January 2023 – What’s Up!

Week of 30th January

  • Astronomical twilight ends at 18:48 GMT at the beginning of the week and at 18:58 GMT by the end of the week.
  • Comet C/2022 E3 (ZTF) reaches perigee, its closest approach to Earth on Thursday, when it will be about 0.28 AU away or approximately 42,500,000 km. Travelling at around 57 km/s with respect to the Earth, it is climbing ever higher above our northern horizon, starting the week near Polaris and by the end of the week it will have just passed the zenith to appear near to Capella in Auriga. It has reached a reported brightness of about magnitude +5.5. It could be visible by naked eye, but the bright moonlight will hinder our view. Search for the comet in binoculars or a telescope.
  • Mercury (-0.1) reaches Greatest Western Elongation on Monday, appearing a maximum of 10° above the southeastern horizon just before sunrise at 07:48 GMT. Take care of the rising Sun if looking for Mercury in binoculars or a telescope.
  • The Moon is Full on Sunday – the Snow Moon.
  • The Sun currently has six active regions and the sunspot number is 76.
  • There are multiple visible evening ISS passes this week as follows:
    Monday: 17:29 (-3.7) W to ESE, max 86° & 19:06 (-2.4) W to S, max 33°
    Tuesday: 18:17 (-2.8) W to SE, max 46° & 19:55 (-0.6) WSW to SW, max 12°
    Wednesday: 17:28 (-3.2) W to ESE, max 61° & 19:06 (-1.2) W to S, max 18°
    Thursday: 18:17 (-1.6) W to SSE, max 25°
    Saturday: 18:17 (-0.7) WSW to SSW, max 13°

Week of 23rd January

  • Astronomical twilight ends at 18:38 GMT at the beginning of the week and at 18:47 GMT by the end of the week.
  • Look out for Venus (mag -3.9) around sunset; it is increasing in altitude and can be seen approaching 15° above the southwestern horizon at about 17:00 GMT by the end of the week. It sets by about 18:45 GMT.
  • Comet C/2022 E3 (ZTF) is now around mag +6 and increasing in brightness, but is quite difficult to spot in the thicker atmosphere close to the northern horizon. It climbs ever higher this week and by Friday will be at an altitude of about 40°; look just to the east of star Kochab in Ursa Minor, binoculars will help, but it could reach naked eye visibility.
  • The Moon is First Quarter on Saturday.
  • The Sun currently has ten active regions and the sunspot number is 194.
  • There are multiple visible evening ISS passes this week as follows:
    Monday: 18:19 (-3.8) WSW to E, max 76° & 19:56 (-0.6) W, max 15°
    Tuesday: 17:30 (-3.5) WSW to E, max 61° & 19:07 (-3.0) W, max 52°
    Wednesday: 18:19 (-3.8) W to E, max 86° & 19:55 (-0.7) W, max 16°
    Thursday: 17:30 (-3.7) W to E, max 87° & 19:07 (-3.2) W, max 58°
    Friday: 18:18 (-3.8) W to E, max 87° & 19:55 (-0.8) W, max 17°
    Saturday: 17:30 (-3.8) W to E, max 84° & 19:06 (-3.2) W to SW, max 56°
    Sunday: 18:18 (-3.7) W to ESE, max 74° & 19:55 (-0.8) W to WSW, max 17°

Week of 16th January

  • Astronomical twilight ends at 18:29 GMT at the beginning of the week and at 18:37 GMT by the end of the week.
  • Mars (mag -0.6) and Jupiter (-2.3) continue to dominate our evening sky, but Jupiter is slipping ever further west and sets at around 22:30 GMT this week, so observe the planet while it is still well placed.
  • Comet C/2022 E3 (ZTF) is steadily brightening and is now about mag +6.6, close to naked eye visibility. It is low to the northern horizon in the evening, but should be easy to spot with binoculars, especially later in the night as it climbs in altitude.
  • On Sunday, Venus (-3.9) and Saturn (+0.8) will appear just under half a degree apart from each other, easily fitting in the same field of view through binoculars or a telescope. Look close to the southwestern horizon just after sunset.
  • The Moon is New on Saturday.
  • The Sun currently has nine active regions and the sunspot number is 170.
  • There are multiple visible evening ISS passes this week as follows:
    Tuesday: 18:21 (-1.4) S to SSE, max 13°
    Wednesday: 19:07 (-1.7) SW to SSW, max 22°
    Thursday: 18:19 (-2.5) SSW to SE, max 26° & 19:55 (-0.4) WSW to WSW max 12°
    Friday: 17:31 (-1.8) S to E, max 18° & 19:06 (-2.5) WSW to SW max 38°
    Saturday: 18:17 (-3.3) SW to ESE, max 47° & 19:54 (-0.5) W max 14°
    Sunday: 17:29 (-2.7) SW to E, max 34° & 19:05 (-2.9) W to WSW max 51°

 

Week of 9th January

  • Astronomical twilight ends at 18:20 GMT at the beginning of the week and at 18:27 GMT by the end of the week.
  • Lunar libration in latitude means that the southern polar region of the Moon is tilted favourably towards Earth, allowing a view of some craters that are not normally visible, such as Cabeus and Scott.
  • Comet C/2022 E3 (ZTF) continues to climb higher in the northeastern sky at magnitude +7. It is currently in Corona Borealis and will move into Bootes as the week progresses. Look low to the horizon with binoculars in the late evening to try and spot the comet.
  • The planets continue to cover our southern evening sky, with Venus (-3.9) visible close to the horizon in the west just after sunset, Saturn (+0.8) is now very low in the west and sets at 19:17, Jupiter (-2.3) dominates the western sky and Mars (-0.9) dominates the south. Mars appears to standstill on Thursday as its motion moves from retrograde to prograde, when it will appear to move eastwards again.
  • The Moon is Last Quarter on Sunday.
  • The Sun currently has five active regions: AR 3177, 3180, 3181, 3182 & 3183. The sunspot number is 104.
  • There are no visible evening ISS passes this week.

 

Week of 2nd January

  • Astronomical twilight ends at 18:13 GMT at the beginning of the week and at 18:19 GMT by the end of the week.
  • The Quadrantid Meteor Shower peaks in the early hours of Wednesday morning. It is one of the more spectacular showers of the year and can produce over 100 meteors per hour. However, this year the nearly Full Moon will block out all but the brightest. The shower’s parent body is asteroid 2003 EH1.
  • Earth reaches perihelion at 16:17 GMT on Wednesday, when it will be at its closest point to the Sun in its orbit at just 0.9833 AU away. What little Sun we see that day will be the largest in the sky of the year, but only by about 3%!
  • Look out for comet C/2022 E3 (ZTF), which reaches perihelion on Thursday. It is currently about mag +8.0 in the constellation of Corona Borealis, visible in binoculars in the northeast from about 01:00 GMT. It could brighten as an evening object as it heads north through January and into February.
  • The Moon is Full on Friday – the Wolf Moon. As the Moon will also be at apogee, its furthest orbital point from Earth, it will be the opposite of a ‘Supermoon’, a ‘Micromoon’.
  • The Sun currently has five active regions: AR 3173, 3176, 3177, 3179 & 3180. The sunspot number is 82.
  • There are no visible evening ISS passes this week.

 

in What's Up