space Telescope. Lying along the ecliptic it is moving eastwards above the 'Teapot' of Sagittarius and will lie just above its 'lid' on the 24th.

    Venus is now dominating the south-western twilight sky and appears higher each night, climbing from ~29 degrees above the horizon to more than 38 degrees at sunset. During the month its angular size increases from 15.3 to 18.6 arc seconds but, at the same time, it phase (the percentage of the disk illuminated) decreases from 73% to 63% and so the brightness only increases slightly from -4.1 to -4.3 magnitudes.

    HighlightsFebruary: find M31 - The Andromeda Galaxy - and perhaps M33 in Triangulum. In the evenings when the Moon is not prominent, the galaxy M31 in Andromeda will be visible high in the south. There are two ways of finding it:
    1) Find the square of Pegasus. Start at the top left star of the square - Alpha Andromedae - and move two stars to the left and up a bit. Then turn 90 degrees to the right, move up to one reasonably bright star and continue a similar distance in the same direction. You should easily spot M31 with binoculars and, if there is a dark sky, you can even see it with your unaided eye. The photons that are falling on your retina left Andromeda well over two million years ago!
    2) You can also find M31

    • 59 min
    The night sky for January 2020

    The night sky for January 2020

    Northern HemisphereIan Morison tells us what we can see in the Northern Hemisphere night sky during January 2020.
    The PlanetsJupiter passed behind the Sun on December 27th, 2019 and will be lost in the Sun's glare in the early part of January. But, by the middle of the month, it will become visible, shining at magnitude -1.9 in the pre-dawn sky and, by month's end, will rise about an hour before the Sun. A low eastern horizon will be needed and our views of the giant planet and its Gallilean moons will be hindered by the depth of atmosphere through which it will be observed.

    Saturn passes directly behind the Sun on the 13th of January so could not be seen until the very end of the month. Then, equipped with binoculars and a very low eastern horizon, it might be glimpsed at magnitude 0.6 in the pre-dawn sky as it rises about 40 minutes before the Sun - but please do not use binoculars after the Sun has risen.

    Mercury passes in front of the Sun (superior conjunction) on the 10th of January so will not be visible until the very end of the month. Then, at magnitude -1.0, it will set about 70 minutes after the Sun and will have an elevation, low in the west southwest, of ~9 degrees. Binoculars may well be needed, but please do not use them until after the Sun has set.

    Mars can be seen towards the southeast in the pre-dawn sky at the start of the month. It then rises some three hours before the Sun and will be best seen at around 7am having an elevation of ~11 degrees. It will have a magnitude of +1.6 and a 4.3 arc second, salmon-pink, disk. By month's end it will be seen further round towards the south before dawn and its magnitude will have increased slightly to +1.4.

    Venus rises rapidly in the twilight sky this month. As January begins, it could be best seen, shining at magnitude -4, at about 5 pm having an elevation of ~11 degrees above the south-western horizon. As the month progresses, remaining at magnitude -4, its elevation at sunset increases and will be best seen at about 6 pm having an elevation of ~22 degrees. During the month its angular size increases from 13 to 15 arc seconds but, at the same time, it phase (the percentage of the disk illuminated) decreases from 82% to 74% and so the brightness remains constant.

    HighlightsJanuary, evening: the Double Cluster and the 'Demon Star', Algol. January is a good time to look high in the south after dark towards the constellations of Cassiopea and Perseus. Perseus contains two interesting objects; the Double Cluster between the two constellations and Algol the 'Demon Star'. Algol in an eclipsing binary system as seen in the diagram below. Normally the pair has a steady magnitude of 2.2 but every 2.86 days this briefly drops to magnitude 3.4.

    January: find M31 - The Andromeda Galaxy - and perhaps M33 in Triangulum. In the evenings when the Moon is not prominent, the galaxy M31 in Andromeda will be visible high in the south. There are two ways of finding it:
    1) Find the square of Pegasus. Start at the top left star of the square - Alpha Andromedae - and move two stars to the left and up a bit. Then turn 90 degrees to the right, move up to one reasonably bright star and continue a similar distance in the same direction. You should easily spot M31 with binoculars and, if there is a dark sky, you can even see it with your unaided eye. The photons that are falling on your retina left Andromeda well over two million years ago!
    2) You can also find M31 by following the "arrow" made by the three rightmost bright stars of Cassiopeia down to the lower right.
    Around new Moon (24th January) - and away from towns and cities - you may also be able to spot M33, the third largest galaxy after M31 and our own galaxy in our Local Group of galaxies. It is a face on spiral and its surface brightness is pretty low so a dark, transparent sky will be needed to spot it using binoculars (8x40

    • 35 min
    The night sky for December 2019

    The night sky for December 2019

    Northern HemisphereIan Morison tells us what we can see in the Northern Hemisphere night sky during December 2019.
    The PlanetsJupiter, shining on the 1st at magnitude -1.8 and with an angular size of 32 arc seconds, can be seen very low in the southwest as darkness falls at the start of December but, soon after, will be lost in the Sun's glare. Jupiter lies in the southeastern part of Ophiuchus and is heading towards the southernmost part of the ecliptic so, as it appears in the twilight, will only have an elevation of ~6 degrees. With its low elevation, atmospheric dispersion will take its toll and an atmospheric dispersion corrector would greatly help to improve our views of the giant planet and it four Gallilean moons.

    Saturn will be seen west of south as darkness falls at the start of the month. Then, its disk is ~16 arc seconds across and its rings - which are still, at ~24 degrees, nicely tilted from the line of sight - spanning some 36 arc seconds across. During the month its brightness remains +0.6 with an angular size of 15.4 arc seconds. Sadly, now in Sagittarius and lying on the south-eastern side of the milky way, it is at the lowest point of the ecliptic and will only have an elevation of ~12 degrees after sunset. As with Jupiter, an atmospheric dispersion corrector will help improve our view.

    Mercury,. Following its transit of the Sun and reaching greatest elongation west on the 28th of November, can be seen in the pre-dawn sky low in the southeast at the start of December. On the 1st it will have a magnitude +0.29 and will rise around an hour before the Sun. It will then have an elevation of some 9 degrees before being lost in the Sun's glare. With an angular size of ~5 arc seconds, it will then fall back towards the Sun and be lost from view by the middle of the month.

    Mars, Mars can be seen towards the southeast in the pre-dawn sky at the start of its new apparition. It rises some two and a half hours before the Sun at the start of the month and will have an elevation of ~15 degrees before it is lost in the Sun's glare. It then has a magnitude of +1.7 and a 3.9 arc second, salmon-pink, disk. By month's end it will be seen further round towards the south before dawn and its magnitude will have increased slightly to +1.6.

    Venus, Venus may just be glimpsed in the south-west at the start of the month, but will be difficult to see due to the fact that the ecliptic is at a shallow angle to the horizon and so Venus will have a very low elevation. As the month progresses, it will rise higher in the sky and on the 31st will have reached an elevation of 14 degrees as darkness falls. During December, its magnitude remains at about -4 and its disk increases from 11.6 to 13 arc seconds across. A low horizon and possibly binoculars will be needed to spot Venus, but please do not use them until after the Sun has set.

    Highlights November - still a chance to observe Saturn. . Saturn is now low (at an elevation of ~13 degrees) just west of south as darkness falls lying above the 'teapot' of Sagittarius. Held steady, binoculars should enable you to see Saturn's brightest moon, Titan, at magnitude 8.2. A small telescope will show the rings with magnifications of x25 or more and one of 6-8 inches aperture with a magnification of ~x200 coupled with a night of good "seeing" (when the atmosphere is calm) will show Saturn and its beautiful ring system in its full glory.The thing that makes Saturn stand out is, of course, its ring system. The two outermost rings, A and B, are separated by a gap called Cassini's Division which should be visible in a telescope of 4 or more inches aperture if seeing conditions are good. Lying within the B ring, but far less bright and difficult to spot, is the C or Crepe Ring.

    December, late evening: the Double Cluster and the 'Demon Star', Algol. December is a good time to look high in the South

    • 37 min
    The night sky for November 2019

    The night sky for November 2019

    Northern HemisphereIan Morison tells us what we can see in the Northern Hemisphere night sky during November 2019.
    The Night Sky
    Northern Hemisphere
    Ian Morison tells us what we can see in the northern hemisphere’s night sky during November 2019.


    The PlanetsJupiter, shining on the 1st at magnitude -1.9 and falling to -1.8 during the month, can be seen very low in the southwest as darkness falls. As the month progresses, its angular size drops from 33.4 to 32.1 arc seconds - but, by the end of the month, will be lost in the Sun's glare. Jupiter lies in the southeastern part of Ophiuchus and is heading towards the southernmost part of the ecliptic so, as it appears in the twilight, will only have an elevation of ~8 degrees. With its low elevation, atmospheric dispersion will take its toll and an atmospheric dispersion corrector would greatly help to improve our views of the giant planet and it four Gallilean moons.

    Saturn , will be seen just west of south as darkness falls at the start of the month. Then, its disk is ~16 arc seconds across and its rings - which are still, at 25.2 degrees, nicely tilted from the line of sight - spanning some 39 arc seconds across. During the month its brightness remains +0.6 whilst its angular size falls to 15.4 arc seconds. Sadly, now in Sagittarius and lying on the south-western side of the milky way, it is at the lowest point of the ecliptic and will only reach an elevation of ~13 degrees. As with Jupiter, an atmospheric dispersion corrector will help improve our view.

    Mercury, following its transit of the Sun on the 11th - see Highlight below - Mercury rises rapidly into the pre-dawn sky, increasing in brightness by half a magnitude each day and rising about 7 minutes earlier as the days progress. The rates slow until Mercury reaches greatest western elongation some 20 degrees in angle from the Sun on the 28th. By then, it will have brightened to magnitude -0.5 and will rise one and a quarter hours before the Sun. It will then have an elevation of some 11 degrees before being lost in the Sun's glare.

    Mars, which passed behind the Sun (superior conjunction) on September 2nd, can be seen in the pre-dawn sky at the start of its new apparition. It might just be glimpsed just south of east at the start of the month but will then only have an elevation of ~11 degrees at sunrise. Then, binoculars could well be needed to spot its +1.8th magnitude, 3.7 arc second disk - but please do not use them after the Sun has risen. However, by the end of the month, Mars rises some two and a half hours before the Sun remaining at magnitude -2.8 with disk still less than 4 arc seconds across. It will have risen to ~12 degrees elevation before being lost in the Sun's glare.

    Venus, may just be glimpsed in the west south-west setting an hour after the Sun at the start of the month, but will be difficult to see due to the fact that the ecliptic is at a shallow angle to the horizon and so Venus will have a very low elevation. Bymonth's end the Sun sets just before 4 pm and Venus an hour and a quarter later but it will still be hard to spot with an elevation of just 6 degrees as darkness falls. Its magnitude remains at about -3.8 and its, almost fully illuminated disk, ~11 arc seconds across. Binoculars and a very low horizon will be needed to spot Venus, but please do not use them until after the Sun has set.

    Highlights November - still a chance to observe Saturn. Saturn is now low (at an elevation of ~13 degrees) just west of south as darkness falls lying above the 'teapot' of Sagittarius. Held steady, binoculars should enable you to see Saturn's brightest moon, Titan, at magnitude 8.2. A small telescope will show the rings with magnifications of x25 or more and one of 6-8 inches aperture with a magnification of ~x200 coupled with a night of good "seeing" (when the atmosphere is calm) will show Saturn a

    • 29 min
    The night sky for October 2019

    The night sky for October 2019

    Northern HemisphereIan Morison tells us what we can see in the Northern Hemisphere night sky during October 2019.
    The PlanetsJupiter, shining on the 1st at magnitude -2 and falling to -1.9 during the month, can be seen low in the southwest as darkness falls. As the month progresses, its angular size drops from 35.8 to 33.5 arc seconds. Jupiter lies in the southeastern part of Ophiuchus and is heading towards the southernmost part of the ecliptic so, as it appears in the twilight, will only have an elevation of ~10 degrees. With its low elevation, atmospheric dispersion will take its toll and an atmospheric dispersion corrector would greatly help to improve our views of the giant planet.

    Saturn, will be seen in the south as darkness falls at the start of the month. Then, its disk is ~16.8 arc seconds across and its rings - which are still, at 25.2 degrees, nicely tilted from the line of sight - spanning some 41 arc seconds across. During the month its brightness falls from magnitude +0.5 to +0.6 whilst its angular size falls to 16 arc seconds. Sadly, now in Sagittarius and lying on the south-western side of the milky way, it is at the lowest point of the ecliptic and will only reach an elevation of ~14 degrees. As with Jupiter, an atmospheric dispersion corrector will help improve our view.

    Mercury, reaches eastern elongation (at an angular distance of 24.6 degrees) on the 19th of the month but, as the ecliptic is at such a shallow angle at this time of the year, its elevation at sunset (~1.5 degrees) is so low that, lying to the upper left of Venus, it will be very hard to spot. A very low south-western horizon will be needed along with binoculars - but please do not use them until after the Sun has set.

    Mars, which passed behind the Sun (superior conjunction) on September 2nd, returns to the pre-dawn sky at the start of its new apparition. It might just be glimpsed just south of east in the latter part of the month but will only have an elevation of ~11 degrees at sunrise by month's end. Binoculars could well be needed to spot its +1.8th magnitude, 3.7 arc second disk - but please do not use them after the Sun has risen.

    Venus, may be glimpsed in the west south-west some 30 minutes after sunset at the start of the month, but will be very difficult to see due to the fact that the ecliptic is at a shallow angle to the horizon and so Venus will have a very low elevation. By month's end it sets about one hour after the Sun but will still be hard to spot. Its magnitude remains at about -3.9 and its disk, ~10 arc seconds across, is almost fully lit. Binoculars and a very low horizon will be needed, but please do not use them until after the Sun has set.

    HighlightsOctober - observe Saturn. Saturn is now low (at an elevation of ~13 degrees) just west of south as darkness falls lying above the 'teapot' of Sagittarius. Held steady, binoculars should enable you to see Saturn's brightest moon, Titan, at magnitude 8.2. A small telescope will show the rings with magnifications of x25 or more and one of 6-8 inches aperture with a magnification of ~x200 coupled with a night of good "seeing" (when the atmosphere is calm) will show Saturn and its beautiful ring system in its full glory.As Saturn rotates quickly with a day of just 10 and a half hours, its equator bulges slightly and so it appears a little "squashed". Like Jupiter, it does show belts but their colours are muted in comparison.The thing that makes Saturn stand out is, of course, its ring system. The two outermost rings, A and B, are separated by a gap called Cassini's Division which should be visible in a telescope of 4 or more inches aperture if seeing conditions are good. Lying within the B ring, but far less bright and difficult to spot, is the C or Crepe Ring.Due to the orientation of Saturn's rotation axis of 27 degrees with respect to the plane of the solar system,

    • 27 min
    The night sky for September 2019

    The night sky for September 2019

    Northern HemisphereIan Morison tells us what we can see in the Northern Hemisphere night sky during September 2019.
    The PlanetsJupiter, shining on the 1st at magnitude -2.2 and falling to -2 during the month, can be seen in the south as darkness falls. As the month progresses, its angular size drops from 39 to 36 arc seconds. Jupiter, in the southern part of Ophiuchus, ended its retrograde motion on the 11th of August and so is now moving away from Antares in Scorpius initially lying some 7 degrees up and to its left. A highlight gives the times when the Great Red Spot faces the Earth. Sadly it is heading towards the southernmost part of the ecliptic so, as it appears in the twilight, it will only have an elevation of ~13 degrees (from central UK). Happily, its elevation will only have dropped by a degree or so an hour later in full darkness. With its low elevation, atmospheric dispersion will take its toll and an atmospheric dispersion corrector would greatly help to improve our views of the giant planet.

    Saturn , crosses the meridian, so is highest in the sky, at around 9pm BST as September begins. Then, its disk is ~17.6 arc seconds across and its rings - which are still nicely tilted from the line of sight - spanning some 41 arc seconds across. By month's end it will be best seen at around 8 pm BST when lying just west of south. During the month its brightness falls from magnitude +0.3 to +0.5 whilst its angular size falls to 16.9 arc seconds. Sadly, now in Sagittarius and lying on the south-western side of the Milky Way, it is at the lowest point of the ecliptic and will only reach an elevation of ~14 degrees. As with Jupiter, an atmospheric dispersion corrector will help improve our view.

    Mercury, passes behind the Sun (Superior Conjunction) on the night of September 3rd/4th so will not be visible this month.

    Mars, which passes behind the Sun (Superior Conjunction) on September 2nd, lies too close to the Sun to be visible. We will have to wait until the end of October to spot it in the pre-dawn sky at the start of its next apparition.

    Venus, went through superior conjunction on the far side of the Sun on the 14th August. By month's end it will set in the west south-west 30 minutes after sunset but will be very difficult to see due to the fact that the ecliptic is at a shallow angle to the horizon and so Venus will have a very low elevation. Binoculars and a very low horizon will be needed, but please do not use them until after the Sun has set.

    HighlightsSeptember - observe Saturn. Saturn which reached opposition on the 9th of July, is now low (at an elevation of ~14 degrees) in the south as darkness falls lying above the 'teapot' of Sagittarius. Held steady, binoculars should enable you to see Saturn's brightest moon, Titan, at magnitude 8.2. A small telescope will show the rings with magnifications of x25 or more and one of 6-8 inches aperture with a magnification of ~x200 coupled with a night of good "seeing" (when the atmosphere is calm) will show Saturn and its beautiful ring system in its full glory.The thing that makes Saturn stand out is, of course, its ring system. The two outermost rings, A and B, are separated by a gap called Cassini's Division which should be visible in a telescope of 4 or more inches aperture if seeing conditions are good. Lying within the B ring, but far less bright and difficult to spot, is the C or Crepe Ring.

    September - Find the globular cluster in Hercules and spot the "Double-double" in Lyra There are two very nice objects to spot with binoculars in the south-western sky after dark this month. Two thirds of the way up the right hand side of the 4 stars that make up the "keystone" in the constellation Hercules is M13, the best globular cluster visible in the northern sky.Just to the left of the bright star Vega in Lyra is the multiple star system Epsilon Lyrae often called

    • 35 min

Top Podcasts In Natural Sciences

Listeners Also Subscribed To