December 2020 What’s Up!

Week of 28th December

  • Astronomical twilight ends at 18:09 UT at the beginning of the week and at 18:14 UT by the end of the week
  • The Quadrantid Meteor Shower peaks on Sunday, with a maximum ZHR (zenithal hourly rate) of 120 meteors. The radiant is in the old constellation of Quadrans Muralis, hence the name; however, Quadrans Muralis is no longer recognised, so the radiant appears in the modern day constellation of Bootes. The parent body responsible for the shower has been identified as asteroid 2003 EH1
  • The Earth passes through perihelion at 13:50 UT on Saturday, when it will be at its closest point to the Sun on its annual elliptical orbit. It will be 0.98 AU from the Sun or 147 million km. This is in contrast to its distance of 152 million km when at aphelion. Consequently, the Sun will appear about 3% larger, though it will be extremely difficult to notice this difference!
  • The Moon is Full on Wednesday
  • The Sun currently has two active regions, AR 2794 & AR 2795 – the sunspot number is 31
  • There are no visible ISS evening passes this week

Week of 21st December

  • Astronomical twilight ends at 18:05 UT at the beginning of the week and at 18:08 UT by the end of the week
  • The Great Conjunction is on Monday, when Jupiter (-2.0) and Saturn (+0.6), will be separated by just 6 arcminutes. This is the closest that they have appeared since 1623. Due to their orbital mechanics, Jupiter ‘undertakes’ Saturn roughly every 20 years, so conjunctions are not particularly rare. However, the inclination of the planets’ orbits with respect to the Earth means that they are not often this close together. Combine this with the angular distance of the planets from the Sun, meaning that some conjunctions are too close to the Sun to be observed and you will see that this is a rare event. The next Great Conjunction will be in 2080, so if there is a clear sky, take the opportunity to enjoy this rare view of the two gas giants in the same field of view of your binoculars or telescope. You can also look in the days before and after the 21st as the two planets pass eachother
  • Monday is also the Winter Solstice, marking the lowest point the Sun appears in the sky at a declination of -23.5°. It is the shortest day of the year and the start of winter in the Northern Hemisphere. Christmas borrows its date from this pagan festival. Nowadays Christmas is a few days after the Winter Solstice due to the Leap Year only being introduced in the 16th Century. Before the introduction of the extra leap days, the calendar and the astronomical event slowly drifted apart over the years
  • The Ursid Meteor shower peaks on Tuesday. It is not a particularly active shower, with a peak rate of around 10 meteors per hour. The shower’s radiant is in Ursa Minor and the meteors are caused by the Earth passing through the stream of debris created by comet 8P/Tuttle
  • The Moon is First Quarter on Monday
  • After a recent active period, the Sun is now quiet with no active regions – the current stretch is 1 day
  • There are no visible ISS evening passes this week

Week of 14th December

  • Astronomical twilight ends at 18:02 UT at the beginning of the week and at 18:04 UT by the end of the week
  • Watch Jupiter (-2.0) and Saturn (0.6) in the southwestern evening sky just after sunset as they approach eachother through this week, culminating in The Great Conjunction on Monday 21st December. They start the week 47 arcminutes apart and by Sunday, will have just 9 arcminutes of separation. If there is a clear sky, take the opportunity to enjoy this rare view of the two gas giants in the same field of view of your binoculars or telescope
  • There is a total solar eclipse on Monday. Don’t get too excited though, it will not be visible from Marlborough! Observers in Chile and Argentina will witness this spectacular solar system syzygy between 13:34 and 18:53 UT, with totality expected to last for 2 minutes and 10 seconds at the point of greatest eclipse. Check on line for a live feed of the eclipse
  • The Moon is New on Monday
  • The Sun currently has two active regions: AR 2790 and AR 2792, with a combined sunspot number of 24
  • There are no visible ISS passes this week

Week of 7th December

  • Astronomical twilight ends at 18:02 UT at the beginning of the week and at 18:02 UT by the end of the week
  • The Geminid meteor shower peaks on Sunday night. As the Earth passes through debris deposited in space by asteroid 3200 Phaethon, we can enjoy one of the finest cosmic fireworks shows of the year! The Geminids can produce up to 110-120 meteors per hour at its peak, which occurs this year at about 01:00 UT on Monday 14th. The Moon is New on the 14th, so observing conditions will be perfectly dark. All that is needed is no cloud. Even that is not a problem this year as the new Blackett Observatory Radio Meteor Detection System is now live and will be listening out for meteor ‘pings’, whatever the weather
  • The Moon is Last Quarter on Tuesday
  • The Sun currently has three active regions: AR 2785, AR 2786 and AR 2790, with a combined sunspot number of 42
  • The ISS makes multiple evening passes as follows:
    Monday: 18:07, W to S, max 18Â
    Tuesday: 17:19, W to SSE, max 25Â
    Wednesday: 16:31, W to SE, max 34Â
    Thursday: 17:22, WSW to SSW, max 12Â
    Friday: 16:33, W to S, max 18Â

November 2020 What’s Up!

Week of 30th November

  • Astronomical twilight ends at 18:03 UT at the beginning of the week and at 18:02 UT by the end of the week
  • Mars continues to be the highlight of our evening sky, shining at mag -1.1. Binoculars or a small telescope are sufficient to show dark patches on the planet’s surface
  • The Moon is Full on Monday – the Cold Moon. Having passed through apogee last Friday, this full Moon will be a ‘micromoon’, appearing slightly smaller and dimmer than usual
  • The Sun is very active right now, moreso than it has been for many months. It has four active regions: AR 2783, AR 2785, AR 2786 and AR 2787, with a combined sunspot number of 67. Look on the GONG/NSO website for impressive H Alpha images: Click here for GONG
  • The ISS makes multiple evening passes as follows:
    Monday: 17:12, W to E, max 87° & 18:49, W, max 31°
    Tuesday: 18:02, W to ESE, max 87°
    Wednesday: 17:14, W to E, max 86° & 18:51, W to WSW, max 30°
    Thursday: 18:03, W to SE, max 61°
    Friday: 17:16, W to ESE, max 76° & 18:53, W to SW, max 23°
    Saturday: 18:05, W to SSE, max 34°
    Sunday: 17:17, W to SE, max 46° and 18:55, WSW to SSW, max 12°

Week of 23rd November

  • Astronomical twilight ends at 18:07 UT at the beginning of the week and at 18:04 UT by the end of the week
  • On Wednesday night the Moon (-11) and Mars (-1.3) traverse the sky together at only 5° separation
  • The Moon is Waxing Gibbous and will be Full early next week. It reaches apogee on Friday, when it will be at its most distant orbital point from Earth at about 403,000 km away. It will appear slightly smaller in the sky than usual, subtending only 29.4 arcminutes across the sky, compared to its average size of 31.1 arcmin
  • The Sun has two active regions, AR 2783 and AR 2784, with a combined sunspot number of 23. This continues the sustained increase in solar activity as Solar Cycle 25 intensifies
  • The ISS makes multiple evening passes as follows:
    Monday: 17:55, SSW to SE, max 31° & 19:31, WSW, max 12°
    Tuesday: 17:08, SSW to E, max 22° & 18:44, WSW, max 36°
    Wednesday: 17:56, SSW to ESE, max 56° & 19:33, W, max 12°
    Thursday: 17:09, SW to E, max 42° & 18:46, W, max 37°
    Friday: 17:58, WSW to SE, max 84° & 19:35, W, max 11°
    Saturday: 17:11, WSW to E, max 71° & 18:47, W, max 34°
    Sunday: 18:00, W to ENE, max 84° and 19:37, W, max 10°

Week of 16th November

  • Astronomical twilight ends at 18:13 UT at the beginning of the week and at 18:08 UT by the end of the week
  • The Leonid meteor shower peaks on Tuesday night. The radiant is in the head of Leo. The shower produces a maxiumum of around 15 meteors per hour and is created by the Earth moving through debris left behind by Comet 55P/Tempel-Tuttle, which was discovered in 1865, five years after the Cooke 10-inch was made
  • Mars continues to dominate the evening sky, shining at mag -1.5 and culminating at 21:07 UT
  • The Moon will be First Quarter on Sunday. It will make a close approach to Jupiter (-2.1) and Saturn (0.6) as it sets on Thursday evening
  • The Sun has one departing active region, AR 2781
  • The ISS returns to our evening skies this week with passes as follows:
    Friday: 18:41, SSW to S, max 13°
    Saturday: 17:55, S to SE, max 16°
    Sunday: 17:09, SSE to ESE, max 11° and 18:43, SW to SSW, max 26°

Week of 9th November

  • Astronomical twilight ends at 18:21 UT at the beginning of the week and at 18:14 UT by the end of the week
  • Mercury (-0.6) reaches greatest elongation west on Tuesday and will be at its highest point in the morning sky, reaching an altitude of 15°. It is separated from the Sun by about 19°, take care if trying to observe Mercury. Venus is nearby shining at -4.0. Early risers will be treated to a fine view when the waning crescent Moon joins the scene on Thursday morning, making a beautiful trio of solar system objects
  • The Moon will be New on Sunday
  • The Sun has two active regions AR 2780 and AR 2781, with a combined sunspot number of 37. AR 2781 is the largest active region of the new solar cycle and is facing Earth, which could pose a geoeffective risk if it produces significant eruptions
  • There are no visible ISS evening passes this week

Week of 2nd November

  • Astronomical twilight ends at 18:31 UT at the beginning of the week and at 18:22 UT by the end of the week
  • The planets continue to make an impressive line of observing targets across the night sky, from west to east: Jupiter (-2.1), Saturn (0.6), Neptune (7.8), Mars (-2.0), Uranus (5.7) and for the early risers, Venus (-4.0) and Mercury (0.1)
  • Whilst not the most productive of meteor showers with only around 5 to 10 meteors per hour, the Taurids can be impressive. The shower peaks on Wednesday night. The Taurids are unusual in that they are generated by two separate streams of material, the first left behind by Asteroid 2004 TG10 and the second deposited by Comet 2P Enke
  • The Moon will be Last Quarter on Sunday
  • The Sun has two departing active regions AR 2778 and AR 2779, with a combined sunspot number of 26
  • There are no visible ISS evening passes this week

October 2020 What’s Up!

Week of 26th October

  • Astronomical twilight ends at 18:42 UT at the beginning of the week and at 18:33 UT by the end of the week
  • Mars continues its journey westwards across our night sky, shining brightly at mag -2.3. Use binoculars or a telescope to observe surface features on the Red Planet. On Thursday it will be in conjunction with the Moon, separated by only 8°
  • Uranus reaches opposition on Saturday. It will be 18.79 AU from Earth, about 2.8 billion km away. At mag +5.7 and 3.8 arcsec, it is best observed through a telescope. Due to the proximity of the Full Moon on Saturday, it will be easier to spot the planet a day or two before or after opposition
  • The Moon will be Full on Saturday, the Hunter’s Moon. This is the second Full Moon of the month, making it known as a Blue Moon, though it won’t appear tinged blue! This use of the term ‘Blue Moon’ is a twentieth century custom that started in 1946. Historically the term was used to name a fourth Full Moon of a season, where normally only three Full Moons appear per season and have traditional names
  • The Sun currently has one active region AR 2776, which contains 11 sunspots
  • There are no visible ISS evening passes this week

Week of 19th October

  • Astronomical twilight ends at 19:56 BST at the beginning of the week and at 18:44 GMT by the end of the week
  • British Summer Time ends on Sunday, when the clocks go back one hour at 02:00 BST to become 01:00 GMT
  • Mars continues to be the highlight of our evening sky, shining brightly at mag -2.5. It rises at 18:00 BST and reaches its highest elevation of 43° around midnight
  • Jupiter (-2.2) and Saturn (0.5) are still visible, but have set by about 22:30 BST
  • The Orionid meteor shower peaks on Wednesday. It can produce around 15 to 20 meteors an hour. The parent body that creates this meteor shower has been identified as comet 1P/Halley
  • The Moon will be First Quarter on Friday. On Thursday and Friday evenings it will make a close approach to Jupiter and Saturn
  • The Sun currently has one active region AR 2776, which contains around 15 sunspots
  • There are no visible ISS evening passes this week

Week of 12th October

  • Astronomical twilight ends at 20:10 BST at the beginning of the week and at 19:58 BST by the end of the week
  • At 00:18 BST on Wednesday, Mars will be at opposition, situated directly opposite the Sun. This is the best time this decade to observe Mars as it will be at its largest and brightest in our night sky. It will be about 0.42 AU away, shining at a magnitude of -2.6 and its disc will measure 22.3 arcseconds in diameter. It is at its highest point in the sky at around 01:00 BST, when it will be at an altitude of about 43°. Get out there and observe Mars, ideally through binoculars or a telescope; can you see any dark surface feature details?
  • The Moon will be New on Friday
  • The Sun currently has two sunspots, active regions AR 2774 and AR 2775. Their polarity and high southerly latitude identify them as members of the new Solar Cycle 25
  • There are no visible ISS evening passes this week

Week of 5th October

  • Astronomical twilight ends at 20:26 BST at the beginning of the week and at 20:12 BST by the end of the week
  • Mars reaches perigee on Tuesday, when it will be at the closest point to Earth in its orbit, around 62 million km. This makes Mars appear largest and brightest in our sky, at magnitude -2.6 with an apparent size of 22.6 arc seconds. It is moving ever closer to opposition, which occurs on 14th October
  • The Moon will be Last Quarter on Saturday
  • The Sun currently has no visible sunspots. This spotless stretch is 8 days
  • There are no visible ISS evening passes this week

September 2020 What’s Up!

Week of 28th September

  • Astronomical twilight ends at 20:42 BST at the beginning of the week and at 20:28 BST by the end of the week
  • The planets continue to impress in our evening sky. Mars (-2.5) is climbing ever higher, rising at around 19:30 BST this week. Jupiter (-2.4) and Saturn (0.5) are in the West, setting at around midnight
  • The Moon will be Full on Thursday 1st October – the Harvest Moon. Occuring so early in the month allows a second Full Moon to fall in October, the 31st will see a ‘Blue’ Moon
  • The Sun currently has no visible sunspots. Active Region 2773 lasted for three days during last week, but has now settled down
  • The ISS makes multiple evening passes this week as follows:
    Monday: 20:48, W to S, max 73°
    Tuesday: 20:01, W to ESE, max 85° & 21:38, W, max 19°
    Wednesday: 19:14, W to E, max 87° & 20:51, W to SSW, max 43°
    Thursday: 20:03, W to SE, max 57° & 21:41, W to WSW, max 12°
    Friday: 19:16, W to ESE, max 72° & 20:53, W to SSW, max 23°
    Saturday: 20:06, W to SSE, max 32°
    Sunday: 19:18, W to SE, max 43° & 20:57, WSW to SSW, max 11°

Week of 21st September

  • Astronomical twilight ends at 21:00 BST at the beginning of the week and at 20:45 BST by the end of the week
  • The September Equinox is on Tuesday and marks the start of autumn for the Northern Hemisphere. The Sun will cross the celestial equator at 14:15 BST on the 22nd and continue its journey appearing ever lower in the sky as we head towards winter. Day and night will be equal at 12 hours each and the Sun will rise due East and set due West, one of only two days in the year when this occurs. The nights are becoming longer, which is only a good thing for astronomers!
  • Mars is a beautiful evening object, shining at mag -2.3 with a distinct orange-red colour
  • Jupiter and Saturn continue to impress and will be joined by the Waxing Gibbous Moon on Friday
  • The Moon will be First Quarter on Thursday
  • The Sun is currently blank with no visible sunspots – this spotless stretch is now at 30 days
  • The ISS makes multiple evening passes this week as follows:
    Monday: 19:52, SW to E, max 32° & 21:28, WSW to WSW, max 46°
    Tuesday: 20:41, WSW to E, max 73° & 22:18, W, max 14°
    Wednesday: 19:54, WSW to E, max 58° & 21:30, W, max 43°
    Thursday: 20:43, W to E, max 87° & 22:20, W, max 12°
    Friday: 19:56, WSW to E, max 85° & 21:32, W, max 36°
    Saturday: 20:45, W to E, max 86°
    Sunday: 19:58, W to E, max 84° & 21:34, W, max 28°

Week of 14th September

  • Astronomical twilight ends at 21:19 BST at the beginning of the week and at 21:03 BST by the end of the week
  • Mars is appearing ever higher in our evening sky. It is shining a fabulous orange-red colour and is currently at magnitude -2.1; this will brighten to -2.6 when at opposition in October
  • There is only a month or two left to observe Jupiter and Saturn. They are both in our western sky now and have set by about 01:00 BST
  • The Moon will be New on Thursday
  • The Sun is currently blank with no visible sunspots – this spotless stretch is now at 23 days; the deep solar minimum continues
  • The ISS returns to our evening skies with passes this week as follows:
    Thursday: 21:25, SW to SSW, max 14°
    Friday: 20:38, SSW to SSE, max 23°
    Saturday: 19:51, S to ESE, max 16° and 21:26, WSW to SW, max 33°
    Sunday: 20:39, SW to ESE, max 43° and 22:15, W, max 14°

Week of 7th September

  • Astronomical twilight ends at 21:38 BST at the beginning of the week and at 21:22 BST by the end of the week
  • Jupter (-2.5) and Saturn (+0.3) continue their journey westwards across our evening sky and make fabulous observing targets
  • On Tuesday, Venus reaches its highest point in the morning sky when it will be at about 35° altitude at sunrise, shining brightly at mag -4.2
  • Neptune reaches opposition on Friday and will be well placed at about 24° altitude in the southeast at 22:30 BST. Being only around mag +8, binoculars or a telescope will be required to observe the outermost planet in the solar system
  • Mars, shining at mag -2 in the East, is becoming an increasingly evident player on the stage of our evening sky as it moves towards opposition in October
  • The Moon will be Last Quarter on Thursday
  • The Sun is currently blank with no visible sunspots – this spotless stretch is now at 16 days
  • There are no evening ISS passes this week

August 2020 What’s Up

Week of 31st August

  • Astronomical twilight ends at 21:59 BST at the beginning of the week and at 21:41 BST by the end of the week
  • The planets offer the best observing targets this week with Jupiter at mag -2.5 transiting at around 21:30 BST, Saturn at mag +0.3, transiting at around 22:00 BST and Mars at mag -1.9 that transits at around 04:00 BST
  • The Moon will be Full (Harvest Moon) on Wednesday
  • The Sun is currently blank with no visible sunspots – this spotless stretch is now at 9 days
  • There are no evening ISS passes this week

Week of 24th August

  • Astronomical twilight ends at 22:20 BST at the beginning of the week and at 22:02 BST by the end of the week
  • Jupiter (-2.6) and Saturn (+0.3) continue to dominate the night sky in the South. They transit at around 22:00 and 22:35 BST respectively, so are well placed for observation in the evening sky
  • Mars is the rising centrepiece as it moves towards opposition in mid October. It will be at perigee in early October, making this apparition particularly favourable for observation. Mars is currently shining at mag -1.7 and brightening. It rises at around 22:00 BST and transits at 04:30 BST
  • The Moon will be First Quarter on Tuesday
  • The Sun is currently blank with no visible sunspots
  • There are no evening ISS passes this week

Week of 17th August

  • Astronomical twilight ends at 22:43 BST at the beginning of the week and at 22:24 BST by the end of the week
  • Seven Planet Challenge: It will be possible to see seven of the eight solar system planets this week. Start with Jupiter (-2.6) and Saturn (+0.2) in the southern evening sky. Next is Neptune (+7.8), which will be in the southeast around midnight. Mars (-1.5) will be at about 24° altitude in the East at 01:00 BST. Uranus (+5.8) is approx 16° further East. Venus (-4.3) rises at 02:08 BST. Finally, look to your feet for the seventh planet! Unfortunately, the full set is not possible as Mercury is hiding in the glare of the Sun
  • The Moon will be New on Wednesday
  • The Sun is currently blank with no visible sunspots
  • There are no evening ISS passes this week

Week of 10th August

  • Astronomical twilight ends at 23:07 BST at the beginning of the week and at 22:46 BST by the end of the week
  • The Perseid meteor shower peaks on Wednesday afternoon. Watch out on both Tuesday night (11th) and Wednesday night (12th) for this wonderful annual display of shooting stars as the Earth crashes through debris left behind by comet 109P/Swift-Tuttle. The Last Quarter Moon makes for good observing conditions and the shower can generate over 100 meteors per hour. Unfortunately, the current weather forecast is for thunderstorms, so grab your chance between clouds to spot a few Perseids
  • Jupiter and Saturn continue to shine brightly in our southern evening sky. On Tuesday, the shadow of the Gallilean moon Callisto will transit Jupiter’s disc, starting at 19:43 BST and moving off the disc at 23:55 BST
  • Venus reaches Greatest Elongation West on Wednesday, visible in the eastern morning sky at an altitude of about 32° just before sunrise, shining at mag -4.3, making it the third brightest object in the sky after the Sun and the Moon
  • The Moon will be Last Quarter on Tuesday
  • The Sun has one active region, AR 2770, which belongs to the new Solar Cycle 25
  • There are no visible evening ISS passes this week

Week of 3rd August

  • Astronomical twilight ends at 23:29 BST at the beginning of the week and at 23:06 BST by the end of the week
  • The Perseid meteor shower (Tears of St Lawrence) peaks in the afternoon of Wednesday 12th August. Usually one of the best showeres in the year, this year is favourable with a waning Moon and 80+ meteors an hour are predicted at peak. There is usually a good build up to the peak, so it is worth looking out for early shooting stars later this week and next week-end. Government guidlines and weather permitting a small gathering at the Dome may be permitted on 12th. Watch the website for updates.
  • Jupiter and Saturn continue to shine brightly in our southern evening sky. On Monday to the West of the Full Moon.
  • The Moon will be at Full (Sturgeon or Barley Moon) on Monday
  • The Sun has two active regions, AR 2767 and a fast growing spot 2769 on the NE limb, both belonging to the new Solar Cycle 25
  • There are no visible evening ISS passes this week.

July 2020 What’s Up!

Week of 27th July

  • Astronomical twilight ends at 00:08 BST at the beginning of the week and at 23:37 BST by the end of the week
  • Goodbye Comet NEOWISE (C/2020 F3)! The comet passed perigee on the 23rd and is now travelling away from both the Earth and Sun. It is fading and has dropped to about mag +3. This, along with the waxing Moon, will make it increasingly difficult to spot. This comet is not due to return to our skies for about 6,800 years. For a last look, find the comet after sunset in the northwest below the Plough
  • The Southern Delta Aquariid meteor shower peaks on Wednesday night. However, with only about 25 meteors per hour at its peak, which will reduce to around just 9 visible per hour due to the bright Moon, this is unlikely to be a particularly spectacular shower. The radiant is in Aquarius and the parent body responsible for the shower is thought to be comet P/2008 Y12 (SOHO)
  • Jupiter (-2.7) and Saturn (+0.1) continue to shine brightly in our southern evening sky. The pair are joined by a 97% waxing Moon on Saturday, when Jupiter will lie just 2° above the Moon
  • Mercury reaches its highest point in the morning sky on Monday. At sunrise, 05:24 BST, it will be at an altitude of 12° in the East. Take great care to avoid the Sun if trying to observe this event
  • The Moon will be at First Quarter on Monday
  • The Sun has one active region, AR 2767, in a high southerly latitude belonging to new Solar Cycle 25
  • The ISS makes visible evening passes this week as follows:
    Monday – 21:42, W to ESE, max 73° & 23:19, W to SSW, max 23°
    Tuesday – 22:31, W to SSE, max 32°
    Wednesday – 21:43, W to SE, max 44° & 23:21, WSW to SW, max 11°
    Thursday – 22:32, W to S, max 17°
    Friday – 21:44, W to SSE, max 24°
    Sunday – 21:46, WSW to SSW, max 12°

Week of 20th July

  • This week sees the return of astronomical darkness. On Monday night, starting at 00:51 BST, we will enjoy 54 minutes of ‘proper’ darkness. By Sunday, astronomical twilight will end at 00:14 BST, with astronomical darkness lasting for two hours
  • Comet NEOWISE (C/2020 F3) continues to put on a fabulous display, though it is now starting to dim as it travels away from the Sun. It is best viewed in the evening sky, at 23:00 BST it is at an altitude of about 20° above the northwestern horizon. At the start of the week it is sitting around 15° below the Plough, by the front paw of the Great Bear, by the end of the week it will have moved West to sit behind the Bear’s back paw. Whilst it is still visible with the naked eye, the best views are gained with binoculars
  • Jupiter and Saturn make excellent evening targets in the southeastern sky this week. They are low to the horizon at an altitude of about 12°. Jupiter is mag -2.7 and Saturn is mag +0.1. Saturn reaches opposition on Monday, meaning it lies opposite the Sun from Earth and is best placed for the largest and brightest views. Look out for the transit of Jupiter’s moon Callisto on Saturday night, it moves across the gas giant’s disk from 22:55 BST until 03:00 BST on Sunday morning
  • Mercury is at Greatest Elongation West on Wednesday and will be visible at about 05:00 BST, just before sunrise, in the northeast at an altitude of about 9° shining at around mag +0.5. Venus is also a morning object, rising at around 02:30 BST and shining as the bright ‘morning star’ at mag -4.4
  • The Moon is New on Monday
  • The Sun has no active regions, with the current spotless stretch at 8 days
  • The ISS makes visible evening passes as follows:
    Monday – 22:27, W to E, max 87°
    Tuesday – 23:16, W to E, max 87°
    Wednesday – 22:28, W to E, max 84°
    Thursday – 23:17, W to ESE, max 72°
    Friday – 22:29, W to ESE, max 85°
    Saturday – 23:17, W to SSE, max 44°
    Sunday – 22:29, W to SE, max 58°

Week of 13th July

  • Astronomical twilight does not end until 21st July
  • Comet NEOWISE (C/2020 F3) is the finest comet to appear in our skies for many years. It is now circumpolar and is visible from sunset to sunrise. However, it is very low to the northern horizon, so you need to choose your observing location accordingly. Through the week it increasingly becomes an evening object. It is at 10° altitude and 338° azimuth at 23:00 BST on Monday evening, moving to 8° alt, 10° az by 02:00 BST that night. By Friday, it is at 16° alt, 330° az, at 23:00 BST and 9° alt, 359° az, at 02:00 BST on Saturday morning. This is a must see object, let’s hope for clear skies!
  • The planets make an impressive line up across the southern sky this week. Jupiter (mag -2.8) reaches opposition on Tuesday, it is also at perigee, making this the best time to observe Jupiter at its largest and brightest in our sky. It is visible along with Saturn (mag 0.1) at an altitude of around 14° above the southeastern horizon throughout the evening. For the night owls and early risers, Mars appears above the eastern horizon after midnight, followed by Venus, which rises in the northeast at about 02:45 BST. The waning crescent Moon rises within 3° of Venus on Friday morning and will make an impressive sight
  • The Moon is waning and starts the week at Last Quarter on Monday
  • The Sun currently has no active regions
  • The ISS is visible in our skies again with evening passes as follows:
    Monday – 23:13, SSW to E, max 25°
    Tuesday – 22:26, S to E, max 18°
    Wednesday – 23:13, 23:13, SW to E, max 47°
    Thursday – 22:26, SW to E, max 34°
    Friday – 23:14, WSW to E, max 76°
    Saturday – 22:26, WSW to E, max 61°
    Sunday – 23:15, W to E, max 86°

Week of 6th July

  • Astronomical twilight does not end until 21st July
  • The Gas Giants, Jupiter and Saturn, are visible in the southeastern evening sky, with Jupiter rising at 21:41 BST and Saturn following close behind at 22:00 BST. Jupiter appears at about mag -3, while Saturn is some 16 times dimmer at mag 0. Watch as the Full Moon forms a right angle triangle with the two planets on Sunday night into Monday morning. Jupiter and Saturn both reach opposition later this month
  • Mars is starting to appear in our night sky, rising at around 00:30 BST. The best views will be later in the year as it reaches opposition in October
  • Venus continues to grace our morning skies, rising at around 03:00 BST and shining at mag -4.5 towards the northeast in the Hyades
  • The Moon is Waning Gibbous all week
  • The Sun has one small active region near its equator. The low latitude and magnetic polarity identify it as a member of the old Cycle 24, which still has a bit of life in it yet
  • There are no ISS evening passes visible this week

June 2020 What’s Up!

Week of 29th June

  • Astronomical twilight does not end until 21st July
  • The Earth reaches aphelion on Saturday, the furthest point from the Sun in its annual orbit. It will be at a distance of 1.02 AU. Summer in the Northern hemisphere has nothing to do with the Earth – Sun distance, it is due to the tilt of the Earth’s axis being towards the Sun at this time of year
  • Venus is now a morning object, rising at around 03:30 BST and shining at about mag -4 in the East
  • The Moon is waxing and will be Full on Sunday
  • The Sun has one active region, AR 2766, in the southern hemisphere approaching the off going limb. This is the tenth Solar Cycle 25 sunspot this year, which indicates that the new cycle is gaining strength
  • There are no ISS evening passes visible this week

Week of 22nd June

  • Astronomical twilight does not end until 21st July
  • Jupiter and Saturn are now late evening risers. On Thursday there is a shadow transit of Jupiter’s largest moon, Ganymede. The transit commences at 23:35 BST and continues until 02:50 BST. Look about 8° above the southeastern horizon with binoculars to find Jupiter and observe this event
  • The Moon is waxing and will be First Quarter on Sunday
  • The Sun is quiet again and has no active regions
  • There are no ISS evening passes visible this week

Week of 15th June

  • Astronomical twilight does not end until 21st July
  • A lunar occultation of Venus occurs on Friday morning. Venus will be hidden from view at around 08:37 BST as the Moon passes between it and the Earth. It will re-emerge just over an hour later at about 09:42 BST. As this all happens in daylight with a thin waning crescent Moon, it will be quite tricky to spot the reappearance of Venus, but the start of the occultation should be easier to observe
  • The Summer Solstice is on Saturday. At 22:27 BST the Sun will be at its highest declination of around +23.5°, making 20th June the longest day this year in the Northern Hemisphere. This marks the astronomical start of summer. This day also sees the Sun setting at its most northerly point on the horizon, about 41° north of due West. The Sun used to be in the constellation of Cancer on the Summer Solstice, creating the Tropic of Cancer, the most northerly line of latitude on Earth which sees the Sun directly overhead. However, nowadays, due to precession (the wobble of the Earth on its axis over a 26,000 year period) the Sun is actually in Taurus
  • There is an annular solar eclipse on Sunday morning between 04:47 and 10:34 BST, but it will not be visible from the UK. Only observers in Africa and Asia will be direct witness to this spectacular heavenly event
  • The Moon is waning and will be New on Sunday
  • The Sun has one active region, AR2765, at a high southerly latitude
  • There are no ISS evening passes visible this week

Week of 8th June

  • Astronomical twilight does not end until 21st July
  • Keep an eye out for noctilucent clouds towards the northern horizon in the hour after sunset and before sunrise
  • Jupiter, Saturn and Mars are currently rising at around midnight to 1 am. They will become evening objects in about a month
  • The Moon is waning and will be Last Quarter on Saturday
  • The Sun has one active region, AR2765, at a high southerly latitude
  • There are no ISS evening passes visible this week

Week of 1st June

  • Astronomical twilight does not end until 21st July
  • Mercury reaches greatest eastern elongation on Thursday. Look to the northwest in the hour after sunset to spot Mercury at around 10° altitude
  • Reports suggest that Comet C/2020 F8 (SWAN) has dimmed significantly and is possibly disintegrating. Another comet that has failed to live up to the stories
  • Noctilucent cloud season has started. Look to the North in the hour after sunset to spot these opalescent clouds. They reside in the mesosphere some 80 km above the ground and are formed by water vapour crystallising around particles in the high atmosphere. They reflect the sunlight still able to reach those altitudes as the Sun has not sunk far below the horizon
  • The Moon is waxing and will be Full on Friday
  • The Sun has no active regions, with the current spotless stretch at 29 days
  • The ISS makes just one evening pass this week:
    Monday: 22:12, WSW to SSW, max 13°

May 2020 What’s Up!

Week of 25th May

  • Astronomical twilight does not end until 21st July as the Sun does not sink lower than 18° below the horizon
  • Mercury reaches its highest point in the evening sky on Sunday. Look to the northwest in the hour after sunset to see Mercury climb ever higher this week
  • Comet C/2020 F8 (SWAN) reaches perihelion on Friday. Look to 18° altitude above the northwestern horizon at around 10pm BST. It is about mag +6, on the border of naked eye visibility, but given its low altitude and the lack of darkness, binoculars will be required
  • On Wednesday evening at 9.32pm BST you should be able to watch the NASA/SpaceX Demo-2 live launch online. The first launch from US soil to the ISS since 2011
  • Binocular Deep Sky Target of the Week: M13, The Great Hercules Cluster. This globular cluster is the brightest in the Northern Hemisphere sky and is easily visible in binoculars at mag +5.8. Look on the western side of the Keystone asterism in the constellation of Hercules. It lies about 25,000 light years away and contains some 300,000 stars
  • The Moon is waxing and will be First Quarter on Saturday
  • The Sun has no active regions, with the current spotless stretch at 22 days
  • The ISS makes the following evening passes this week:
    Monday: 22:55, W to ESE, max 62°
    Tuesday: 22:07, W to ESE, max 76° and 23:44, W to SSW, max 25°
    Wednesday: 22:57, W to SSE, max 35°
    Thursday: 22:09, W to SE, max 47° and 23:46, WSW to SW, max 13°
    Friday: 22:58, W to S, max 18°
    Saturday: 22:10, W to SSE, max 26°

Week of 18th May

  • Astronomical twilight ends at 00:16 BST at the start of the week. From Saturday, Astronomical Twilight does not end until 21st July as the Sun never sinks lower than 18° below the horizon
  • Mercury starts to climb into the western evening sky. On Thursday and Friday it is in conjunction with Venus, separated by less than 2° (Be careful of the setting Sun if you attempt to spot Mercury with binoculars)
  • Comet C/2020 F8 (SWAN) is now low in the northern horizon and is at around mag +6
  • The Moon is waning and will be New on Friday
  • The Sun has no active regions, with the current spotless stretch at 14 days
  • The ISS makes multiple bright evening passes this week as follows:
    Monday: 22:03, SW to E, max 42° and 23:40, W to E, max 87°
    Tuesday: 22:52, WSW to E, max 84°
    Wednesday: 00:29, W to ESE, max 87°, 22:04, WSW to E, max 71° and 23:41, W to E, max 86°
    Thursday: 22:53, W to E, max 84°
    Friday: 00:30, W to S, max 61°, 22:05, W to E, max 88° and 23:42, W to ESE, max 76°
    Saturday: 22:54, W to E, max 88°
    Sunday: 00:31, W to SW, max 31°, 22:06, W to E, max 86° and 23:43, W to SSE, max 47°

Week of 11th May

  • Astronomical twilight ends at 23:39 BST at the start of the week and 00:09 BST at the end
  • Venus is appearing to change rapidly as it moves towards inferior conjunction; it starts the week as a 15% crescent and finishes at 10%. It is increasing in apparent size and will appear about 50 arcseconds by the end of the week. For comparison, at the end of 2019 it appeared only about 12 arcseconds in size
  • Comet C/2017 T2 (PANSTARRS) is expected to be at its brightest on Wednesday as it moves through Camelopardalis towards Ursa Major. It is a binocular target at around mag +8
  • Comet C/2020 F8 (SWAN) will become visible low to the northeastern horizon in our morning sky from the middle of the week. It has been exciting observers in the Southern Hemisphere as it is on the border of naked eye visibility at mag +6 and has a very elongated tail. It will be fascinating to watch how this comet develops over the coming weeks
  • The Moon is waning and will be Last Quarter on Thursday
  • The Sun has no active regions, with the current spotless stretch at 8 days
  • The ISS returns to our evening sky this week with passes as follows:
    Friday: 22:50, SW to E, max 31°
    Saturday: 22:03, SSW to E, max 23° and 23:38, WSW to E, max 72°
    Sunday: 22:51, WSW to E, max 57°

Week of 4th May

  • Astronomical twilight ends at 23:12 BST at the start of the week and 23:35 BST at the end
  • While Comet C/2019 Y4 (ATLAS) may have disappointed by breaking up, comets C/2017 T2 (PANSTARRS) and C/2020 F8 (SWAN) may give observers something to enjoy. PANSTARRS reaches perihelion on Tuesday and is well placed in Camelopardalis; however, at mag +8, binoculars or a telescope will be needed. Comet SWAN is not visible in the Northern Hemisphere yet, but should appear in our skies towards the end of May
  • Venus will appear in its crescent phase this week, shining brightly at mag -4.5 in the western evening sky
  • The Eta Aquarid meteor shower peaks on Wednesday, though the Full Moon will drown out the majority of meteors. The shower is a result of the Earth passing through the stream of debris deposited by Halley’s Comet
  • The Moon will be Full on Thursday. This will be the ‘Flower Moon’, the fourth and last supermoon of the year
  • The Sun has no active regions, with the current spotless stretch at 2 days
  • There are no visible evening ISS passes this week

April 2020 What’s Up!

Week of 27th April

  • Astronomical twilight ends at 22:48 BST at the start of the week and 23:08 BST at the end
  • Venus continues its orbit around the Sun, now moving closer to Earth, reaching its 25% illuminated phase on Friday. It appears larger and brighter in the evening sky, shining at mag -4.5. It will be at inferior conjunction on 3rd June, when it passes between Earth and the Sun. Unfortunately, the three will not be in syzygy this time; the next transit of Venus is not until 2117
  • The Moon will be First Quarter on Thursday, at this phase for the second time this month
  • There is one small sunspot on the Sun, AR 2760; it is close to the equator and part of Solar Cycle 24
  • There are no visible evening ISS passes this week

Week of 20th April

  • Astronomical twilight ends at 22:27 BST at the start of the week and 22:45 BST at the end
  • The peak of the Lyrid meteor shower is on the 22nd April, with meteors possible all week. It generates only around 17 to 18 meteors per hour, so is not as spectacular as the Geminids or Perseids with their maximum ZHRs of 80 to 100 meteors, but given the lack of moonlight, those that appear should be easy to spot. As the name suggests, the radiant is in the constellation of Lyra. The shower occurs as the Earth passes through debris left behind by comet C/1861 G1 (Thatcher)
  • The Moon will be New on Thursday
  • There are currently no active regions on the Sun, with the spotless stretch now at 14 days
  • There are no visible evening ISS passes this week

Week of 13th April

  • Astronomical twilight ends at 22:09 BST at the start of the week and 22:25 BST at the end
  • Unfortunately it appears that Comet C/2019 Y4 (ATLAS) is not going to give us the display that was anticipated. Reports are of it dimming and of the nucleus disintegrating. It will be interesting to follow its progress over the coming days
  • On Wednesday and Thursday mornings, the waning Crescent Moon will pass by the line of the superior naked-eye planets: Mars, Jupiter and Saturn. Look in the southeastern pre-dawn sky
  • Monday April 13th is the 50th anniversary of those famous words: “Houston, we’ve had a problem…” when an oxygen tank blew two days in to the Apollo 13 mission, threating the lives of the astronauts aboard the spacecraft. Quick thinking, bravery and determination turned the threat of defeat into victory and the crew safely returned to Earth on April 17th
  • The Moon is waning and will be Last Quarter on Tuesday
  • There are currently no active regions on the Sun, with the spotless stretch now at 7 days
  • There are no visible evening ISS passes this week

Week of 6th April

  • Astronomical twilight ends at 21:51 BST at the start of the week and 22:06 BST at the end
  • As Orion appears ever closer to the western horizon, it is interesting to note that Betelgeuse is well on its way back to ‘normal’ brightness. Reports now suggest it is at magnitude +0.9. Have a look for yourself before it is too late and see how much brighter it now appears
  • Mars, Jupiter and Saturn are a treat for the early risers as they appear in a line across the southeastern pre-dawn sky within 15° of eachother
  • The Moon is waxing and will be Full on Wednesday
  • There is one active region on the Sun, AR 2759. It is at a high northerly latitude and has reversed magnetic polarity, identifying it as a member of new Solar Cycle 25
  • There are no visible evening ISS passes this week

March 2020 What’s Up!

Week of 30th March

  • Astronomical twilight ends at 21:35 BST at the start of the week and 21:49 BST at the end
  • On Saturday evening, Venus will appear close to the Pleiades in Taurus, passing within about 15 arcminutes of the open cluster. Venus will be at mag -4.4 while the Pleiades will be at mag +1.3
  • For the early risers, the three naked eye superior planets, Mars, Jupiter and Saturn, make a spectacular sight as they all appear in the sky within 7° of eachother. Look towards the southeast horizon at around 5am. On Tuesday and Wednesday mornings, Mars and Saturn will be within 1° of eachother, around this time appearing in conjunction when they share the same right ascension
  • The Moon is waxing and will be First Quarter on Wednesday
  • There are no active regions on the Sun, with the current spotless stretch at 19 days
  • There are multiple evening ISS passes this week:
    Monday: 21:32, W to S, max 46°
    Tuesday: 20:44, W to ESE, max 61° and 22:21, W to WSW, max 15°
    Wednesday: 21:34, W to SSW, max 25°
    Thursday: 20:46, W to SSE, max 34°
    Friday: 21:37, WSW to SSW, max 12°
    Saturday: 20:49, W to S, max 18°

Week of 23rd March

  • Astronomical twilight ends at 20:21 UT at the start of the week and 21:33 BST at the end
  • British Summer Time starts on Sunday 29th March, clocks go forward one hour at 1am
  • Venus is at Greatest Eastern Elongation on Tuesday, when it is at maximum separation from the Sun. It reaches a peak altitude of 41° above the horizon on Friday evening, shining at mag -4.4. Observation of Venus through binoculars or a telescope at this time will show it in dichotomy phase, the equivalent of a Quarter Moon phase
  • Mercury is at Greatest Western Elongation on Monday, appearing before sunrise in the southeastern morning sky. Unfortunately it will be difficult to spot at only 6° above the horizon. Take care of the rising Sun if you do try to spot it. Mercury will be at aphelion on Friday, the furthest point from the Sun in its orbit
  • A new comet, C/2019 Y4 (Atlas), was discovered in December last year and is brightening as it approaches the Sun. It is currently at magnitude +8.3, so binoculars are needed to see it. Look above the head of the Bear in Ursa Major. It will reach perihelion on 31st May, so will hopefully become increasingly bright through the spring. For full details about this comet, visit theskylive.com and search for ATLAS
  • The New Moon is on Tuesday
  • There are no active regions on the Sun, with the current spotless stretch at 11 days
  • There are multiple evening ISS passes this week:
    Monday: 19:36, WSW to E, max 55° and 21:13, W, max 27°
    Tuesday: 20:25, W to ENE, max 88°
    Wednesday: 19:38, WSW to E, max 84° and 21:15, W, max 30°
    Thursday: 20:27, W to E, max 86°
    Friday: 19:40, W to E, max 84° and 21:17, W, max 29°
    Saturday: 20:29, W to SE, max 76°
    Sunday: 20:42, W to E, max 87° and 22:19, W to WSW, max 24°

Week of 16th March

  • Astronomical twilight ends at 20:07 UT at the start of the week and 20:19 UT at the end
  • The Vernal Equinox is on Friday and marks the first day of spring here in the Northern Hemisphere. It is the point when the Sun, travelling along the ecliptic, crosses the celestial equator, heading North and has a Right Ascension of 00 hours and a Declination of 0°. It is also known as the First Point of Aries; however, due to Earth’s precession, the Sun is no longer in Aries at this time, but is in Pisces – apologies to all those who swear by their daily horoscope!
  • The Moon is waning and will be Last Quarter on Monday
  • There are no active regions on the Sun, with the current spotless stretch at 5 days
  • There are multiple evening ISS passes this week:
    Thursday: 19:33, S to SSE, max 15°
    Friday: 20:21, SW to SSW, max 30°
    Saturday: 19:33, SSW to ESE, max 30° and 21:10, WSW, max 19°
    Sunday: 20:22, WSW to SSE, max 69°

Week of 9th March

  • Astronomical twilight ends at 19:53 UT at the start of the week and 20:05 UT at the end
  • Venus continues to appear high in the southwest evening sky at magnitude -4. It will be about 2° from Uranus (mag +6, binoculars required) at the start of the week
  • The Moon is waxing and will be Full on Monday
  • Breaking a string of 34 spotless days, a new sunspot is emerging in the Sun’s southern hemisphere. The high latitude and magnetic polarity of this sunspot identify it as a likely member of new Solar Cycle 25
  • There are no visible evening ISS passes this week

Week of 2nd March

  • Astronomical twilight ends at 19:41 UT at the start of the week and 19:52 UT at the end
  • Comet C/2017 T2 (PANSTARRS) is currently visible through a telescope at magnitude +9 in Cassiopeia
  • Venus is high in the southwest evening sky
  • The Moon is waxing and will be at First Quarter on Monday
  • The Sun has no visible active regions, current spotless stretch is 28 days
  • There are no visible evening ISS passes this week

February 2020 What’s Up

Week of 24th February

  • Astronomical twilight ends at 19:29 UT at the start of the week and 19:39 UT at the end
  • Venus is ever higher in the southwest evening sky
  • The waxing Crescent Moon will pass by Venus in the evening, appearing closest on Thursday when they will be about 6° apart. Look towards the southwest horizon to spot this appulse
  • Reports suggest that Betelgeuse has stopped dimming and could be increasing in magnitude again. Get out, have a look and see what you think
  • Star Count 2020 is running from the 21st to 28th February. It is a ‘Citizen Science’ project to assess light pollution levels across the country. Count the number of stars you can see by naked eye within the ‘four corners’ of Orion and report your observation online. Search ‘Star Count 2020’ for full details
  • The Moon is waxing and will be at First Quarter next week
  • The Sun has no visible active regions, current spotless stretch is 21 days
  • There are no visible evening ISS passes this week

Week of 17th February

  • Astronomical twilight ends at 19:17 UT at the start of the week and 19:27 UT at the end
  • Venus continues to dominate the southwest evening sky
  • For the early risers, the waning Crescent Moon will appear close to Mars on Tuesday, Jupiter on Wednesday and Saturn on Thursday. Look in the southeast at around 6 am
  • The Moon will be New on Sunday
  • The Sun has no visible active regions, current spotless stretch is 14 days
  • There are no visible evening ISS passes this week

Week of 10th February

  • Astronomical twilight ends at 19:05 UT at the start of the week and 19:15 UT at the end
  • The Moon reaches perigee (closest point to Earth) on Monday; it is waning and will be Last Quarter on Saturday
  • Venus, the ‘Evening Star’, is bright (mag -4) and clear to spot in the southwest evening sky
  • Mercury (mag -0.5) will be at Greatest Eastern Elongation on Monday, placing it perfectly for a rare sighting. It will be at its highest point in the sky on Friday, when it reaches a peak altitude of 15° above the horizon. Look in the southwest just after sunset (take care as Mercury is still within 20° of the Sun)
  • Neptune is also in the southwestern evening sky, though at magnitude +8 will require binoculars to be seen. It is in close conjunction (about 2 arcminutes) with the star Phi Aquarii and comes to about 5° of Mercury
  • Keep observing Betelgeuse, which is at its dimmest since records began, currently at about magnitude +1.7. February 21st is a key date as this is when the star’s variable periods are predicted to turn and it should start to brighten again
  • The Sun is currently spotless
  • There are no visible ISS passes this week

Week of 3rd February

  • Astronomical twilight ends at 18:54 UT at the start of the week and 19:04 UT at the end
  • The Moon is waxing and will be Full on Sunday
  • Venus is climbing ever higher in the southwest evening sky
  • Mercury is starting to become visible in the evening sky, look low on the southwestern horizon just after sunset (take care as Mercury is still within 20° of the Sun)
  • The Sun has one current active region (AR 2757), which is departing around the western limb
  • The ISS makes visible evening passes this week as follows:
    Monday: 18:31, W to E, max 87° & 19:08, W to S, max 34°
    Tuesday: 18:21, W to SE, max 46° & 19:59, WSW to SW, max 12°
    Wednesday: 17:33, W to ESE, max 60° & 19:10, W to S, max 17°
    Thursday: 18:22, W to SSE, max 24°
    Saturday: 18:25, WSW to SSW, max 12°

January 2020 What’s Up!

Week of 27th January

  • Astronomical twilight ends at 18:44 UT at the start of the week and 18:53 UT at the end
  • There is an unusual conjunction of Neptune (mag +8) and Venus (mag -4) on Monday evening. Look low in the southwest sky between 17:00 and 19:30 UT to see the two planets just 4 arcminutes apart. You will need to use a pair of binoculars or a telescope to observe the conjunction. On Tuesday evening, the Crescent Moon comes within 4 degrees of the pair, making an interesting combination to look out for
  • The Moon is waxing and will be First Quarter on Sunday
  • Look to the southwest just after sunset to see Venus dominate the twilight sky at mag -4.0
  • The Sun has one Cycle 24 active region near the equator (AR 2757). A region of interest belonging to Cycle 25 is developing high in latitude around the southeast limb
  • There are multiple visible evening ISS passes this week as follows:
    Monday: 18:14, WSW to E, max 72°
    Tuesday: 17:26, WSW to E, max 57° & 19:03, W to WNW, max 70°
    Wednesday: 18:16, W to E, max 87° & 19:52, W, max 20°
    Thursday: 17:28, WSW to E, max 85° & 19:05, W, max 73°
    Friday: 18:17, W to E, max 86° & 19:54, W, max 20°
    Saturday: 17:30, W to E, max 84° & 19:07, W to SSW, max 60°
    Sunday: 18:19, W to ESE, max 75° & 19:56, W to WSW, max 18°

Week of 20th January

  • Astronomical twilight ends at 18:34 UT at the start of the week and 18:42 UT at the end
  • Betelgeuse continues to appear dimmer than its normal magnitude of +0.5. Compare with Rigel (+0.3) and Bellatrix (+1.6). The lower brightness is only in the visible wavelengths, in infrared it continues to shine as brightly as ever
  • The Moon is waning and will be New on Friday
  • Venus continues to dominate the western evening twilight sky at mag -4.0
  • The Sun has no spots, with a current spotless stretch of 7 days
  • There are multiple early evening ISS passes this week as follows:
    Wednesday: 18:59, SW to S, max 25°
    Thursday: 18:11, SSW to ESE, max 23°
    Friday: 17:24, S to E, max 16° & 18:59, WSW to SSW, max 47°
    Saturday: 18:11, SW to E, max 42°
    Sunday: 17:23, SSW to E, max 31° & 18:59, WSW, max 70°

Week of 13th January

  • Astronomical twilight ends at 18:25 UT at the start of the week and 18:32 UT at the end
  • Betelgeuse, the red giant star at Orion’s left shoulder, has dimmed significantly since the autumn. Normally it shines at magnitude +0.4, but it is currently at mag +1.4, about two and a half times dimmer. Compare its brightness with the star at Orion’s right heel, Rigel, which is mag +0.3 and the difference is very clear. Many theories about what is causing the change abound, but the most widely accepted is that Betelgeuse, as a variable star, is experiencing a period of swelling, which leads to its luminosity being spread across a larger surface area, therefore appearing dimmer to us
  • The Moon is waning and will be Last Quarter on Friday
  • Venus continues to dominate the evening twilight sky at mag -4.0
  • The Sun is currently spotless again after a recent period of increased activity
  • There are no evening ISS passes this week

 

Week of 6th January 2020

  • Astronomical twilight ends at 18:17 UT at the start of the week and 18:23 UT at the end
  • Watch The Sky at Night at 10pm on BBC4 next Sunday (12th) to see CEB and observing on the College playing fields feature
  • There is a penumbral Lunar eclipse on Friday 10th as the Full Moon passes through the faint outer edge of the Earth’s shadow (the penumbra). Maximum eclipse occurs at 19:11. It will not be very obvious to the naked eye, but comparative photos will show the difference
  • The Moon is waxing and will be Full on Friday
  • Venus continues to dominate the evening twilight sky
  • The Sun has one, reversed polarity, Cycle 25, active region (AR2755)
  • There are no evening ISS passes this week