What’s Up

Week of 26th September

• Astronomical twilight ends at 20:49 BST at the beginning of the week and at 20:34 BST by the end of the week
• Jupiter reaches opposition on Monday, the point in its orbit when it will be opposite the Sun from Earth. This is the best time to view the planet as it will appear largest and brightest in our sky as it is also at perigee, its point of closest approach to Earth. Jupiter will be 3.95 AU (591 million km) from Earth (its closest in 59 years!), with an apparent size of 49 arcseconds and a magnitude of -2.9. Look for the brightest object in our southern sky at an altitude of about 38° by midnight
• The two lunar clair-obscur effects known as the lunar X and V will be visible in the early evening of Sunday, look along the terminator to find them. They are caused by sunlight catching certain parts of crater edges and higher regions
• The Moon is Waxing Crescent all week
• The Sun currently has six active regions: AR 3102, 3105, 3107, 3108, 3109 & 3110. The sunspot number is 128
• The ISS makes the following visible evening passes this week:
  Monday 20:19, W to ESE, max 87° and 21:56, W, max 16°
  Tuesday 19:30, W to E, max 86° and 21:07, W to SW, max 43°
  Wednesday 20:18, W to SE, max 62° and 21:56, W to WSW, max 12°
  Thursday 19:30, W to ESE, max 77° and 21:07, W to SW, max 25°
  Friday 20:18, W to SSE, max 36°
  Saturday 19:29, W to SE, max 49° and 21:07, WSW to SW, max 13°
  Sunday 20:17, W to S, max 19°

Week of 19th September

• Astronomical twilight ends at 21:07 BST at the beginning of the week and at 20:51 BST by the end of the week
• The Autumn Equinox occurs at 01:58 BST on Friday. This is the point when the Sun crosses the celestial equator decreasing in declination. As the name suggests, we will enjoy an almost exactly equal day and night length of 12 hours and the event marks the start of autumn for the northern hemisphere. The Sun will rise due East and set due West, one of only two days in the year when this happens
• Jupiter is brilliant in our evening and night sky at magnitude -2.9, outshone only by the Moon. This is an excellent time to observe the planet as it moves towards opposition. Use binoculars or a telescope to observe surface detail on the planet and enjoy the dance of its four Galilean moons as they orbit. Jupiter currently rises at around 19:15 BST, culminates at around 01:30 BST, reaching a maximum altitude of about 39°, and sets by about 07:30 BST
• The Moon is New on Sunday
• The Sun currently has three active regions: AR 3100, 3102 & 3103. The sunspot number is 76
• The ISS makes the following visible evening passes this week:
  Monday 21:09, WSW to SE, max 76°
  Tuesday 20:21, WSW to E, max 60° and 21:57, W, max 26°
  Wednesday 21:09, W to ENE, max 86°
  Thursday 20:20, WSW to E, max 86° and 21:57, W, max 24°
  Friday 19:31, S to WSW to E, max 73° and 21:08, W to NW, max 85°
  Saturday 20:20, W to E, max 84° and 21:56, W, max 21°
  Sunday 19:31, W to E, max 87° and 21:08, W to WSW, max 67°

Week of 12th September

• Astronomical twilight ends at 21:26 BST at the beginning of the week and at 21:09 BST by the end of the week
• Neptune reaches opposition on Friday, when it lies opposite the Sun in the sky and will be at perigee, the closest point to Earth in its orbit. It is magnitude +7.8, so binoculars or a telescope will be required to observe the planet. Find it about 10° west of Jupiter in the south. It culminates at around 01:00 BST, so is well placed through the late evening
• The planets are dominating our southern evening sky with Saturn (+0.4) furthest west, followed by Neptune (+7.8), Jupiter (-2.9), Uranus (+5.7) and finally Mars (-0.4) which rises at around 22:00 BST
• The Moon is Last Quarter on Saturday
• The Sun currently has eight active regions: AR 3092, 3094, 3096, 3097, 3098, 3099, 3100 & 3101. The sunspot number is 122
• The ISS makes the following visible evening passes this week:
  Thursday 21:10, SSW to S, max 19°
  Friday 20:22, S to ESE, max 18° and 21:58, WSW, max 16°
  Saturday 21:09, SW to S, max 46°
  Sunday 20:21, SW to E, max 34° and 21:57, W, max 25°

Week of 5th September

• Astronomical twilight ends at 21:46 BST at the beginning of the week and at 21:29 BST by the end of the week
• Unfortunately, NASA’s attempted launch of Artemis 1 was not successful last week and further launch attempts are not likely until next month at the earliest
• The waxing Gibbous Moon will make a close approach to Saturn (+0.4) on Thursday, when they will be separated by just 6°. Jupiter (-2.9) is rising ever higher in our evening sky, while Neptune (+7.8) lies to its west and Uranus (+5.7) to the east. Mars (-0.2) is now rising at around 22:30 BST as it moves towards opposition in December
• The Moon is Full on Saturday – the Harvest Moon
• The Sun currently has four active regions: AR 3089, 3092, 3093 & 3094. The sunspot number is 68
• There are no visible evening ISS passes this week

Week of 29th August

• Astronomical twilight ends at 22:07 BST at the beginning of the week and at 21:49 BST by the end of the week
• On Monday, NASA are set to launch Artemis 1, the unmanned test flight for the return to the Moon mission. Lift off is scheduled for 12:33 UT and the mission is due to last 42 days. The Orion crew capsule will orbit the Moon for a week, approaching to about 62 miles of the lunar surface. Follow the mission’s progress online
• Planets Saturn (+0.3), Jupiter (-2.9) and Mars (-0.1) are lining up across our night sky. Little moonlight makes this week a perfect time to observe them
• The Moon is First Quarter on Saturday
• The Sun currently has five active regions: AR 3085, 3086, 3087, 3088 & 3089. The sunspot number is 84
• There are no visible evening ISS passes this week

Week of 22nd August

• Astronomical twilight ends at 22:28 BST at the beginning of the week and at 22:10 BST by the end of the week
• Minor planet 4 Vesta reaches opposition on Tuesday. It can be found about 10° above the southeastern horizon at around 23:00 BST between Aquarius and Capricorn. It presents an observing challenge at magnitude +6.0, but repeated observations through the week to see its movement against the background stars will confirm your observation
• Saturn (+0.3) and Jupiter (-2.8) are visible in our evening sky, with Mars (0.0) not far behind, rising at around 23:00 BST
• The Moon is New on Saturday
• The Sun currently has four active regions: AR 3078, 3081, 3082 & 3084. The sunspot number is 56
• There are no visible evening ISS passes this week

Week of 15th August

• Astronomical twilight ends at 22:51 BST at the beginning of the week and at 22:32 BST by the end of the week
• The Gas Giants, Saturn and Jupiter, are in our evening sky now, with Saturn culminating at 01:16 BST and Jupiter rising at 21:49 BST. Look in the southeastern sky to spot the two planets
• Mars is further East, rising at 23:30 BST
• The Moon is Last Quarter on Friday
• The Sun currently has eight active regions: AR 3071, 3074, 3076, 3077, 3078, 3079, 3080 & 3081. The sunspot number is 116
• There are no visible evening ISS passes this week

Week of 8th August

• Astronomical twilight ends at 23:16 BST at the beginning of the week and at 22:55 BST by the end of the week
• The Perseid meteor shower peaks on Friday. Under dark skies the Perseids can produce around 100 meteors per hour, but this year the Full Moon coincides with the peak and will drown out all but the brightest meteors, so expect a much lower ZHR. The Perseids are caused by Earth passing through debris deposited by comet 109P/Swift-Tuttle
• Saturn reaches opposition on Sunday, the point in its orbit when it lies directly opposite the Sun from Earth. It will appear larger and brighter than usual at 18.8 arcseconds and magnitude +0.3, making this the best time to observe the planet
• The Moon is Full on Friday
• The Sun currently has five active regions: AR 3068, 3071, 3072, 3073 & 3074. The sunspot number is 69
• There are no visible evening ISS passes this week

Week of 1st August

• Astronomical twilight ends at 23:43 BST at the beginning of the week and at 23:20 BST by the end of the week
• As Saturn approaches opposition on the 14th August, this is a good time to start observing the ringed gas giant. It rises at around 21:15 BST and culminates at around 02:00 BST, so is well placed for evening observing in our southeastern sky. It is quite low to the horizon at around 16°. Note how the rings appear to brighten each night as it approaches opposition
• The Moon is First Quarter on Friday
• The Sun currently has two active regions: AR 3062 & 3068. The sunspot number is 27
• There are no visible evening ISS passes this week

Week of 25th July

• Astronomical twilight ends at 00:22 BST at the beginning of the week and at 23:47 BST by the end of the week
• The Southern Delta Aquariid meteor shower peaks at the end of this week on Friday night. The shower’s ZHR is around 20 meteors per hour. This week’s dark skies will be favourable for spotting meteors. The radiant is close to the star Skat, Delta Aquarii, which is low to our southeastern horizon. The shower is caused by debris left by comet P/2008 Y12 (SOHO)
• With little moonlight this week, it is an ideal time to observe double stars. Two interesting targets are in the Summer Triangle: Albireo, the beak of Cygnus the Swan, is an easily split beautiful indigo and gold double, while Epsilon Lyrae is a fascinating and more challenging multiple star system consisting of two double stars, hence its popular name the Double Double
• The Moon is New on Thursday
• The Sun currently has seven active regions: AR 3057, 3059, 3060, 3062, 3063, 3064 & 3065. The sunspot number is 96
• There are visible evening ISS passes this week as follows:
  Monday: 22:17, W to SE, max 52° & 23:54, WSW to SW, max 14°
  Tuesday: 23:06, W to SSW, max 21°
  Wednesday: 22:17, W to SSE, max 29°
  Friday: 22:17, WSW to S, max 15°

Week of 18th July

• Astronomical Darkness returns on the 21st July when astronomical twilight ends at 00:59 BST, with darkness lasting for 29 minutes. By the end of the week astronomical twilight ends at 00:29 BST and astronomical darkness will last for about an hour and a half
• On Wednesday, the dwarf planet Pluto reaches opposition. It is in the constellation of Sagittarius and lies about 13° above the southern horizon. It is very faint at only magnitude +14, making photography the best method of observation
• Saturn (mag +0.5) is visible in our evening sky, rising at 22:15 BST and lying about 15° above the southeastern horizon around midnight
• The Moon is Last Quarter on Wednesday
• The Sun currently has seven active regions: AR 3053, 3055, 3056, 3057, 3058, 3059 & 3060. The sunspot number is 153
• There are visible evening ISS passes this week as follows:
  Monday: 23:06, W to E, max 84°
  Tuesday: 22:17, W to E, max 89° & 23:54, W to ESE, max 78°
  Wednesday: 23:06, W to E, max 89°
  Thursday: 22:17, W to E, max 85° & 23:54, W to S, max 50°
  Friday: 23:06, W to ESE, max 65°
  Saturday: 22:17, W to ESE, max 80° & 23:54, W to SW, max 27°
  Sunday: 23:05, W to SSE, max 38°

Week of 11th July

• Astronomical twilight does not end until 21st July
• On Wednesday, the Moon will reach its Full phase shortly after passing perigee, making it a ‘supermoon’, the popular term for a Full Moon when the Moon is at a closer point to Earth in its elliptical orbit. Whilst the Moon will appear slightly larger and slightly brighter than normal, the difference is barely perceptible. What will be noticeable are the spring tides that will be particularly high for a few days around the Full Moon.
• The Moon is Full on Wednesday – the Buck Moon
• The Sun currently has five active regions: AR 3046, 3051, 3052, 3053 & 3055. The sunspot number is 89
• There are visible evening ISS passes this week as follows:
  Monday: 22:20, SSE to ESE, max 11° & 23:54, SW to E, max 43°
  Tuesday: 23:06, SW to E, max 31°
  Wednesday: 22:18, SSW to E, max 22° & 23:54, WSW to E, max 71°
  Thursday: 23:06, WSW to E, max 55°
  Friday: 22:18, SW to E, max 41° & 23:54, W to E, max 88°
  Saturday: 23:06, WSW to E, max 83°
  Sunday: 22:17, WSW to E, max 69° & 23:54, W to E, max 85°

Week of 4th July

• Astronomical twilight does not end until 21st July
• The Earth reaches aphelion on Monday, the furthest point from the Sun in its annual orbit at a distance of 1.0167 AU. The elliptical orbit of the Earth sees a 3% variance over the year, but despite the Sun being at its smallest in the sky and Earth receiving the lowest amount of radiation, the difference is imperceptible to most of us
• Saturn (magnitude +0.5) is now an evening object, rising at 23:15 BST on Monday. Jupiter (-2.5) and Mars (+0.4) are not too far behind, both visible in the southeast soon after midnight
• The Moon is First Quarter on Thursday
• The Sun currently has four active regions: AR 3040, 3046, 3047 & 3048. The sunspot number is 57
• There are visible evening ISS passes this week as follows:
  Saturday: 23:59, ESE to E, max 17°
  Sunday: 23:11, ESE to E, max 12°

Week of 27th June

• Astronomical twilight does not end until 21st July
• With no moonlight, this week is optimal for deep sky observing. Interesting targets include: Globular Clusters such as M13 and M92 in Hercules, the Coathanger asterism in Vulpecula, the Ring Nebula (M57) in Lyra, the double star Albireo in Cygnus as well as the arc of the Milky Way across our summer sky – a treat by naked eye or to explore with binoculars
• The Moon is New on Wednesday
• The Sun currently has two active regions: AR 3038 & 3040. The sunspot number is 31
• There are no visible evening ISS passes this week

Week of 20th June

• Astronomical twilight does not end until 21st July
• The Summer Solstice is on Tuesday, when the Sun will reach its most northerly point in the sky at a declination of +23.5°. The exact time of the Solstice will be 10:08 BST. Tuesday will be the longest day in the Northern Hemisphere, with sunrise at 04:50 BST and sunset at 21:27 BST. The solstice marks the astronomical start of summer
• The Waning Moon passes the bright morning planets throughout this week, from west to east: Saturn (+0.6), Jupiter (-2.4), Mars (+0.5) and Venus (-3.9)
• The Moon is Last Quarter on Tuesday
• The Sun currently has nine active regions: AR 3030, 3031, 3032, 3033, 3034, 3035, 3037, 3038 & 3039. The sunspot number is 145
• There are no visible evening ISS passes this week

Week of 13th June

• Astronomical twilight does not end until 21st July
• All eight planets of the solar system are visible in our morning sky this week, from east to west: Mercury (mag +0.6), Venus (-3.9), Uranus (+5.8), Mars (+0.6), Jupiter (-2.3), Neptune (+7.9), Saturn (+0.7) and finally, look around to spot Earth! Sunrise is at about 04:50 BST all week, so an early rise is required for this observing challenge
• Mercury reaches Greatest Western Elongation on Thursday, with about 23° of apparent separation from the Sun. This is the ideal time to spot the innermost planet of the solar system; look to the east-north-east at about 8° above the horizon in the half hour before sunrise
• The Moon is Full on Tuesday – the Strawberry Super Moon, so named as Full Moon occurs at the same time as perigee, when the Moon is closest to Earth in its orbit. Whilst the Moon will be slightly larger and slightly brighter than at apogee, to the extent of about 14%, this will be imperceptible. However, it will appear largest as it rises on Tuesday evening at 22:08 BST when it is close to the horizon, creating the Moon illusion
• The Sun currently has three active regions: AR 3029, 3030 & 3031. The sunspot number is 41
• There are no visible evening ISS passes this week

Week of 6th June

• Astronomical twilight does not end until 21st July
• The four naked eye planets line up in our morning sky this week in distance order from east to west: Venus (magnitude -4.0), Mars (+0.6), Jupiter (-2.3) and Saturn (+0.7). The two Ice Giants are also visible, but you will need binoculars, with Neptune (+7.9) about 9° west of Jupiter and Uranus (+5.9) about 4° east of Venus
• The Moon is First Quarter on Tuesday
• The Sun currently has six active regions: AR 3023, 3024, 3026, 3027, 3028 & 3029. The sunspot number is 75
• There are no visible evening ISS passes this week

Week of 30th May

• Astronomical twilight does not end until 21st July
• No Moon this week makes it ideal for deep sky observing, though a late start at around 23:00 BST will be required. Ideal targets include four Globular Clusters: M3 in Canes Venatici, M5 in Serpens, M13 (the Great Hercules Cluster) and M92 both in Hercules. They are all around magnitude +6 and are easily found in binoculars or a small telescope
• The Moon is New on Monday
• The Sun currently has three active regions: AR 3021, 3023 & 3024. The sunspot number is 34
• There are no visible evening ISS passes this week

Week of 23rd May

• Astronomical twilight ends at 00:52 BST on Monday and after that we no longer enter astronomical darkness as the Sun does not reach 18° below our northern horizon; nautical darkness is as dark as it gets until 21st July
• The Sun is ever more active and makes a superb object to observe *SAFELY* (with the necessary filters or projection techniques, of course!) as increasing numbers of sunspots are developing
• We are entering the season of Noctilucent Clouds. Keep an eye out for these high level pearlescent shifting cloud displays in the hours of darkness above our northern horizon
• The waning Moon passes by the four planets in our morning sky through this week, from west to east: Saturn (+0.8), Mars (+0.7), Jupiter (mag -2.2) and Venus (-4.0)
• The Moon is Waning Crescent all week
• The Sun currently has seven active regions: AR 3010, 3011, 3014, 3015, 3016, 3017 & 3019. The sunspot number is 110. So far this year there have been zero spotless days!
• There are multiple visible evening ISS passes this week as follows:
  Monday: 22:21, W to ESE, max 83° & 23:58, W to SW, max 29°
  Tuesday: 23:09, W to SSE, max 41°
  Wednesday: 22:21, W to SE, max 55° & 23:59, WSW to SW, max 15°
  Thursday: 23:10, W to SSW, max 22°
  Friday: 22:22, W to SSE, max 30°
  Saturday: 23:12, WSW to SSW, max 11°
  Sunday: 22:23, WSW to S, max 16°

Week of 16th May

• Astronomical twilight ends at 00:01 BST at the start of the week and at 00:37 BST by the end of the week
• On Monday morning there is a total lunar eclipse. The partial eclipse starts at 03:27 BST and the total eclipse starts at 04:29 BST, with maximum eclipse at 05:11 BST. Unfortunately, we will miss the end of the eclipse as the Moon sets at 05:17 BST. Look low to the western horizon to follow this event
• Look to the southeastern horizon just before sunrise to see four planets, from east to west: Venus (-4.0), Jupiter (mag -2.2), Mars (+0.8) and Saturn (+0.8)
• The Moon is Full on Monday – the Super Blood Flower Moon and last Quarter on Sunday
• The Sun currently has five active regions: AR 3006, 3007, 3010, 3011 & 3013. The sunspot number is 105
• There are multiple visible evening ISS passes this week as follows:
  Monday: 23:06, WSW to E, max 78°
  Tuesday: 22:18, WSW to E, max 64° & 23:55, W to E, max 84°
  Wednesday: 23:06, W to E, max 85°
  Thursday: 22:18, W to E, max 88° & 23:55, W to ESE, max 82°
  Friday: 23:06, W to E, max 88°
  Saturday: 22:18, W to E, max 84° & 23:54, W to SSE, max 55°
  Sunday: 23:06, W to ESE, max 71°

Week of 9th May

• Astronomical twilight ends at 23:29 BST at the start of the week and at 23:56 BST by the end of the week
• Four planets continue their line up in our morning southeastern sky, from east to west: Venus (-4.0), Jupiter (mag -2.2), Mars (+0.8) and Saturn (+0.8)
• The Moon is First Quarter on Monday
• The Sun currently has three active regions: AR 3001, 3004 & 3006. The sunspot number is 66
• There are multiple visible evening ISS passes this week as follows:
  Friday: 22:18, SSW to SSE, max 19° & 23:53, WSW to E, max 14°
  Saturday: 21:30, S to ESE, max 13° & 23:05, SW to E, max 49°
  Sunday: 22:17, SW to E, max 36° & 23:53, W to E, max 89°

Week of 2nd May

• Astronomical twilight ends at 23:03 BST at the start of the week and at 23:25 BST by the end of the week
• Our morning sky is a feast of planets, with (from east to west): Venus (-4.1), Jupiter (mag -2.1), Mars (+0.9) and Saturn (+0.9) creating a line over our southeastern horizon in the pre-dawn hour
• The Eta Aquarid meteor shower peaks on Thursday morning. It has a broad peak, so it is worth trying to spot an Eta Aquarid meteor on both Wednesday and Thursday nights. The shower’s radiant, in Aquarius, is low to our horizon, so it is not a very productive shower for the northern hemisphere, with a ZHR of around 30. It is more impressive in the southern hemisphere. The shower is produced by dust particles left behind by comet 1P/Halley
• The Moon is Waxing Crescent all week
• The Sun currently has four active regions: AR 2995, 2997, 2999 & 3001. The sunspot number is 50
• There are no visible evening ISS passes this week

Week of 25th April

• Astronomical twilight ends at 22:41 BST at the start of the week and at 23:00 BST by the end of the week
• The planets are lining up in the morning sky. Look just above the southeastern horizon shortly before sunrise to see (from east to west): Jupiter (mag -2.1), Venus (-4.1), Mars (+0.9) and Saturn (+0.9). The waning crescent Moon passes a few degrees below the planets through the course of the week
• Mercury (+0.4) reaches Greatest Eastern Elongation on Friday and will be visible about 11° above the western horizon after sunset
• On Sunday morning, Jupiter (-2.1) and Venus (-4.1) will be in conjunction, separated by less than half a degree – a fine sight for binoculars or a small telescope
• The Moon is New on Saturday
• The Sun currently has seven active regions: AR 2991, 2993, 2994, 2995, 2996, 2997 & 2998. The sunspot number is 118
• There are no visible evening ISS passes this week

Week of 18th April

• Astronomical twilight ends at 22:21 BST at the start of the week and at 22:38 BST by the end of the week
• The Lyrid meteor shower peaks on Friday evening. It is a relatively small shower with a zenithal hourly rate of only around 15 meteors. However, it can occasionally produce a much more active shower with a ZHR of up to 100, so it is worth keeping an eye out in case it does so this year! The radiant is in the constellation of Lyra and the shower’s parent body is comet C/1861 G1 (Thatcher)
• The Moon is Last Quarter on Saturday
• The Sun currently has six active regions: AR 2989, 2990, 2991, 2992, 2993 & 2994. The sunspot number is 78
• There are no visible evening ISS passes this week

Week of 11th April

• Astronomical twilight ends at 22:02 BST at the start of the week and at 22:18 BST by the end of the week
• The Moon is Full on Saturday – the Pink Moon
• This week’s Full Moon is also known as the Paschal Full Moon as it defines when Easter is celebrated – being on the first Sunday after the first Full Moon after the Vernal Equinox, which will be this Sunday
• The Sun currently has three active regions: AR 2978, 2983 & 2985. The sunspot number is 37
• There are no visible evening ISS passes this week

Week of 4th April

• Astronomical twilight ends at 21:46 BST at the start of the week and at 22:00 BST by the end of the week
• Tuesday morning sees a conjunction of Saturn (+0.9) and Mars (+1.0), when they will be separated by only 19 arc minutes. Venus (-4.3) is about 7° to the east. Look to the southeastern horizon just before sunrise
• Galaxy season is here! The area of sky between the tail of Leo, the bowl of Virgo and Coma Berenices is full of galaxies, including the elliptical galaxy M88 or Virgo A, the largest member of our own galaxy group, the Virgo Cluster. Galaxies generally appear as ‘faint fuzzy blobs’ in amateur instruments, understandable given their distance, M88 is 55 million light years away and has an apparent magnitude of +8.7, so you will need a dark night to spot it
• The Moon is First Quarter on Saturday
• The Sun currently has seven active regions: AR 2975, 2976, 2978, 2981, 2982, 2983 & 2984. The sunspot number is 118
• There are no visible evening ISS passes this week

Week of 28th March

• Astronomical twilight ends at 21:30 BST at the start of the week and at 21:43 BST by the end of the week
• On Monday morning, just before sunrise (at 06:51 BST), planets Venus (mag -4.3), Saturn (+0.9) and Mars (+1.1) appear close together about 9° above the southeastern horizon and are joined by the waning crescent Moon (-5.4)
• The Moon is New on Friday
• The Sun currently has three active regions: AR 2974, 2975 & 2976. The sunspot number is 48
• There are multiple visible evening ISS passes this week as follows:
  Monday 21:37, W to SSW, max 45°
  Tuesday 20:49, W to SE, max 60° and 22:26, W to WSW, max 14°
  Wednesday 21:38, W to SSW, max 25°
  Thursday 20:49, W to SSE, max 34°
  Friday 21:39, WSW to SSW, max 12°
  Saturday 20:51, W to S, max 12°

Week of 21st March

• Astronomical twilight ends at 20:16 UT at the start of the week and at 21:28 BST by the end of the week
• The clocks go forward one hour on Sunday; at 01:00 UT it will become 02:00 BST, the start of British Summer Time and daylight saving
• With the waning Moon and before the clocks change, this week is a good opportunity to enjoy the delights of Orion and the Winter Wreath as that portion of sky slips ever westwards. Meanwhile, the eastern sky, with Arcturus, the Spring Marker star rising, is home to a myriad of galaxies
• The Moon is Last Quarter on Friday
• The Sun currently has two active regions: AR 2965 & 2972. The sunspot number is 29
• There are multiple visible evening ISS passes this week as follows:
  Monday 19:45, WSW to E, max 59° and 21:28, W, max 19°
  Tuesday 18:58, SW to E, max 44° and 20:34, W, max 77°
  Wednesday 19:46, WSW to E, max 86° and 21:23, W, max 22°
  Thursday 18:58, WSW to E, max 73° and 20:35, W to NW, max 85°
  Friday 19:47, W to E, max 84° and 21:24, W, max 22°
  Saturday 18:59, W to E, max 87° and 20:36, W to SSW, max 74°
  Sunday 20:48, W to ESE, max 86° and 22:25, W, max 20°

Week of 14th March

• Astronomical twilight ends at 20:02 UT at the start of the week and at 20:14 UT by the end of the week
• The Spring Equinox is on Sunday, when we will enjoy almost exactly 12 hours of night and 12 hours of day. The Sun will rise exactly in the East and set exactly in the West. The actual moment that the Sun crosses the celestial equator moving from south to north is at 15:27 UT. This marks the first day of spring here in the northern hemisphere
• Venus reaches Greatest Western Elongation on Sunday, when it will be at its largest separation from the Sun, 46° apart. It will be shining brightly at magnitude -4.4 about 13° above the southeastern horizon at sunrise
• The Moon is Full on Friday – the Worm Moon
• The Sun currently has five active regions: AR 2960, 2964, 2965, 2966 & 2967. The sunspot number is 93
• There are multiple visible evening ISS passes this week as follows:
  Thursday 19:46, S to SSE, max 15°
  Friday 18:58, SSE to ESE, max 12° and 20:32, SW to SW, max 23°
  Saturday 19:45, SW to SE, max 33° and 21:21, WSW to WSW, max 13°
  Sunday 18:57, SSW to E, max 24° and 20:33, WSW to SW, max 52°

Week of 7th March

• Astronomical twilight ends at 19:49 UT at the start of the week and at 20:00 UT by the end of the week
• Leo, Virgo and Coma Berenices are well placed this week, ideal for exploration of their plethora of galaxies
• Early risers can spot Mars (mag +1.2) and Venus (-4.5) in the southeastern morning sky just before sunrise
• The Moon is First Quarter on Thursday
• The Sun currently has six active regions: AR 2955, 2957, 2958, 2960, 2961 & 2962. The sunspot number is 95
• There are no visible evening ISS passes this week

Week of 28th February

• Astronomical twilight ends at 19:36 UT at the start of the week and at 19:47 UT by the end of the week
• New Moon this week provides the perfect dark skies to attempt the Messier Marathon – try and spot all 110 Messier objects in one night!
• Mars (mag +1.3) and Venus (-4.6) grace our southeastern morning sky this week just before sunrise
• The Moon is New on Wednesday
• The Sun currently has two active regions: AR 2954 & 2955. The sunspot number is 22
• There are no visible evening ISS passes this week

Week of 21st February

• Astronomical twilight ends at 19:24 UT at the start of the week and at 19:35 UT by the end of the week
• On Sunday there is a morning gathering of solar system objects. Find the waning Crescent Moon close to Mars (mag +1.3), Venus (-4.6), Mercury (-0.1) and Saturn (+0.8). Look just above the southeastern horizon at around 07:00 UT, but avoid the rising Sun, especially if looking with binoculars
• With a waning Moon, this week’s dark evening skies will be ideal for deep sky hunting with binoculars; find two beautiful open clusters in Cancer: M44 – The Beehive Cluster (+3.1) and M67 (+6.9)
• The Moon is Last Quarter on Wednesday
• The Sun currently has four active regions: AR 2946, 2948, 2952 & 2953. The sunspot number is 51
• There are no visible evening ISS passes this week

Week of 14th February

• Astronomical twilight ends at 19:13 UT at the start of the week and at 19:23 UT by the end of the week
• On Wednesday, Mercury (mag 0.0) reaches greatest western elongation, making it appear at its highest altitude in our morning sky at about 8° above the southeastern horizon
• Look about 10° further to the west to spot Venus (-4.6) and Mars (+1.3) gracing our morning sky
• The Moon is Full on Wednesday – the Snow Moon
• The Sun currently has four active regions: AR 2939, 2940, 2941 & 2944. The sunspot number is 78
• There are no visible evening ISS passes this week

Week of 7th February

• Astronomical twilight ends at 19:01 UT at the start of the week and at 19:11 UT by the end of the week
• On Monday, the 6 day old, waxing crescent Moon (mag -7.1) will appear just 1° away from Uranus (+5.8) in the sky
• On Sunday, Venus (-4.6) will be at its highest altitude in the morning sky. Look about 16° above the southeastern horizon at around 07:30 UT, just before sunrise to spot the bright planet
• The Moon is First Quarter on Tuesday
• The Sun currently has four active regions: AR 2938, 2939, 2940 & 2941. The sunspot number is 91
• There are no visible evening ISS passes this week

Week of 31st January

• Astronomical twilight ends at 18:50 UT at the start of the week and at 19:00 UT by the end of the week
• Two comets are potential observing targets in the dark skies of the New Moon this week. Comet 19P/Borrelly is at mag +7.9 in Pisces and comet C/2019 L3 (ATLAS) is a trickier target at mag +12 in Gemini. A telescope and good seeing will be essential for success
• Mercury (+0.4) is at its highest altitude in the morning sky on Sunday. Look at an altitude of about 7° in the southeast at around 07:30 UT before sunrise. Venus will be shining brightly at mag -4.6 about 10° further west
• The Moon is New on Tuesday
• The Sun currently has four active regions: AR 2934, 2935, 2936 & 2937. The sunspot number is 74
• There are multiple evening ISS passes this week as follows:
  Monday: 18:04, W to ESE, max 72° and 19:41, W to WSW, max 21°
  Tuesday: 18:53, W to SSE, max 32°
  Wednesday: 18:04, W to SE, max 43° and 19:43, WSW to SSW, max 11°
  Thursday: 18:54, W to S, max 17°
  Friday: 18:05, W to SSE, max 23°
  Sunday: 18:07, WSW to SSW, max 12°

Week of 24th January

• Astronomical twilight ends at 18:40 UT at the start of the week and at 18:49 UT by the end of the week
• With a waning Moon giving dark evening skies, this is a good week to explore the Deep Sky delights of Orion. From star birth in The Orion Nebula (M42), to the ageing red supergiant, Betelgeuse and the hot supergiant double star, Alnitak, in Orion’s Belt
• The Moon is Last Quarter on Tuesday
• The Sun currently has two active regions: AR 2933 & 2934. The sunspot number is 22
• There are multiple evening ISS passes this week as follows:
  Monday: 17:14, SW to E, max 35° and 18:50, W to SW, max 86°
  Tuesday: 18:02, WSW to E, max 76° and 19:39, W, max 23°
  Wednesday: 18:51, W to NNE, max 84°
  Thursday: 18:03, W to E, max 86° and 19:39, W, max 24°
  Friday: 18:51, W to SE, max 84°
  Saturday: 18:03, W to E, max 87° and 19:40, W, max 25°
  Sunday: 18:52, W to SSE, max 57°

Week of 17th January

• Astronomical twilight ends at 18:30 UT at the start of the week and at 18:39 UT by the end of the week
• Try to spot Comet 19P/Borrelly in our southwestern evening sky. The comet is approaching perihelion on 1st February and lies just 1.2 AU away from Earth now. It is about magnitude +8, so binoculars or a telescope will be required. Look at an altitude of around 28° in Cetus, on the border with Pisces. A planetarium app will be useful to help locate the comet
• The Moon is Full on Monday – the Wolf Moon
• The Sun currently has eight active regions: AR 2924, 2925, 2926, 2927, 2929, 2930, 2931 & 2932. The sunspot number is 120
• There are multiple evening ISS passes this week as follows:
  Tuesday: 18:50, S, max 14°
  Wednesday: 18:03, SSE to SE, max 13° and 19:38, SW, max 13°
  Thursday: 18:51, SW to S, max 32°
  Friday: 18:04, SSW to ESE, max 27° and 19:40, WSW, max 18°
  Saturday: 17:18, S to E, max 19° and 18:53, WSW to SSW, max 58°
  Sunday: 18:07, SW to E, max 50° and 19:43, W, max 19°

Week of 10th January

• Astronomical twilight ends at 18:22 UT at the start of the week and at 18:29 UT by the end of the week
• Mercury (mag +0.1) reaches its highest altitude in the evening sky on Wednesday. Look at about 12° above the southwestern horizon just after sunset (16:23 UT) to observe the innermost inferior planet. It sits just 3° away from Saturn (0.7)
• The Moon is Waxing Gibbous all week
• The Sun currently has two active regions: AR 2924 & 2925. The sunspot number is 31
• There are no visible evening ISS passes this week

Week of 3rd January

• Astronomical twilight ends at 18:14 UT at the start of the week and at 18:20 UT by the end of the week
• The Quadrantid meteor shower peaks on Monday. This is one of the more spectacular annual showers, with a ZHR of around 120. The shower is active from 12 December to 12 January, as the Earth moves through debris deposited by asteroid 2003 EH1. The radiant of the shower is in the defunct constellation of Quadrans Muralis, an area of the sky now in the constellation of Bootes. The New Moon will make observing conditions ideal, if there is no cloud
• The Earth reaches perihelion on Tuesday morning, the point in its orbit that is closest to the Sun, when it will be just 0.9833 AU away. This will make the Sun appear at its largest in the sky, but given that the annual variance is only about 3%, it will be unnoticeable
• The Moon is First Quarter on Sunday
• The Sun currently has four active regions: AR 2916, 2918, 2922 & 2923. The sunspot number is 52
• There are no visible evening ISS passes this week

Week of 27th December

• Astronomical twilight ends at 18:08 UT at the start of the week and at 18:13 UT by the end of the week
• If the sky ever clears, it will be possible to view six planets in a line this week, starting with Mercury (mag -0.7) closest to the southwest horizon just after sunset at around 16:05 UT, next is Venus (-4.4), then Saturn (+0.7) and Jupiter (-2.2). As the sky reaches astronomical darkness, look for Neptune (+7.9) in the south and Uranus (+5.7) in the southeast
• For the early risers, add Mars (+1.5) to the planetary tally as it rises in the southeast at around 06:15 UT this week. It will be joined by the waning crescent Moon on Friday morning. To complete the solar system line up, spot the eighth and final planet by looking towards your feet!
• The Moon is Last Quarter on Monday and New on Sunday
• The Sun currently has seven active regions: AR 2908, 2912, 2915, 2916, 2917, 2918 & 2919. The sunspot number is 128
• There are no visible evening ISS passes this week

Week of 20th December

• Astronomical twilight ends at 18:04 UT at the start of the week and at 18:08 UT by the end of the week
• The Winter Solstice is on Tuesday, which will be the shortest day in the Northern Hemisphere and the first day of astronomical winter. The Sun will reach its lowest point in the sky at -23.5° declination. From this point on, it will be rising higher and higher and the days will lengthen as we head back towards summer – Happy Solstice!
• The Ursid meteor shower peaks through Tuesday night with its radiant in the constellation of Ursa Minor. It is not a particularly spectacular shower, with a ZHR of only around 10 meteors per hour, and the bright Moon is a hinderance, but you might spot a meteor caused by the debris deposited by comet 8P/Tuttle
• The planets Venus (mag -4.6), Saturn (+0.7) and Jupiter (-2.2) continue to adorn our evening sky in a line over the southwestern horizon around sunset
• The Moon is Waning Gibbous all week
• The Sun currently has six active regions: AR 2906, 2907, 2908, 2909, 2910 & 2911. The sunspot number is 117
• There are no visible evening ISS passes this week

Week of 13th December

• Astronomical twilight ends at 18:02 UT at the start of the week and at 18:04 UT by the end of the week
• The week starts with the ‘King’ of meteor showers, the Geminids. Its ZHR is upwards of 120, so can be spectacular. Unfortunately, the waxing gibbous Moon will drown out the fainter meteors this year. The shower is active from 7th to 17th December, with its peak on Monday night. Unusually for meteor showers, it is caused by debris deposited by an asteroid, Phaethon
• Venus (mag -4.7) reaches its highest altitude in our evening sky on Monday at about 13° above the southwestern horizon at 16:30 UT. Saturn (+0.7) and Jupiter (-2.2) complete a beautiful planetary twilight line up
• Comet C/2021 A1 Leonard, currently grazing our southwestern horizon at sunset, is about to sink lower, becoming visible only from more southerly latitudes by the middle of the week. It reaches perigee on Monday and perihelion on 2022-01-03
• The Moon is Full on Sunday
• Following an increasingly active year, the Sun currently has no active regions, though a new sunspot is emerging around the oncoming limb
• There are no visible evening ISS passes this week

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°

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

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°