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
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