December 2021 – What’s Up!

Week of 6th December

  • Astronomical twilight ends at 18:02 UT at the start of the week and at 18:02 UT by the end of the week
  • The waxing Crescent Moon parades past the naked eye planets this week, near to Venus (mag -4.7) on Monday, Saturn (+0.7) on Wednesday and Jupiter (-2.3) on Thursday
  • Comet C/2021 A1 Leonard, currently visible in our pre-dawn sky in binoculars at around mag +7, will become visible in our evening sky this week. Look 40 to 50 degrees further west of Venus at a similar altitude at around 16:30 UT to try and spot the comet. Predictions suggest that it could even become naked eye visible by the end of the week
  • The Moon is First Quarter on Saturday
  • The Sun currently has 3 active regions: AR2901, AR2902 and AR2904. The sunspot number is 35
  • There are visible evening ISS passes this week as follows:
    Monday: 16:59, W to SE, max 46° and 18:37, WSW to SSW, max 12°
    Tuesday: 17:49, W to S, max 18°
    Wednesday: 17:01, W to SSE, max 25°
    Friday: 17:04, WSW to SSW max 12°

November 2021 – What’s Up!

Week of 29th November

  • Astronomical twilight ends at 18:04 GMT at the start of the week and at 18:02 GMT by the end of the week
  • Venus (mag -4.7), in waning crescent phase, is low in our southwestern evening sky around sunset, setting itself at around 18:40
  • On Saturday, there is a total solar eclipse, but unfortunately for us, it is only visible from Antarctica. A partial solar eclipse will be visible across parts of the southern hemisphere
  • The Moon is New on Saturday
  • The Sun currently has 3 active regions: AR2898, AR2899 and AR2900. The sunspot number is 53
  • There are multiple visible evening ISS passes this week as follows:
    Monday: 17:40, W to E, max 84° and 19:16, W, max 17°
    Tuesday: 16:52, W to E, max 88° and 18:29, W, max 57°
    Wednesday: 17:42, W to ESE, max 87° and 19:19, W, max 16°
    Thursday: 16:55, W to E, max 86° and 18:32, W to SW, max 44°
    Friday: 17:44, W to SE max 61° and 19:22, W to WSW, max 13°
    Saturday: 16:57, W to ESE, max 75° and 18:34, W to SSW, max 25°
    Sunday: 17:47, W to SE, max 34°

Week of 22nd November

  • Astronomical twilight ends at 18:08 GMT at the start of the week and at 18:04 GMT by the end of the week
  • Five planets stretch across the ecliptic, starting in the West with Venus (mag -4.6), then Saturn (+0.7), Jupiter (-2.3), Neptune (+7.9) and in the East, Uranus (+5.7)
  • Two dwarf planets are also in our sky: Pluto (+14.4) in the West and Ceres (+7.2) in the East in Taurus. Ceres reaches opposition on Saturday and is also at perigee, its closest point to Earth, making it appear at its brightest
  • Comet C/2021 A1 (Leonard) is in our early morning sky, moving East between Ursa Major and Leo. It is currently at mag +8.5, but estimated to reach +7.4 by Sunday and brighter through early December. Could Leonard impress the early risers? It is highest in the sky before dawn at around 05:00 to 06:00 GMT. It is not in our sky for long as it moves south, below our horizon by mid December
  • The Moon is Last Quarter on Saturday
  • The Sun currently has 2 active regions: AR2896 and AR2897. The sunspot number is 22
  • There are multiple visible evening ISS passes this week as follows:
    Monday: 16:46, SE, max 10° and 18:19, SW to S, max 39°
    Tuesday: 17:33, SSW to ESE, max 30° and 19:06, WSW, max 21°
    Wednesday: 16:46, SSW to E, max 22° and 18:22, WSW to SSW, max 66°
    Thursday: 17:35, WSW to E, max 55° and 19:11, W, max 20°
    Friday: 16:48, SW to E max 41° and 18:24, W, max 71°
    Saturday: 17:37, WSW to E, max 83° and 19:14, W, max 18°
    Sunday: 16:50, WSW to E, max 71° and 18:27, W to WNW, max 62°

Week of 15th November

  • Astronomical twilight ends at 18:14 GMT at the start of the week and at 18:09 GMT by the end of the week
  • On Tuesday there is a shadow transit of Ganymede across the disk of Jupiter (mag -2.4). The transit starts at 19:08 GMT and finishes at 22:36 GMT. Find Jupiter in the southwest at about 15° altitude
  • Wednesday sees the peak of the Leonid meteor shower. The ZHR is around 15 meteors, but this will be impeded by the bright 98% full Moon. The shower is caused by debris deposited by comet 55P/Tempel-Tuttle
  • On Friday morning there is a partial lunar eclipse; the Moon will enter the Earth’s penumbra at 06:03 GMT. Unfortunately, the majority of the eclipse will not be visible from Marlborough as the Moon sets at 07:31 GMT
  • The Moon is Full on Friday
  • The Sun currently has 3 active regions: AR2893, AR2894 and AR2895. The sunspot number is 24
  • There are multiple visible evening ISS passes this week as follows:
    Friday: 19:08, SW to SSW, max 11°
    Saturday: 18:23, SSW to S, max 21°
    Sunday: 17:39, S to ESE, max 17° and 19:14, WSW to WSW, max 17°

Week of 8th November

  • Astronomical twilight ends at 18:23 GMT at the start of the week and at 18:16 GMT by the end of the week
  • The waxing Moon passes the planets through this week, making its close approach to Venus (mag -4.5) on Monday at sunset as a thin crescent, Saturn (+0.6) on Wednesday when 41% illuminated and Jupiter (-2.4) on Thursday when it will be First Quarter. On Saturday it will be near to Neptune (+7.9), but this pairing will be hard to spot, even in binoculars as the Moon will be 73% illuminated at mag -10.7
  • Comet 67P/Churyumov-Gerasimenko, famous for the Rosetta mission and successful Philae lander in 2014, is at its brightest this week, though still only at mag +10. On Tuesday it is located about 2° below Pollux, heading southeast
  • The Moon is First Quarter on Thursday
  • The Sun currently has 3 active regions: AR2891, AR2893 and AR2894. The sunspot number is 41
  • There are no visible evening ISS passes this week

Week of 1st November

  • Astronomical twilight ends at 18:33 GMT at the start of the week and at 18:24 GMT by the end of the week
  • Venus (mag -4.4) is visible close to the southwestern horizon around sunset, setting itself at about 18:30 GMT
  • Saturn (+0.6) and Jupiter (-2.5) are in our southwestern evening sky. On Monday, Saturn sets at 22:21 GMT and Jupiter sets at 23:48 GMT
  • Uranus (+5.7) is at opposition on Thursday. Find the planet in the southeast at an altitude of about 40°. You will need binoculars or a small telescope to see Uranus
  • The Taurid meteor shower peaks on Thursday. It is a minor shower with a ZHR of only 5 to 10 meteors, but it can produce spectacular fireballs. Unusually, the shower is caused by two debris streams, the first from Asteroid 2004-TG10 and the second from Comet 2P/Enke
  • The Moon is New on Thursday
  • The Sun currently has 4 active regions: AR2887, AR2889, AR2891 and AR2892. There is a further active region emerging around the oncoming limb, as yet un-numbered. The sunspot number is 76
  • There are no visible evening ISS passes this week

October 2021 – What’s Up!

Week of 25th October

  • Astronomical twilight ends at 19:45 BST at the start of the week and at 18:34 GMT by the end of the week
  • Daylight Saving Time ends on Sunday and the clocks move from BST back one hour to rejoin GMT
  • Marlborough Dark Skies Festival is on all week, with the Museum of the Moon in the College Chapel and multiple events lined up for the weekend – check the festival website for full details
  • Mercury reaches Greatest Elongation West on Monday, making it visible in the eastern morning sky at an altitude of about 14°
  • Venus reaches Greatest Elongation East on Friday and is visible at an altitude of about 9° in the southwestern sky just after sunset
  • Saturn (+0.6) and Jupiter (-2.5) are visible in our western evening sky. Saturn now sets before midnight, so this apparition is approaching completion
  • The Moon is Last Quarter on Thursday
  • The Sun currently has 2 active regions: AR2886 and AR2887. The sunspot number is 32
  • There are no visible evening ISS passes this week

Week of 18th October

  • Astronomical twilight ends at 19:58 BST at the start of the week and at 19:47 BST by the end of the week
  • The Orionid meteor shower peaks on Thursday. It is a relatively small shower, with a ZHR of only around 15, caused by debris deposited by comet 1P/Halley. Its radiant appears in the constellation of Orion. Unfortunately, the Full Moon this year will drown out all but the brightest meteors
  • Saturn (+0.6) and Jupiter (-2.6) are moving ever further West in our evening sky, so enjoy the beautiful gas giants now, while they are still visible
  • The Moon is Full on Wednesday – the Hunter’s Moon
  • The Sun currently has 1 active region: AR2882. The sunspot number is 11
  • There are no visible evening ISS passes this week

Week of 11th October

  • Astronomical twilight ends at 20:13 BST at the start of the week and at 20:00 BST by the end of the week
  • Venus (mag -4.3) is currently visible low to the horizon in the southwestern sky around sunset
  • Saturn (+0.5) and Jupiter (-2.6) continue to dominate our southern evening sky. They will be joined by the waxing crescent Moon on Thursday and Friday
  • The Moon is First Quarter on Wednesday
  • The Sun currently has 1 active region: AR2882. The sunspot number is 14
  • There are no visible evening ISS passes this week

Week of 4th October

  • Astronomical twilight ends at 20:29 BST at the start of the week and at 20:15 BST by the end of the week
  • Saturn (+0.5) and Jupiter (-2.7) provide the highlight of our evening sky. On Monday, watch a double moon shadow transit across Jupiter as the shadows of Callisto and Ganymede move across the planet’s disk from 19:51 to 23:26 BST
  • The peak of the Draconids meteor shower is on Thursday. It is a minor shower caused by debris from comet 21P/Giacobini-Zinner, with a ZHR of only 10 meteors, though it has produced much higher outbursts in recent years
  • The Moon is New on Wednesday
  • The Sun currently has 2 active regions: AR2877 and AR2880. The sunspot number is 25
  • The ISS makes multiple visible evening passes this week as follows:
    Monday: 20:10, W to S, max 16°
    Tuesday: 19:23, W to SSE, max 23°
    Thursday: 19:26, WSW to SSW, max 11°

September 2021 – What’s Up!

Week of 27th September

  • Astronomical twilight ends at 20:45 BST at the start of the week and at 20:31 BST by the end of the week
  • Saturn (+0.5) and Jupiter (-2.7) continue to dominate our southern night sky and are perfectly placed for observation this week. Watch the transit of Jupiter’s moon, Io and its shadow on Wednesday evening; the transit commences at 18:55 BST and finishes at 21:15 BST
  • The Moon is Last Quarter on Wednesday
  • The Sun currently has 2 active regions: AR2871 and AR2872. The sunspot number is 38
  • The ISS makes multiple visible evening passes this week as follows:
    Monday: 20:51, W to S, max 73°
    Tuesday: 20:03, W to ESE, max 86° & 21:40, W, max 20°
    Wednesday: 19:16, W to E, max 87° & 20:53, W to SSW, max 44°
    Thursday: 20:06, W to SE, max 58° & 21:43, W to WSW, max 12°
    Friday: 19:18, W to ESE, max 73° & 20:55, W to SSW, max 23°
    Saturday: 20:08, W to SSE, max 32°
    Sunday: 19:21, W to SE, max 43° & 20:59, WSW to SSW, max 11°

Week of 20th September

  • Astronomical twilight ends at 21:03 BST at the start of the week and at 20:48 BST by the end of the week
  • The Autumn Equinox occurs on Wednesday. At 20:21 BST the Sun will cross the Celestial Equator, heading south. This marks the start of autumn here in the Northern Hemisphere. There will be almost exactly 12 hours of night and day across our planet
  • It is currently possible to spot five planets: Venus (mag -4.1) is setting low in our western evening sky, Saturn (+0.4) and Jupiter (-2.8) are high through the night, transiting at around 22:00 BST, Neptune (+7.8) follows further east and Uranus (+5.7) rises at 20:24 BST. For a sixth solar system planet, look to your feet to add Earth to the list!
  • The Moon is Full on Tuesday – the Harvest Moon
  • The Sun currently has 1 active region: AR2871. The sunspot number is 11
  • The ISS makes multiple visible evening passes this week as follows:
    Monday: 19:54, SW to E, max 31° & 21:30, WSW, max 49°
    Tuesday: 20:43, WSW to E, max 72° & 22:20, W, max 14°
    Wednesday: 19:56, WSW to E, max 58° & 21:33, W, max 44°
    Thursday: 20:46, W to E, max 87° & 22:23, W, max 12°
    Friday: 19:59, WSW to E, max 86° & 21:36, W, max 35°
    Saturday: 20:49, W to E, max 87°
    Sunday: 20:02, W to E, max 84° & 21:39, W, max 27°

Week of 13th September

  • Astronomical twilight ends at 21:22 BST at the start of the week and at 21:06 BST by the end of the week
  • Neptune reaches opposition on Tuesday, when it will be opposite the Sun as seen from Earth. It will be best placed for observation, appearing at its brightest, though still faint at mag +7.8, so binoculars or a telescope will be needed to see the planet. Look southeast in the constellation of Aquarius through the evening
  • Saturn (mag +0.4) and Jupiter (-2.8) continue to dominate our evening skies. They will be joined by the waxing Gibbous Moon towards the end of the week
  • The Moon is First Quarter on Monday
  • The Sun currently has 5 active regions: AR2863, AR2864, AR2866, AR2868 and AR2869. The sunspot number is 93
  • The ISS makes multiple visible evening passes this week as follows:
    Thursday: 21:27, SW to SSW, max 14°
    Friday: 20:41, SSW to SSE, max 23°
    Saturday: 19:57, S to ESE, max 17° & 21:32, WSW to SW, max 31°
    Sunday: 20:47, SW to ESE, max 46°

Week of 6th September

  • Astronomical twilight ends at 21:42 BST at the start of the week and at 21:25 BST by the end of the week
  • On Thursday evening, spot the 3 day old waxing Crescent Moon just under 7° from Venus (mag -4.1) as they set in the West. Look just after sunset, which is at 19:34 BST
  • Jupiter (-2.8) and Saturn (+0.3) are well placed in our evening skies
  • With little to no moonlight, this week is the perfect opportunity to observe M27, the Dumbbell Nebula, a planetary nebula in the constellation of Vulpecula, just below Cygnus. At mag +7 and only 8 arcminutes in size, you will need a good pair of binoculars or a telescope to find it
  • The Moon is New on Tuesday
  • The Sun currently has 5 active regions, AR2863, AR2864, AR2865, AR2866 and AR2867. The sunspot number is 68
  • There are no visible evening ISS passes this week

 

August 2021 – What’s Up!

Week of 30th August

  • Astronomical twilight ends at 22:03 BST at the start of the week and at 21:45 BST by the end of the week
  • On Wednesday, Mercury (mag 0.0) reaches its highest point in the evening sky. It will be at 5° above the western horizon at sunset (19:52 BST). Take care of the setting Sun if searching for the planet, especially if using binoculars. Venus (-4.0) can be found 15° further East at about 9° altitude
  • Saturn (mag +0.3) and Jupiter (-2.9) are well placed for observation in our evening sky this week, with Saturn culminating at 23:04 BST and Jupiter an hour later. To complete the suite of planets, find Neptune (+7.8) and  Uranus (+5.7) further East along the ecliptic
  • The Moon is Last Quarter on Monday
  • The Sun currently has 4 active regions, AR2859, AR2860, AR2861 and AR2862. The sunspot number is 77
  • There are no visible evening ISS passes this week

Week of 23rd August

  • Astronomical twilight ends at 22:24 BST at the start of the week and at 22:06 BST by the end of the week
  • Venus makes a brief appearance in our western evening sky around sunset, shining at magnitude -4.0, but has set itself by 21:20 BST
  • Four more planets are on view through the night, with, from West to East, Saturn (mag +0.3), followed by Jupiter (-2.9), then Neptune (+7.8) and finally Uranus (+5.7), which rises at 22:19 BST
  • The Moon is waning Gibbous all week, not reaching Last Quarter until next Monday
  • The Sun currently has 2 active regions, AR2858 and AR2859. The sunspot number is 25
  • There are no visible evening ISS passes this week

Week of 16th August

  • Astronomical twilight ends at 22:47 BST at the start of the week and at 22:28 BST by the end of the week
  • Jupiter reaches opposition on Thursday. In this celestial position, opposite the Sun for us on Earth, it is best placed for observation, being at its brightest (mag -2.9) and largest with an apparent size of 49 arcseconds. This is the perfect time to train binoculars or a telescope on the Gas Giant, which you will find in the southeastern evening sky
  • On Sunday, Jupiter rises at 20:06 BST in the east-southeast with a double moon transit in progress. Two of its Galilean moons, Europa and Ganymede, will be crossing in front of the planet and their shadows will also be visible on the planet’s surface. The event ends when Ganymede’s shadow leaves the disc at 23:20 BST
  • The Moon is Full on Sunday – the Sturgeon Moon. It is the third of four Full Moons in the period from the summer solstice to the autumn equinox and as such, is called a Blue Moon
  • The Sun currently has 4 active regions, AR2853, AR2855, AR2856 and AR2857. The sunspot number is 47
  • There are no visible evening ISS passes this week

Week of 9th August

  • Astronomical twilight ends at 23:11 BST at the start of the week and at 22:50 BST by the end of the week
  • On Wednesday evening, the 3 day old waxing crescent Moon will make a close approach to Venus (mag -4.0), appearing with just 5° of separation low in the western sky just after sunset
  • The Perseid meteor shower peaks on Thursday night, with a maximum zenithal hourly rate of around 150 meteors per hour, making it one of the most active showers of the year. The favourable Moon phase makes for optimum observing conditions through the night. The shower runs from 14th July to 24th August, so meteors can be spotted throughout that period. The shower is created by debris from comet 109P/Swift-Tuttle
  • Saturn (+0.2) and Jupiter (-2.9) continue to adorn our evening skies in the southeast
  • The Moon is First Quarter on Sunday
  • The Sun currently has no active regions. The spotless stretch is 2 days
  • There are no visible evening ISS passes this week

Week of 2nd August

  • Astronomical twilight ends at 23:38 BST at the start of the week and at 23:15 BST by the end of the week
  • Saturn reaches opposition on Monday, when it lies opposite the Sun in the sky. It is best placed for observation at this time as it appears at its largest and brightest at 18.6 arcseconds in apparent size and magnitude +0.2. At opposition, Saturn’s rings show a discernible brightening, known as the Seeliger Effect
  • Jupiter is about 20° further East in the southeastern evening sky, shining at magnitude -2.8
  • The Moon is New on Sunday
  • The Sun currently has no active regions. The spotless stretch is 4 days
  • There are no visible evening ISS passes this week

 

July 2021 – What’s Up!

Week of 26th July

  • Astronomical twilight ends at 00:15 BST at the start of the week and at 23:42 BST by the end of the week
  • Look out for the waning Gibbous Moon in close proximity to Jupiter (mag -2.8) on Monday evening in the southeast
  • The delta Aquarid meteor shower is active this week, with its peak on Wednesday. The bright Moon will reduce visibility to all but the brightest meteors. The shower has a max ZHR of 25 and its progenitor is comet P/2008 Y12 (SOHO)
  • The Moon is Last Quarter on Saturday
  • The Sun currently has two active regions, AR 2846 and 2847. The sunspot number is 35
  • The ISS makes multiple evening passes this week as follows:
    Monday: 22:55, W to SW, max 33°
    Tuesday: 22:08, W to SE, max 45° and 23:46, WSW to SW, max 11°
    Wednesday: 22:58, W to SSW, max 17°
    Thursday: 22:10, W to SSE, max 24°

Week of 19th July

  • Astronomical darkness returns this week as astronomical twilight ends at 00:55 BST on Wednesday and at 00:21 BST by the end of the week
  • Venus (mag -3.9) and Mars (+1.8) are both visible in our evening sky throughout this week; look low to the western horizon just after sunset
  • The Full Moon makes a close approach to Saturn (+0.2) on Saturday and Jupiter (-2.8) on Sunday. Look to the southeastern horizon to find the gas giants at around 23:00 BST
  • The Moon is Full on Saturday – the Buck Moon, also known as the Hay Moon and the Thunder Moon
  • The Sun currently has four active regions, AR 2842 in the northern hemisphere and 2843, 2844 & 2845 in the southern hemisphere. AR 2844 is a particularly rare high-latitude active region. The sunspot number is 53
  • The ISS makes multiple evening passes this week as follows:
    Monday: 21:59, WSW to E, max 72° and 23:36, W to E, max 86°
    Tuesday: 22:49, W to E, max 84°
    Wednesday: 22:01, W to E, max 87° and 23:38, W to ESE, max 75°
    Thursday: 22:51, W to ESE, max 87°
    Friday: 22:04, W to E, max 86° and 23:40, W to S, max 45°
    Saturday: 22:53, W to SE, max 60°
    Sunday: 22:06, W to ESE, max 74° and 23:43, W to SW, max 24°

Week of 12th July

  • Astronomical twilight does not end until 00:55 BST on 21st July
  • On Monday, the shadow of Jupiter’s moon, Callisto, will transit the planet’s disk. The transit starts at 22:48 BST, before Jupiter rises at 22:55 BST, and ends at 03:32 BST.  The shadow will be visible just above the Great Red Spot
  • Mercury is at its highest altitude in the morning sky on Tuesday. It rises at 03:43 BST, with sunrise at 05:05 BST. The planet (mag -0.4) will be 19° from the Sun and will reach a maximum visible altitude of 11°
  • Tuesday’s evening sky features Venus (mag -3.9) and Mars (+1.8) making a close approach to each other. They will appear with just 29 arcminutes of separation. Look to the western horizon soon after sunset (21:19 BST)
  • On Friday night it will be possible to spot the clair-obscur effects that produce the Lunar ‘V’ and ‘X’ at the Moon’s terminator. Look at around 22:45 BST with binoculars as the Moon approaches the western horizon
  • The Moon is First Quarter on Saturday
  • The Sun currently has two active regions, AR 2841 and AR 2842. The sunspot number is 24
  • The ISS makes multiple evening passes this week as follows:
    Monday: 22:41, S to ESE, max 16°
    Tuesday: 23:29, SW to E, max 42°
    Wednesday: 22:42, SSW to E, max 31°
    Thursday: 23:31, WSW to E, max 71°
    Friday: 22:44, WSW to E, max 56°
    Saturday: 21:57, SW to E, max 42° and 23:34, W to E, max 87°
    Sunday: 22:46, WSW to E, max 84°

Week of 5th July

  • Astronomical twilight does not end until 00:55 BST on 21st July
  • The Earth reaches aphelion on Monday, when it will be at its most distant point from the Sun in its annual orbit. There will be 1.02 AU or 152,100,527 km, between the Earth and the Sun
  • Venus (mag -3.9) and Mars (1.8) continue to feature in our evening sky. Look just a few degrees above the western horizon after sunset at around 21:30 BST to find the pair
  • The waning Moon means dark skies this week, the perfect time to search in and around the Summer Triangle for fainter objects such as M57, the Ring Nebula in Lyra. Binoculars or a telescope will be required
  • The Moon is New on Saturday
  • The Sun currently has four active regions, AR 2835, AR 2386, AR 2387 and AR 2388. The sunspot number is 81
  • The ISS returns to our evening sky this week with one visible pass:
    Sunday: 23:31, ESE to E, max 18°

June 2021 – What’s Up!

Week of 28th June

  • Astronomical twilight does not end until 00:55 BST on 21st July
  • Watch the planets Venus (mag -3.9) and Mars (+1.8) appear ever closer to eachother through this week in our evening sky. Look to the western horizon to see the pair just after sunset
  • The waning gibbous Moon passes by both Saturn (mag +0.4) and Jupiter (-2.6) on Monday and Tuesday. Look southeast, just above the horizon around 00:00 BST to see the solar system objects
  • Mercury reaches greatest elongation west on Sunday, appearing with 21.6° separation from the Sun in the morning sky just before sunrise
  • The Moon is Last Quarter on Thursday
  • The Sun currently has one active region, AR 2835. The sunspot number is 16
  • There are no visible evening ISS passes this week

Week of 21st June

  • Astronomical twilight does not end until 00:55 BST on 21st July
  • The Summer Solstice occurs at 04:25 BST on Monday, when the Sun will be at its most Northerly point in the sky with a declination of +23.5°. It will have an altitude of 62° at 13:00 BST, its highest point in the sky of the year. Monday will be the longest day of the year for us in the Northern Hemisphere and Monday night the shortest night, with only 7 hours 21 minutes between sunset and sunrise. The rising and setting of the Sun are also at their most northerly point of the year, with sunrise on Monday happening at an azimuth of just 49°, compare this with sunrise on the Winter Solstice at an azimuth of 128°!
  • On Wednesday, Mars (mag +1.8) will be in conjunction with M44 the Beehive Cluster in Cancer. Look to the north-northwest horizon after sunset to find the planet and cluster. Venus (-3.9) will be just a few degrees further west
  • The Moon is Full on Thursday – the Strawberry Moon (nothing to do with its colour, but so named as it indicates the time of year to gather ripening fruit)
  • The Sun currently has one active region, AR 2833. The sunspot number is 15
  • There are no visible evening ISS passes this week

Week of 14th June

  • Astronomical twilight does not end until 00:55 BST on 21st July
  • The Milky Way is well placed for observation this week as it rises higher in our evening sky. Use a pair of binoculars to take in the wealth of stars and dusty regions along the visible disc of our galaxy. Try to find the ‘Coathanger’ asterism in Vulpecula by first locating the wonderful double star Albireo, the beak of Cygnus, and then move a few degrees southwest to spot the upside down coathanger pattern of stars
  • The gas giants Saturn and Jupiter are returning to our evening skies now, with Saturn rising at 23:57 BST at magnitude +0.5 and Jupiter following a little later at 00:42 BST, shining at mag -2.5
  • The Moon is First Quarter on Friday
  • The Sun currently has one active region, AR 2833, emerging around the oncoming mid-latitude northern hemisphere limb
  • There are no visible evening ISS passes this week

Week of 7th June

  • Astronomical twilight does not end until 00:55 BST on 21st July
  • There is a solar eclipse on Thursday, appearing as an annular eclipse to those in Canada and Greenland, while it will be a partial eclipse for us here in Marlborough. First contact is at 10:06 BST, with maximum eclipse at 11:11 BST, when about 21% of the Sun will be obscured by the Moon. Last contact is at 12:20 BST. Hopefully the weather will allow a live stream to be broadcast. Take great care if trying to observe the partial eclipse yourself
  • The Arietid meteor shower peaks on Thursday at around 15:00 BST. This is during daylight hours, so whilst meteors won’t be seen by eye, the radio meteor detector should see an increase in activity – watch the live stream to observe meteors in broad daylight!
  • The Moon is New on Thursday
  • The Sun currently has two active regions, AR 2827 and AR 2829. The sunspot number is 30. There has been a significant increase in solar activity so far this year, with only 29% of days being spotless. Compare this with 57% spotless days in 2020 and 77% spotless days in 2019
  • There are no visible evening ISS passes this week

May 2021 – What’s Up!

Week of 31st May

  • Astronomical twilight does not end until 00:55 BST on 21st July
  • This week’s challenge is to hunt down the array of Globular Clusters above the arc of the Milky Way. These include M3 (in Bootes), M13 (the Great Hercules Cluster) and M92 (in Hercules), M5 (in Serpens) and M10 and M14 (in Ophiuchus). Binoculars or a small telescope will suffice to spot these magnificent balls of stars
  • The Moon is Last Quarter on Wednesday
  • The Sun currently has two active regions, AR 2824 (off going) and AR 2827 (a new on coming region). The sunspot number is 26
  • There are no visible evening ISS passes this week

Week of 24th May

  • Astronomical twilight does not end until 00:55 BST on 21st July
  • Noctilucent cloud season starts around now, so keep an eye out near the northern horizon around 90 minutes after sunset to try and spot these beautiful, high level night shining, opalescent clouds
  • There is a total lunar eclipse on Wednesday. Unfortunately, it is not visible from the UK, but only visible from Oceania, the Americas and Eastern and Southeast Asia
  • The Moon is Full on Wednesday – the Flower Moon. As the Moon will be very close to perigee, this will make it a ‘supermoon’. It will be the largest and brightest full Moon of 2021
  • The Sun currently has one active region, AR 2824. The sunspot number is 19
  • The ISS makes the following visible evening passes this week:
    Monday: 21:58, W to E, max 89° and 23:35, W to S, max 49°
    Tuesday: 22:48, W to SE, max 53°
    Wednesday: 22:00, W to ESE, max 68° and 23:37, W to SSW, max 21°
    Thursday: 22:49, W to SSE, max 29°
    Friday: 22:02, W to SE, max 39°
    Saturday: 22:52, WSW to SSW, max 15°
    Sunday: 22:04, W to SSE, max 21°

Week of 17th May

  • Astronomical twilight ends at 00:02 BST at the beginning of the week, but by the end of the week, here at a latitude of 51° North, the Sun will no longer sink more than 18° below the horizon, meaning that astronomical twilight does not end. We will not experience astronomical darkness again until the 21st July
  • Mercury reaches greatest elongation east this week on Monday, placing it at its greatest separation from the Sun. Look for the planet low to the west-northwestern horizon just after sunset
  • The waxing Moon provides a good target this week, where plenty of surface detail can be observed, especially along the Terminator – the line separating night and day on the Moon
  • The Moon is First Quarter on Wednesday
  • The Sun currently has two active regions, AR 2822 and AR 2823. The sunspot number is 24
  • The ISS makes the following visible evening passes this week:
    Monday: 22:40, WSW to E, max 64°
    Tuesday: 21:56, SW to E, max 49° and 23:29, W to E, max 85°
    Wednesday: 22:41, W to E, max 89°
    Thursday: 21:54, WSW to E, max 78° and 23:31, W to E, max 89°
    Friday: 22:43, W to E, max 84°
    Saturday: 21:56, W to E, max 85° and 23:33, W to ESE, max 68°
    Sunday: 22:45, W to ESE, max 82°

Week of 10th May

  • Astronomical twilight ends at 23:34 BST at the beginning of the week and at 00:02 BST by the end of the week
  • On Thursday, the very thin, 1.8 days old, waxing Crescent Moon will be in conjunction with Mercury (mag +0.1), separated by about 2.5°. Look at around 14° altitude above the west-northwest horizon at about 21:00 BST, after sunset. You will also find Venus (-3.9) lower down, just above the horizon
  • On Sunday, Mercury will reach its highest point in the sky for this apparition, sitting at an altitude of 16° at 21:00 BST
  • The Moon is New on Tuesday
  • The Sun currently has one active region, AR 2822. The sunspot number is 17
  • The ISS makes the following visible evening passes this week:
    Friday: 21:51, SSE to ESE, max 13° and 23:25, SW to E, max 49°
    Saturday: 22:38, SW to E, max 36°
    Sunday: 21:51, SSW to E, max 26° and 23:27, WSW to E, max 78°

Week of 3rd May

  • Astronomical twilight ends at 23:07 BST at the beginning of the week and at 23:30 BST by the end of the week
  • The Eta-Aquariid meteor shower peaks on Thursday. Best prospects for observing inceased meteor numbers are in the early pre-dawn hours, when the Zenithal Hourly Rate is expected to be around 30-40. This meteor shower is created by debris deposited by comet 1P/Halley
  • Mercury appears low to the northwestern horizon shortly after sunset this week. On Tuesday, look at an altitude of about 9° and azimuth of 290° at around 21:15 BST, to find the planet shining at mag -0.8 just to the east of the Pleiades (+1.5). Take great care to avoid the glare of the Sun when looking for Mercury at sunset
  • At the start of the week the Waning Moon will appear in close proximity to Saturn (mag +0.7) and Jupiter (-2.2) in the southeastern pre-dawn sky
  • The Moon is Last Quarter on Monday
  • The Sun currently has one active region, AR 2818 and one emerging region on the oncoming limb that may develop into an active regtion. The sunspot number is 11
  • There are no visible ISS evening passes this week

April 2021 What’s Up!

Week of 26th April

  • Astronomical twilight ends at 22:44 BST at the beginning of the week and at 23:04 BST by the end of the week
  • On Tuesday the Moon reaches perigee, the closest point to Earth along its orbit. It will be at a distance of about 357,000 km with an angular size of 33.42 arcminutes, compared to its average size of 31.07 arcminutes. Perigee coincides with the full Moon, making it a ‘super Moon’, the first of three this year
  • The Moon is Full on Tuesday – the Super Pink Moon. Named ‘Super’ as it is a super Moon and ‘Pink’ after the early seasonal arrival of a species of wildflower in northern Native American culture
  • The Sun currently has multiple active regions, AR 2816, 2818, 2819 and 2820. The sunspot number is 62. There is a significant increase in activity so far this year compared to 2020
  • There are no visible ISS evening passes this week

Week of 19th April

  • Astronomical twilight ends at 22:24 BST at the beginning of the week and at 22:41 BST by the end of the week
  • The Lyrid meteor shower peaks on Thursday afternoon. Look out for increased meteor activity on both Wednesday and Thursday nights. The predicted Zenithal Hourly Rate is only 18, so don’t expect an intense display and viewing will be further hampered by the waxing Gibbous Moon. Hopefully the Radio Meteor Detector will pick up the increased activity. The Lyrid meteors are created by debris left behind by comet C/1861 G1 (Thatcher)
  • The Moon is First Quarter on Tuesday
  • The Sun currently has two active regions, AR 2814 and AR 2816. The sunspot number is 28. Recent data on sunspot count and solar activity suggest that the new Solar Cycle 25 is intensifying more quickly than originally predicted and the peak could be in 2024 rather than 2025
  • There are no visible ISS evening passes this week

Week of 12th April

  • Astronomical twilight ends at 22:05 BST at the beginning of the week and at 22:21 BST by the end of the week
  • On Saturday the 27% waxing Crescent Moon will appear close to Mars, with a separation of just under 4°. Look in the West after sunset to find the pair
  • The Moon is New on Monday
  • The Sun currently has no visible active regions. The spotless stretch is 4 days
  • There are no visible ISS evening passes this week

Week of 5th April

  • Astronomical twilight ends at 21:48 BST at the beginning of the week and at 22:03 BST by the end of the week
  • For the early risers, look low to the southeastern horizon from around 05:30 BST for about an hour before sunrise to find the waning Crescent Moon. On Tuesday morning it will be in conjunction with Saturn (mag +0.8) and on Wednesday morning it will be in conjunction with Jupiter (-2.1)
  • The Moon is a waning Crescent all this week
  • The Sun has one emerging potential active region in the Northern Hemisphere. It has been increasingly active so far this year, with only 36 spotless days, that being 38%; compare this to 57% spotless days last year and 77% the year before
  • There are no visible ISS evening passes this week

March 2021 What’s Up!

Week of 29th March

  • Astronomical twilight ends at 21:33 BST at the beginning of the week and at 21:46 BST by the end of the week
  • As the Moon wanes this week, the evenings give an opportunity for a spot of galaxy hunting. Use binoculars, or better a small telescope, to find Markarian’s Chain – a string of galaxies including M84 (mag +9.0) and M86 (+8.8) on the border of Virgo. Move up to Ursa Major to find Messier 51, The Whirlpool Galaxy (+7.9), about 3° below the end of the Plough’s handle. Two clusters worth seeking out are M3 (+6.2), a globular cluster in Canes Venatici and M44, The Beehive Cluster (+3.1), a wonderful open cluster in Cancer
  • The Moon is Last Quarter on Sunday
  • The Sun has one active region, AR 2812. The sunspot number is 11
  • The ISS makes the following evening passes this week:
    Monday: 20:24, W to ESE, max 86° and 22:01, W to WSW, max 29°
    Tuesday: 21:13, W to SSE, max 44°
    Wednesday: 20:26, W to ESE, max 58° and 22:03, W to SW, max 16°
    Thursday: 21:16, W to S, max 23°
    Friday: 20:28, W to SE, max 32°
    Saturday: 21:19, WSW to SSW, max 11°
    Sunday: 20:30, W to S, max 17°

Week of 22nd March

  • Astronomical twilight ends at 20:18 UT at the beginning of the week and at 21:31 BST by the end of the week
  • British Summer Time starts on Sunday when the clocks ‘spring forwards’ one hour at 01:00 UT to become 02:00 BST
  • A new nova has been observed in Cassiopeia and it has brightened rapidly from mag +9.6 to +7.5, so can be seen in binoculars. It is located about 5° east of the star Caph (Beta Cassiopeiae), the easternmost star of the familiar W asterism in Cassiopeia. Follow a line from Shedar (Alpha Cass.) to Caph and extend it the same distance again out towards the open cluster M52 and you should be able to locate the nova. Follow its progress over the coming weeks as it dims
  • The Moon is Full on Sunday
  • The Sun has one active region, AR 2810. The sunspot number is 12
  • The ISS makes the following evening passes this week:
    Monday: 20:05, WSW to E, max 73° and 21:42, W, max 13°
    Tuesday: 19:18, WSW to E, max 58° and 20:55, W, max 45°
    Wednesday: 20:07, W to E, max 87° and 21:44, W, max 14°
    Thursday: 19:20, WSW to E, max 86° and 20:57, W, max 48°
    Friday: 20:09, W to E, max 86° and 21:46, W, max 14°
    Saturday: 19:22, W to E, max 84° and 20:59, W to WSW, max 43°
    Sunday: 21:11, W to ESE, max 74° and 22:48, W, max 12°

Week of 15th March

  • Astronomical twilight ends at 20:04 UT at the beginning of the week and at 20:16 UT by the end of the week
  • On Friday evening, the waxing crescent Moon will be in conjunction with Mars, separated by just over 2°. The pair will make a fine sight between the Hyades and Pleiades clusters
  • The Vernal or Spring Equinox is on Saturday. At about 09:22 UT the Sun will cross the ecliptic, heading North, it will have a declination of 00° and a Right Ascension of 00h. We will enjoy almost exactly 12 hours of day and 12 hours of night; the Sun will rise from a point on the horizon due East and set at a point due West. The position of the Sun at the Vernal Equinox is also known as the First Point of Aries; however, these days the Sun is in the constellation of Pisces at this time, due to the precession of the Earth’s axis. The Vernal Equinox marks the first day of spring
  • The Moon is First Quarter on Sunday
  • The Sun has one active region, AR 2808. The sunspot number is 12
  • The ISS makes the following evening passes this week:
    Thursday: 20:02, SSW to S, max 18°
    Friday: 19:15, S to ESE, max 16° and 20:51, WSW to SW, max 19°
    Saturday: 20:03, SW to SSE, max 44°
    Sunday: 19:16, SW to E, max 32° and 20:53, WSW to WSW, max 35°

Week of 8th March

  • Astronomical twilight ends at 19:51 UT at the beginning of the week and at 20:02 UT by the end of the week
  • This is the week to attempt the Messier Marathon. It is possible to observe all 110 objects of the famous late 18th Century catalogue compiled by Charles Messier in one night at this time of year. It is best attempted around the New Moon. Stamina is required as the session starts immediately after sunset and continues through till dawn. If you do have a go, can you beat the 96 Messier objects spotted from the MCBO last year? Good luck!
  • The Moon is New on Saturday
  • The Sun has two active regions, AR 2806 and AR 2807. The sunspot number is 23
  • There are no visible evening ISS passes this week

Week of 1st March

  • Astronomical twilight ends at 19:39 UT at the beginning of the week and at 19:49 UT by the end of the week
  • Watch as Mars (mag +1.0) passes between the Pleiades and the Hyades this week. On Thursday it will be closest to the Pleiades, separated by only about 2.5°
  • For the early risers on Friday morning, at around 06:30 UT Jupiter (-2.0) and Mercury (+0.2) will rise together in the southeast. They will be separated by just 19 arc minutes
  • Mercury reaches greatest elongation west on Saturday
  • The Moon is Last Quarter on Saturday
  • After a busy week on the surface of the Sun, there is just one active region (AR 2804) making its way around the off-going limb. The sunspot number is 14
  • There are no visible evening ISS passes this week

 

February 2021 What’s Up!

Week of 22nd February

  • Astronomical twilight ends at 19:26 UT at the beginning of the week and at 19:37 UT by the end of the week
  • Following the initial success of all three Martian missions, study Mars yourself this week as the planet remains well placed in our evening sky. It is in the southwest at an altitude of around 50°, shining at mag +0.8 and it sets at around 01:00 UT. Track its progress towards the Pleiades over the coming week
  • The Moon is Full on Saturday – The Snow Moon
  • The Sun currently has one active region, AR 2803. The sunspot number is 12
  • There are no visible evening ISS passes this week

Week of 15th February

  • Astronomical twilight ends at 19:15 UT at the beginning of the week and at 19:25 UT by the end of the week
  • On Thursday evening, NASA’s Perseverance rover is due to touch down in the Jezero Crater on Mars soon after 19.15 UT. Go to the NASA website to watch a live stream of the event
  • Also on Thursday, the waxing crescent Moon (mag -9.2) will be in conjunction with Mars (+0.8), appearing less than 5° apart in the sky
  • The Moon is First Quarter on Friday
  • The Sun currently has no sunspots. The spotless stretch is 10 days
  • There are no visible evening ISS passes this week

Week of 8th February

  • Astronomical twilight ends at 19:03 UT at the beginning of the week and at 19:13 UT by the end of the week
  • This week is Star Count, an initiative run by CPRE (Campaign to Protect Rural England) to measure the levels of light pollution across the country. The public is asked to count the number of stars visible within the four corner stars of Orion and submit their finding along with location to the survey. Why not get involved and make your own Star Count observation? Check the CPRE Website for full details
  • Destination Mars – three separate missions to Mars will arrive at the red planet during February. The first two, UAE’s Hope probe and China’s Tianwen-1 orbiter, should arrive this week. The third, NASA’s Mars 2020 mission, is scheduled to arrive later this month on the 18th
  • The Moon is New on Thursday
  • The Sun currently has no sunspots. The spotless stretch is 3 days
  • There are no visible evening ISS passes this week

Week of 1st February

  • Astronomical twilight ends at 18:52 UT at the beginning of the week and at 19:02 UT by the end of the week
  • Mars is perhaps the highlight of this week’s night sky. Find the ‘Red Planet’ in the southwest through the evening, shining at mag +0.5. Look about 6° further west along the ecliptic to spot Uranus (mag +5.8)
  • With a waning Moon, this is the perfect time to hunt down some of the fainter objects, e.g. M1, the Crab Nebula, in Taurus (mag +8.4) or perhaps even M76, the Little Dumbbell Nebula, in Perseus, though that is a serious challenge as at only 3 arcminutes in apparent size and mag +10, it is one the faintest objects in Messier’s list
  • The Moon is Last Quarter on Thursday
  • The Sun currently has no sunspots. The spotless stretch is 3 days
  • The ISS makes visible evening passes this week as follows:Monday: 17:51, W to ESE, max 78° & 19:28, W to SW, max 26°
    Tuesday: 18:41, W to SSE, max 36°
    Wednesday: 17:53, W to SE, max 48° & 19:31, WSW to SSW, max 13°
    Thursday: 18:43, W to S, max 19°
    Friday: 17:56, W to SSE, max 26°
    Sunday: 17:59, WSW to SSW, max 13°

January 2021 What’s Up!

Week of 25th January

  • Astronomical twilight ends at 18:42 UT at the beginning of the week and at 18:51 UT by the end of the week
  • On Wednesday, Mercury (mag -0.1) reaches its highest point in the evening sky at 13° altitude. It will be visible in the southwest after sunset (16:48 UT) until it sets at 18:30 UT. Take care if using binoculars
  • The Moon is Full on Thursday
  • The Sun currently has three visible active regions (AR 2797, AR 2798 & AR 2799). The sunspot number is 34
  • The ISS makes visible evening passes this week as follows:

    Monday: 18:32, WSW to E, max 82° & 20:09, W, max 12°
    Tuesday: 17:45, WSW to E, max 68° & 19:22, W, max 38°
    Wednesday: 18:34, W to E, max 84° & 20:11, W, max 12°
    Thursday: 17:47, W to E, max 88° & 19:24, W, max 40°
    Friday: 18:36, W to E, max 89° & 20:13, W, max 12°
    Saturday: 17:49, W to E, max 85° & 19:26, W to WSW, max 38°
    Sunday: 18:38, W to SE, max 63° & 20:16, W, max 11°

Week of 18th January

  • Astronomical twilight ends at 18:32 UT at the beginning of the week and at 18:40 UT by the end of the week
  • Mars and Uranus appear close together this week, easily fitting in to the field of view of a pair of 10×50 binoculars. On Wednesday they will be at their closest, with a separation of just 1° 37 minutes and on Thursday they will be joined by the waxing Gibbous Moon, just a few degrees away.
  • Mercury reaches greatest elongation east on Sunday and will be visible sinking from about 10° above the southwestern horizon for the hour after sunset. Take care if using binoculars
  • The Moon is First Quarter on Wednesday
  • The Sun has one small active region (AR 2796) currently visible. The sunspot number is 15
  • The ISS makes visible evening passes this week as follows:

    Tuesday: 18:29, S to SSE, max 14°
    Wednesday: 19:16, SW to SSW, max 21°
    Thursday: 18:29, SSW to E, max 29°
    Friday: 17:41, SSW to SE, max 21° & 19:17, WSW to WSW, max 33°
    Saturday: 18:29, SW to ESE, max 52° & 20:06, W to W, max 12°
    Sunday: 17:42, SW to E, max 39° & 19:18, W to W, max 39°

Week of 11th January

  • Astronomical twilight ends at 18:23 UT at the beginning of the week and at 18:31 UT by the end of the week
  • On Thursday, look to the southwest just after sunset to see the very young, 3% waxing crescent Moon almost in line with Mercury (mag. -0.9), Jupiter (-1.9) and Saturn (0.6). You will need to be quick as Saturn sets at 17:08 UT, just 42 minutes after sunset. Take care when looking towards the setting Sun, especially if using binoculars
  • The Moon is New on Wednesday
  • The Sun has no visible active regions now. The spotless stretch is 7 days
  • There are no visible ISS evening passes this week

Week of 4th January

  • Astronomical twilight ends at 18:15 UT at the beginning of the week and at 18:22 UT by the end of the week
  • Following the Great Conjunction, Mercury approaches the two Gas Giants in the evening sky on Saturday. The three planets will form a triangle covering only about 3° in the southwestern sky. Look at around 16:20 UT, about half an hour after sunset, to see Mercury (mag -0.9) only about 5° above the horizon, with Saturn (0.6) 1.5° away at about 7° altitude and Jupiter (-1.9) another 2° away about 8° above the horizon
  • The Moon is Last Quarter on Wednesday
  • The Sun currently has two active regions, AR 2794 & AR 2795, both very close to the off going limb – the sunspot number is 22
  • There are no visible ISS evening passes this week