The Night Sky This Month

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Ian Morison tells you what can be seen in the night sky this month.
Updated: 22 hours 10 min ago

The night sky for May 2018

Wed, 16/05/2018 - 12:00
Northern Hemisphere

Ian Morison tells us what we can see in the Northern Hemisphere night sky during May 2018.

The Planets

  • Jupiter - Jupiter reaches opposition on May 8th, so will be visible all night. It shines at magnitude -2.5 and has a disk some 44 arc seconds across throughout the month. Jupiter's equatorisl bands and sometimes the Great Red Spot (see 'highlights' for the times when it crosses Jupiter's central meridian) and up to four of its Gallilean moons will be visible in a small telescope. Sadly, lying in Libra during the month, Jupiter is heading towards the southern part of the ecliptic and will only have an elevation of ~20 degrees when crossing the meridian. Atmospheric dispersion will thus hinder our view and it might be worth considering purchasing the ZWO Atmospheric Dispersion Corrector to counteract its effects.

  • Saturn - Saturn, now well into its new apparition, rises at around midnight on the first of May and a couple of hours earlier by month's end. With an angular size of ~17.5 arc seconds (increasing to 18.1 during the month) it climbs higher before dawn and so becomes easier to spot as the month progresses. Its brightness increases from +0.4 to +0.2 magnitudes during the month. The rings were at their widest some months ago and are still, at 25 degrees to the line of sight, well open and spanning ~2.5 times the size of Saturn's globe. Saturn, lying in Sagittarius, is close to the topmost star of the 'teapot'. It will been seen best just before dawn but, sadly, even when at opposition later in the year it will only reach an elevation of just over 15 degrees above the horizon when crossing the meridian. Atmospheric dispersion will thus greatly hinder our view and, as for Jupiter, it might be worth considering purchasing the ZWO Atmospheric Dispersion Corrector to counteract its effects.

  • Mercury - Mercury reached greatest elongation east from the Sun on April 29th and might just be glimpsed low above the western horizon for the first few days of May, but for the remainder of the month will lie too close to the Sun to be visible.

  • Mars - Mars starts the month in Sagittarius and moves into Capricornus in mid-May. Now a morning object, it rises at around 1:30 am BST at the start of the month and a little after midnight by May 31st. During the month, Mars has a magnitude which increases rapidly from -0.4 to -1.2 and has an angular size of 11.1 increasing to 15.1 arc seconds during the month so it should be possible to spot details, such as Syrtis Major, on its salmon-pink surface with a small telescope. It will only reach an elevation of ~10 degrees before dawn at the start of the month and ~131 degrees by month's end. Sadly, the atmosphere will hinder our view. Another reason for purchasing a ZWO Atmospheric Dispersion corrector?

  • Venus - Venus, seen in the west after sunset, shines brightly at magnitude -3.9 all month with an angular size of 11.5 increasing to 13 arc seconds. Venus rises a little higher in the sky as April progresses, initially setting around two hours after the Sun but increasing to two and a half hours by month's end as its elevation at sunset stays at around 20 degrees - it will be very prominent in the evening sky. Venus starts the month in Taurus, not far above the Hyades Cluster, but passes into Gemini on the 19th before passing between the Hyades and Pleiades Clusters on the 27th.

  • Highlights
  • May - a great month to view Jupiter. This is a great month to observe Jupiter which comes into opposition on May 8th and will be visible during all the hours of darkness. It is moving down the ecliptic and now lies in Libra and, sadly, will only reach an elevations of ~20 degrees when crossing the meridian. An interesting observation is that the Great Red Spot appears to be diminishing in size. At the beginning of the last century it spanned 40,000 km across but now appears to be only ~16,500 km across - less than half the size. It used to be said that 3 Earths could fit within it, but now it is only one. The shrinking rate appears to be accelerating and observations indicate that it is now reducing in size by ~580 miles per year. Will it eventually disappear?

  • The features seen in the Jovian atmosphere have been changing quite significantly over the last few years - for a while the South Equatorial Belt vanished completely (as seen in Damian's image) but has now returned to its normal wide state.

  • May: Look for the Great Red Spot on Jupiter. This list gives some of the best evening times during May to observe the Great Red Spot which should then lie on the central meridian of the planet. The times are in UT.

  • May 5th and 6th before dawn: The Eta Aquarid Meteor Shower. The Eta Aquarids are one of the finest meteor showers that can be seen from the southern hemisphere but, in the northern hemisphere, may only be glimpsed in the pre-dawn sky in the south-east around 90 minutes before dawn. Sadly, this year the peak is when there is a waning gibbous Moon in the sky - so moonlight will hinder our view.

  • May 5th - before dawn: Saturn, the Moon and Mars together in the southern sky. Before dawn on the 5th of May and given a clear sky and a low horizon to the east of south, you should be able to spot Saturn to the right of the waning gibbous Moon with Mars down to its lower left. Binoculars might be needed to penetrate the sky's pre-dawn brightness, but please do not use them after the Sun has risen.

  • May 17th after sunset: Venus above a very thin crescent Moon. If clear after sunset on the 17th May and given a very low western horizon you should easily spot Venus! However it will be much harder to spot a very thin crescent Moon, just two days after new, down to its lower left. Binoculars may well be needed to see the Moon, but please do not use them until after the Sun has set.

  • May 6th and 22nd - evenings: The Hyginus Rille. These evenings, should it be clear, are a superb time to view the Hyginus Crator and Rille as it will lie close to the terminator. For some time a debate raged as to whether the craters on the Moon were caused by impacts or volcanic activity. We now know that virtually all were caused by impact, but it is thought that the Hyginus crater that lies at the centre of the Hyginus Rille may well be volcanic in origin. It is an 11 km wide rimless pit - in contrast to impact craters which have raised rims - and its close association with the rille of the same name associates it with internal lunar events. It can quite easily be seen to be surrounded by dark material. It is thought that an explosive release of dust and gas created a vacant space below so that the overlying surface collapsed into it so forming the crater. The author's image of the crater and rille can be seen in the inset to the image of the 8 day old Moon below.

Gabriela Perez from the Carter Observatory in New Zealand speaks about the Southern Hemisphere night sky during May 2018.

  • Introduction - Kia Ora, Gabriela Perez here from Wellington New Zealand. It's autumn here in the southern hemisphere and we can tell from the chilly night and fallen leaves but also from our skies. We can see the summer months sinking into the Western horizon with Orion and his companions making way for all our winter constellations. Quite a nice time year to see Orion and Scorpius on either sides of the sky knowing that they're doomed to chase one another forever.

  • Orion - The best time to view the deep space objects will be around the middle of the month as new moon will be on the 15th of May and on the 29th we will round off the month with the full moon.

  • The Planets - In the middle of May we will have sliver Venus setting 90 minutes after the Sun in the northwest once again becoming our evening star. The fainter planets, Saturn and Mars will also be in the sky in the constellation of Sagittarius.

  • Scorpius - Another fantastic sight in the constellation of Scorpius is the Bug/Butterfly Nebula. It is a bipolar planetary nebula, having one the most complex structures ever seen with a star at its centre, also in its final stages but burning at some of the hottest temperatures recorded in the galaxy (for a star).

  • Stellar Clusters - Between Scorpius and Sagittarius is the zone designated Sagittarius A and it is our galactic centre. The middle point of our Milky Way or the 'bulge' making up some of the brightest and star-rich regions of our night sky. We have noted some intense radio feedback form this zone as astronomers believe that in the centre of our galaxy (and in fact the centre of every galaxy) is a supermassive black hole holding it together. On a clear night you can follow the Milky Way up to the Crux constellation or the Southern Cross, the smallest constellation but arguably the most well-known in the South. Use the pointer stars, the reddish orange Alpha Centauri and the blue/white Beta Centauri to make sure you have the right cross shape in the sky. Nearby star clusters such as the Jewel Box cluster or the Southern Pleiades make for some stunning telescope observations. Pick out the different colours in the cluster depicting stars of different sizes and at different stages of their lives. For a little bit of a challenge, and for another look at a dying star, you can move towards the constellation of Carina and find Eta Carinae and the Carina Nebula.

  • Meteor Shower - If you're up late enough, at about around midnight on the 6th till the early hours of the 7th of May you can catch the peak of the Eta Aquarids. This spectacular annual meteor shower is capable of producing up to 60 meteors per hour. They will radiate from Aquarius but can be seen in a lot of the night sky.

  • Arcturus - And if you're up early enough soon after dusk Arcturus appears in the northeast, seen twinkling as it is close to the horizon with it's light being broken up. It is the brightest red object in the sky, only outshone by Mars and 120 times brighter than the Sun.

  • That's all for me for this month in the South and remember to keep warm but not let that stop you from going outside and looking up!

The night sky for April 2018

Sun, 01/04/2018 - 00:00
Northern Hemisphere

Fiona Healy tells us what we can see in the Northern Hemisphere night sky during April 2018.

Fiona Healy and Fiona Healy from the Carter Observatory in New Zealand speak about the Southern Hemisphere night sky during April 2018.

We would have descriptions here, but unfortunately Fiona's cat has run off with them and none of us are brave enough to try and get them back.

The night sky for March 2018

Thu, 01/03/2018 - 16:00
Northern Hemisphere

Ian Morison tells us what we can see in the Northern Hemisphere night sky during March 2018.

  • Jupiter.Jupiter rises just before midnight at the beginning of the month and about one hour earlier by month's end. Initially it has a 39 arc second disk, shining at a magnitude of -2.2 but as the month progresses, its apparent diameter increases to 42.5 arc seconds and it brightens to magnitude -2.4. Jupiter will transit before dawn and so will enable the giant planet to be seen with the equatorial bands, sometimes the Great (but reducing in size) Red Spot and up to four of its Gallilean moons visible in a small telescope. Sadly, Jupiter, lying in Libra during the month, is heading towards the southern part of the ecliptic and will only have an elevation of ~20 degrees when crossing the meridian. Atmospheric dispersion will thus hinder our view and it might be worth considering purchasing the ZWO Atmospheric Dispersion Corrector to counteract its effects.

  • Saturn.Saturn, at the start of its new apparition, rises at around 3 am at the start of the month and just after 2 am at its end. With an angular size of ~16.3 arc seconds it climbs higher before dawn and so becomes easier to spot as the month progresses. Its brightness increases from +0.6 to +0.5 magnitudes during the month. The rings were at their widest a few months ago and are still, at 26 degrees to the line of sight, well open. Saturn, lying in Sagittarius, is just 3 degrees above the topmost star of the 'teapot'. Sadly, even when at opposition later in the year it will only reach an elevation of just over 15 degrees above the horizon when crossing the meridian. Atmospheric dispersion will thus greatly hinder our view and it might be worth considering purchasing the ZWO Atmospheric Dispersion Corrector to counteract its effects.

  • Mercury.Mercury gives us its best evening apparition this month when it reaches its peak height above the western horizon on March 15th when, at greatest elongation, it lies some 18 degrees west of the Sun. However, by this time its magnitude has dropped from -1.3 at the beginning of March to -0.4 magnitudes. Its magnitude continues to fall, dropping to +0.9 by 20th and soon after will be lost in the Sun's glare. Mercury flirts with Venus during the month as detailed in the highlights.

  • Mars.Mars starts the month moving quicky eastwards in Ophiuchus moving into Sagittarius on the 12th of the month as it moves towards Saturn. Now a morning object, it rises at around 2 am at the start of the month. During the month, Mars has a magnitude which increases from +0.8 to +0.3 and an angular size of just 7, increasing to 8.5, arc seconds so it will be hard to spot details on its salmon-pink surface. It will only reach an elevation of ~14 degrees before dawn at the start of the month and just 12 degrees by month's end.

  • Venus. Venus, seen low in the west after sunset shines at magnitude -3.9 all month with an angular size of ~10.3 arc seconds. Venus rises a little higher in the sky as March progresses, initially setting around one hour after the Sun but increasing to an hour and a half by month's end. It has two near conjunctions with Mercury as described in the highlights above.

  • Highlights
  • March 2nd to 4th after sunset: Venus and Mercury within 1.3 degrees of each other.After sunset on these three evenings and given a clear sky and a low western horizon, you should be able to spot Venus and Mercury. Their closest is on the 3rd when they are just 1.1 degrees apart. Binoculars might be needed to penetrate the skys residual brightness, but please do not use them until after the Sun has set. [Note: The sky brightness has been reduced in the chart.]

  • March 10th/11th before dawn: Saturn, Mars and a waning Moon. Mars below a waning Moon If clear before dawn on the 10th and 11th, looking just east of south, one should see a waning crescent Moon lying to the upper left of Mars on the 10th and Saturn on the 11th.

  • March 19th after sunset: Venus, Mercury and a very thin crescent Moon.Looking West after sunset on the 19th and given a very low western horizon, one might be able to spot Venus near Mercury which is close to maximum elongation from the Sun. A very thin crescent Moon, just two days after new, will be seen up to their left. Binoculars may well be needed, but please do not use them before the Sun has set. A tough observing challenge! [Note: the sky brightness has been reduced in the chart.]

  • March 23rd evening: The Moon in the Hyades Cluster.In the evening of the 23rd of the month, the Moon, coming towards first quarter, will lie within the Hyades cluster. After it has set from the UK it will occult Aldebaran which is a red giant star lying between our solar system and the cluster.

  • March 8th and 24th: The Alpine Valley.These are two good nights to observe an interesting feature on the Moon if you have a small telescope. Close to the limb is the Appenine mountain chain that marks the edge of Mare Imbrium. Towards the upper end you should see the cleft across them called the Alpine valley. It is about 7 miles wide and 79 miles long. As shown in the image is a thin rill runs along its length which is quite a challenge to observe. The dark crater Plato will also be visible nearby. You may also see the shadow cast by the mountain Mons Piton lying not far away in Mare Imbrium. This is a very interesting region of the Moon!

  • This month we welcome two new presenters, Gabriela Perez and Jasmine Chan-Hyams who tell us what we can see in the Southern Hemisphere night sky during March 2018.

  • Introduction.I'm Gaby, I work at Space Place at the Carter Observatory, in Wellington New Zealand as a telescope operator. I've been staring at the Southern Skies for most of my life. As a child I saw the fully mapped-out globe and I became fascinated with space, ever since I have wanted to explore the universe beyond. Now I bring the universe to me (mostly through collecting its light) with my eyes, a pair of binoculars or a telescope.

    And I'm Jasmine, I am a PhD Biotech student at Victoria University of Wellington. But who I am is a scientist, a star-gazer and a story-teller. We wish a fond farewell to Claire who has contributed so much to this podcast over the years. Thank you for teaching me about treasuring that moment of awe when you share a wonder of the universe with someone who has never seen anything like it before. You will be sorely missed at Space Place and we wish you all the best in your new job!

    Looking up into the night skies is one of the true delights of living in the southern hemisphere; especially here in Aotearoa, New Zealand where it is easy to get away from the bright city lights and where we a get a broader and brighter view of the Milky Way.

    Early in the month of March we can look forward to gazing upon many star studded greek heroes and mythical creatures. We can use constellations as guideposts to find deep sky objects including beautiful nebulae and special features of our southern skies.

  • The region around Orion. Our journey begins with the Greek constellation Orion, who appears in the skies after full dark in north-north west for the month of March. For many of us finding the three bright stars that form Orion's belt were probably the first thing you could proudly identify as a child. These three stars are 2nd magnitude stars. You can also see with the naked eye Betelgeuse, located in Orion's armpit; a red supergiant hundreds of times larger than our sun. Yet the brightest star of this constellation is Rigel - a blue star at Orion's ankle. Blue stars are the hottest kind of stars you'll find in the night skies while red stars are cooler and burning up the last of their heat energy. Just below his belt you'll find the Orion Emission Nebula (M42)- a huge star forming cloud - more than two widths of our moon across, it lies about 1500 light years away. With the naked eye it appears as a diffuse cloudy patch. Through a telescope you can see the clouds of dust and gas, lit up by the baby stars they are forming.

    From Orion's belt it's just a star jump to the right and up to find Sirius, the brightest star in our skies. Sirius is seriously bright at about 20 times brighter than our sun and is only 8.6 lya. Sirius is part of the Canis Major constellation - one of the two dog companions that accompany the hunter Orion. Below Canis Major you can look for the two stars that form Canis Minor. The star Procyon, in Canis Minor, forms a triangle with the 1st magnitude stars Sirius and Betelgeuse.

    Within this "southern triangle" you can look for the Monoceros unicorn constellation - home to the gorgeous Rosette nebula. This nebula has a beautiful carnation pick colouring and can be seen with binoculars in the part of the constellation closest to Betelgeuse.

    Neighboring Orion is the zodiac constellation Taurus the Bull. Taurus and his fiery eye, the red giant Aldebaran, can be found low in our Northern-Western sky after sunset where we can easily make out his V shaped horns. Near his shoulder lies the Pleiades star cluster. On a clear dark night you can see seven points of light with the naked eye but it is best viewed with a pair of binoculars. The Pleiades is a young cluster of mostly hot blue stars, the big ones that burn up all their fuel quickly -they live fast and die young. These bright blue stars are said to be seven beautiful sisters. You can find the seven sisters sheltering in the shoulder of the bull hiding from Orion's amorous intentions.

  • Crab Nebula.

    After you get an eyeful of these blue beauties you can jump down to the Crab Nebula (M1) but you'll want a telescope for this part. M1 was the fist Messier object recorded by famous French astronomer Charles Messier in 1771. To find M1 with your telescope look for Aldebaran first then follow the bull's horn to the end, it will be close to the horizon. Large apertures are needed to make out the filamentous detail. The Crab Nebula is was first viewed more than a 1000 years ago, by ancient Chinese astronomers, who recorded a bright light forming in this area. They witnessed was a supernova - a dying star. At the heart of the Crab Nebula is the pulsar, the skeleton of the dying star. Although we cannot see it with a telescope we can listen to the radio waves it emits as it spins. We can listen to the song of supernova.

    You can enjoy looking for Orion, his hunting dogs, Taurus and the unicorn Monoceros throughout the early evenings of March. Now I'll hand over to Gabriela who'll tell us what planets we can see this month and features of the skies to the south.

  • The Planets - But if you are looking for planets in March, you'll need stay up late. Venus sets shortly after the sun but becomes increasingly visible in our twilight skies towards the end of the month. Jupiter rises in the late evening about midnight in mid-March. This gas giant reflects the light of our sun and outshines Sirius, becoming the brightest object in our night sky after the Moon. For those early risers Mars and Saturn are in the eastern horizon just before dawn. Around the 7th of March the planets will line up quite nicely on either side of the waxing gibbous Moon. On the 21st of March we can observe the Autumn equinox when there night and day will be of equal length.

  • Constellations and Nebulae -

    This is probably my favourite time of year to look at the Southern Skies because you can stay out late without either freezing to death or being eaten alive by mosquitoes and the most important objects stay high in the skies for longer. The Full Moon will occur mid-month on the 12th of March. So the beginning and end of March are excellent times to explore the deeper sky objects that you can only see from the southern hemisphere.

    Turning to the south horizon we look for the kite shaped Southern Cross constellation Crux. The Crux will be low in our South Eastern sky in early March after sunset. We can use the pointer stars, red-orange Alpha Centauri and blue-white Beta Centauri to identify the true Southern Cross.

    As night progresses, the Southern Cross journeys around the southern celestial pole, bringing with it the dark patches stretched out through our view of the Milky Way. Here these patched represents the Giant Moa -a now extinct large flightless bird native to New Zealand. These dark patches are where large interstellar objects, called Dark Nebulas, have blocked out the light from more distant stars - preventing their light reaching us here on Earth. Dark Nebulae are easily seen against the backdrop of the Milky Way as the large concentration of star-light surrounding them lets us see them better. The head of the Moa sits by the Crux, nearby Beta Cruxis and the Jewel Box Cluster. This dark nebula is usually known as the Coalsack nebula. Much like coal itself it could one day ignite as it becomes an active stellar nursery, shining up as one of the brightest sections of our skies.

    Following the Moa's ascent, Scorpius rises in the east. In Maori starlore we know it as the legendary fish hook of Maui. Where the Milky Way bulges, next to Scorpius, is Sagittarius A - the Galactic Centre - where we have the brightest view of our own galaxy. From the Galactic Centre we receive intense radio feedback from the super-massive black hole at the centre of our Milky Way.

    Using the Southern Cross we can find, Canopus, the second brightest true star in our sky. It is part of the Carina constellation, the keel of Argo Navis. The ship that used to dominate the night sky as the largest constellation. In March it is located above the Crux. In the centre of this constellation is the Great Carina Nebula which houses the giant red dying star Eta Carinae. It once illuminated our night sky as one of the brightest stars for a short period of time after it undertook a massive event known as an imposter supernova. Now this hardy star, encased in the Homunculus Nebula, has faded and can only be seen through a telescope.

    The globular star cluster 47 Tucanae will be high in the sky and faintly spotted to the naked eye by the tenth brightest star, the pancake star Achernar (It's spinning so fast it's flattened itself out a bit). Globular clusters are fascinating things. Their structure allows us witness stellar interactions but also allows us to pinpoint the smallest and faintest stars. The large bright stars are at the core while the outer stars are fainter creating a unique and beautifully ordered structure found only in globular clusters.

  • Magellanic Clouds - We can also look for two of our neighbouring galaxies - the Magellanic Clouds. You can see them without the aid of a telescope. But you will need to get away from the bright city lights on a dark moonless night. These two small irregular dwarf galaxies orbit our Milky Way. The gravitational, pull of our galaxy, warps and distorts them - pulling away clouds of dust and gas and even stars to form the Magellanic Stream. The SMC and LMC are actually connecting by a bridge of neutral helium, suggesting they were once the same object. The Magellanic Clouds are the furthest objects away from home that we can see from our backyards in the southern hemisphere.

  • G - That's it for us in the month of March. Thanks for tuning in. J - and we wish you all very happy star gazing.

    The night sky for February 2018

    Tue, 06/02/2018 - 10:00
    Northern Hemisphere

    Ian Morison tells us what we can see in the Northern Hemisphere night sky during February 2018.

  • Jupiter - Jupiter rises around 2 am at the beginning of the month and just before midnight by month's end. Initially it has a 36 arcsecond disk, shining at a magnitude of -2 but as the month progresses, its apparent diameter increases to 39 arcseconds and it brightens to magnitude -2.2. Jupiter will transit before dawn and so will enable the giant planet to be seen with the equatorial bands, sometimes the Great (but reducing in size) Red Spot and up to four of its Gallilean moons visible in a small telescope. Sadly, Jupiter, lying in Libra during the month, is heading towards the southern part of the ecliptic and will only have an elevation of ~20 degrees when crossing the meridian. Atmospheric dispersion will thus hinder our view and it might be worth considering purchasing the ZWO Atmospheric Dispersion Corrector to counteract its effects.

  • Saturn - Saturn, at the start of its new apparition, rises at around 5 am at the start of the month and just after 3 am at its end. With an angular size of ~15.5 arc seconds it climbs higher before dawn and so becomes easier to spot as the month progresses. Its brightness remains at +0.6 magnitudes. The rings were at their widest a few months ago and are still, at 26 degrees to the line of sight, well open. Saturn, lying in Sagittarius, is just 3 degrees above the topmost star of the 'teapot'. Sadly, even when at opposition later in the year it will only reach an elevation of just over 15 degrees above the horizon when crossing the meridian. Atmospheric dispersion will thus greatly hinder our view and it might be worth considering purchasing the ZWO Atmospheric Dispersion Corrector to counteract its effects.

  • Mercury - Mercury passes through superior conjuction (between us and the Sun) on the 17th February so will be lost in the Sun's glare until the very end of the month when it might just be glimpsed after sunset with its ~5 arc second disk having an unusually bright magnitude of -1.5.

  • Mars - Mars starts the month moving quickly eastwards in Scorpius close to Beta Scorpii (Graffias) but moves into Ophiuchus on the 8th of the month. Now a morning object at the start of its new apparition, it rises four hours or so earlier than the Sun. During the month, Mars has a magnitude which increases from +1.2 to +0.8 and an angular size of just 5.6, increasing to 6.6, arc seconds so no details will be seen on its salmon-pink surface. It will only reach an elevation of ~14 degrees before dawn at the start of the month and just 12 degrees by month's end.

  • Venus - Venus passed through superior conjunction (on the far side of the Sun) on January 9th and so, at the beginning of February will be lost in the Sun's glare, setting less than half an hour after the Sun. However, by month's end, shining with a magnitude of -3.9, it will set around an hour after the Sun and its 10 arc second disk should be easy to spot 30 minutes or so after sunset. However a low western horizon will be needed as it will then only have an elevation of ~5 degrees some way to the south of west.

  • Highlights
  • February 8th before dawn: A waning Moon close to Jupiter - with Mars nearby. If clear before dawn on the 8th, a waning moon between Full Moon and Last Quarter lies close to Jupiter. Down to the left is Mars lying above Antares in Scorpius.

  • February 9th before dawn: Mars and a waning Moon. If clear before dawn on the 9th and looking to the South-southeast, Mars, at magnitude +1, will be seen to the lower right of a waning crescent Moon.

  • February 17th after sunset: Venus and a thin crescent Moon. Looking West-Southwest after sunset on the 17th and given a very low western horizon, one might be able to spot Venus at the start of its new evening apparition. A very thin crescent Moon, just two days after new, will be seen up to its left. Binoculars may well be needed, but please do not use them before the Sun has set. A very tough observing challenge!

  • February 23rd/24th evening: The Moon in a beautiful skyscape. In the evenings of the 23rb and 24th of the month, the Moon, coming towards first quarter, will pass through Taurus and Orion. On the 23rd, it will lie close to Aldebaran and on the 24th lie above Orion.

  • February 6th and 22nd evening: The Hyginus Rille. For some time a debate raged as to whether the craters on the Moon were caused by impacts or volcanic activity. We now know that virtually all were caused by impact, but it is thought that the Hyginus crater that lies at the centre of the Hyginus Rille may well be volcanic in origin. It is an 11 km wide rimless pit - in contrast to impact craters which have raised rims - and its close association with the rille of the same name associates it with internal lunar events. It can quite easily be seen to be surrounded by dark material. It is thought that an explosive release of dust and gas created a vacant space below so that the overlying surface collapsed into it so forming the crater.

  • In her final broadcast for the Jodcast, Claire Bretherton from the Carter Observatory in New Zealand tells us what we can see in the Southern Hemisphere night sky during February 2018.

    Kia ora and welcome to the February Jodcast from Space Place at Carter Observatory in Wellington, New Zealand.

  • Lunar Eclipse - Whilst the Earth blocks all direct light from the Sun, some light passes though the Earth's atmosphere and is bent or refracted towards the surface of the Moon. Light with shorter wavelengths, towards the blue end of the spectrum, is scattered more strongly, so only the redder light gets through, giving the eclipsed moon a telltale reddish glow.

  • Partial Solar Eclipse - Whilst New Zealand won't see it, some parts of the southern hemisphere will also experience a partial solar eclipse this month, on the morning of the 16th NZ time. From parts of Chile and Argentina the moon will cover some 25% of the Sun's disk, whilst from Antarctica around 49% will be covered.

  • Orion - Orion is now high in the north after dark, with Sirius, or Takurua, the brightest star in our night-time sky, even higher.

  • Procyon - Below and to the right, and forming a triangle with Sirius and Betelgeuse, is Procyon, the brighter of the two main stars that form the constellation of Canis Minor, Orion's small hunting dog. Procyon is the eighth brightest star in the night-time sky and, like Sirius (at ~9 ly distant), is one of our Sun's nearest neighbours at just 11 light years away. Also like Sirius, it is in fact a binary system, with a 1.5 solar mass primary and a faint white dwarf companion.

  • Clusters and Nebulae - Just over a third of the way between Sirius and Procyon, in the constellation of Monoceros, is M50, a pretty, heart-shaped open cluster of stars, visible in binoculars.

  • Around a third of the way from Betelgeuse to Procyon is NGC2244, a rectangular cluster of stars that is embedded in a faint nebula called the Rosette. Whilst the cluster is visible in binoculars and small telescopes, the nebula is more of a challenge and is best seen in long exposure photographs.

    Below Canis Minor sits another pair of stars, Castor and Pollux, marking the heads of Gemini, the twins. Pollux, the higher and brighter of the two stars, is the 17th brightest star in our night sky. It is about 35 light years away from us, whilst Castor is in fact a sextuple star system located 52 light years from Earth.

    Nearby to Eta Geminorum, at the foot of the twin of Castor, is the open star cluster M35, covering an area almost the size of the full moon. Under good conditions it can be seen with the unaided eye as a hazy star, but binoculars or a wide-field telescope will reveal more detail and are the best ways to view this lovely cluster.

    Next to Gemini is the faint zodiac constellation of Cancer, the crab. At the centre of Cancer is a lovely open cluster of stars known as M44, Praesepe (the Manger) or the Beehive. At magnitude 3.7, the cluster is visible to the naked eye as a hazy nebula, and has been know since ancient times. It was one of the first objects Galileo studied when he turned his telescope to the skies in 1609.

    Galileo was able to pick out around 40 stars, but today we know that Praesepe contains over 1000 individual members, with a combined mass of between 500 and 600 times that of the Sun. As one of the closest open star clusters to our Solar System, M44 is a great target for binoculars or small telescopes, which will easily reveal a number of individual stars within it.

    Higher, and to the east of Canis Major is Puppis, representing the Poop deck of the great ship Argo, which we explored last month. Inside Puppis are two lesser known Messier Objects, M46 and M47.

    Messier 46 (also known as NGC 2437) is a rich open cluster at a distance of about 5,500 light-years away. M46 is estimated to contain around 500 stars, of which around 150 of magnitude 10-13. Estimated to be only 300 million years old, this is a young cluster, and a lovely sight in binoculars or a small telescope. Astronomer John Herschel described it in his General Catalogue of Nebulae and Clusters of Stars as “Remarkable, cluster, very bright, very rich, very large, involving a planetary nebula". This planetary nebula, located near the cluster's northern edge, is NGC 2438.

    A planetary nebula is formed when a low or intermediate mass star comes to the end of its life, ejecting its outer layers into space as a glowing shell of ionized gas.

    Located around 1 degree west is another open cluster, M47. The two fit easily within one binocular field of view, and are often referred to as sisters.

    Messier 47 or NGC 2422 has actually been discovered several times. The first was some time before 1654 by Giovanni Batista Hodierna and then independently by Charles Messier on February 19, 1771. William Herschel also independently rediscovered it on February 4, 1785, and it was included as GC 1594 in John Herschel's General Catalogue of Nebulae and Clusters of Stars (the precursor to Dreyer's New General Catalogue) in 1864.

    Due to a sign error by Messier, the cluster was considered a 'lost Messier Object' for many years, as no cluster could be found at the position of Messiers original coordinates. It wasn't until 1959 that Canadian astronomer T. F. Morris identified that the cluster was in fact NGC2422, and realized Messier's mistake.

    M47 lies at a distance of around 1,600 light-years from Earth with an estimated age of about 78 million years. It is described as a course, bright cluster containing around 50 stars, scattered over an area around the same size as the full moon in the sky. It is bright enough to be glimpsed with the naked eye under good observing conditions, but best viewed with binoculars or a small telescope.

    There are a couple of other excellent binocular targets in Puppis, including open cluster NGC2477 - a wonderful, rich cluster of over 300 stars, described by American Astronomer Robert Burnham as "probably the finest of the galactic clusters in Puppis" along with its neighbor NGC 2451, both located close to the second magnitude star Zeta Puppis.

    Also known as Naos, this blue supergiant is one of the hottest, most luminous stars visible to the naked eye. It has a bolometric (total) luminosity of at least 500,000 times that of the Sun, but with most of its radiation emitted in the ultraviolet it is visually around 10,000 times brighter. It is also one of the closest stars of its kind to our Sun, at a distance of around 1,080 ly.

  • Planets - Our evening skies are still bereft of bright planets. Jupiter is the first to rise at around 1 am at the start of the month. Mars follows shortly afterwards, and the two are joined by Saturn around 3:30 am. You may spot Mercury briefly at the start of February, rising in the dawn twilight around an hour before the Sun, but it will soon disappear from view as it heads back towards the Sun. By months end Jupiter has moved into our evening skies, rising at 11 pm, Mars around 12:30 am and Saturn by 2 am, making a diagonal line down the eastern morning sky.

  • Farewell - After 8 years at Space Place at Carter Observatory, and being involved with the Jodcast for almost as long, I am moving on to a new role in February and so sadly this will be my last southern skies section. It's been a great pleasure bringing you a little taster of our wonderful New Zealand stars and some of the amazing stories within them over the past few years. I wish you clear skies and all the very best for the future. So farewell from me, Claire Bretherton, and the team here at space Place at Carter Observatory.