
Cancer


Seek out 1998 OR2, the brightest predicted near-Earth asteroid encounter of 2020
A near-Earth object (NEO) and potentially hazardous asteroid (PHA) with the catchy official name of 52768 (1998 OR2) passes just 16.4 lunar distances (6.3 million kilometres) from Earth at 09:56 UT on Wednesday, 29 April 2020. Here’s our guide to locating this fascinating asteroid in 15-cm (6-inch) aperture telescopes and smaller from the UK this month.



See the Moon buzz the Beehive Cluster on 10-11 May
UK skywatchers with a view low to the west between midnight and moonset on Saturday, 11 May 2019 can see the 6-day-old waxing crescent Moon close to Messier 44, otherwise known as Praesepe, or the Beehive Cluster. Later, observers on North America’s Eastern Seaboard can see the Moon pass in front of this glorious open cluster just before local midnight on 10 May.

See Comet Iwamoto’s dash through Leo, Cancer and Gemini before full Moon
Grab your binoculars to catch a glimpse of speedy Comet C/2018 Y1 Iwamoto over the coming week before the glare from a full Moon on 19 February drowns it out. Potentially attaining magnitude +6, the comet passes closest to Earth on 12 February when it can be found traversing Leo at a rate of 7.2 degrees/day. Don’t miss C/2018 Y1’s close enounter with galaxy NGC 2903 on 13 February – by eye, camera, or live online.

A viewing guide to the totally eclipsed supermoon of 21 January
While you may not relish the prospect of waking up in the small hours most Monday mornings, observers in the British Isles and Western Europe will want to set their alarms no later than 5am GMT on 21 January to see this month’s showstopper celestial event — a total lunar eclipse of an unusually close ‘supermoon’. The total lunar eclipse is also visible in its entirety (weather permitting) from the Americas.

See innermost planet Mercury’s favourable dawn show
Mercury attains its maximum westerly elongation from the Sun on 26 August, meaning that the innermost planet is currently well placed for observation from the UK and Western Europe in the eastern sky around 40 minutes before sunrise. In addition to those in the evening sky, you might just see all five bright naked-eye planets this month!

See bright near-Earth asteroid 2002 AJ129 dash through Virgo and Leo, 5–7 February
Possibly a kilometre or more in size, Apollo asteroid 2002 AJ129 passes just 10.9 lunar distances from Earth at 21:30 UT (9:30pm GMT) on 4 February — its closest approach for 114 years. For a few nights around this date the magnitude +12.6 body is well placed for observers as it gallops through the constellations of Virgo and Leo into Cancer at a rate of up to 40 degrees/day. We show you where and when to look for it.

See dwarf planet Ceres at opposition on 31 January
While antipodean observers are enjoying views of the totally eclipsed Blue Moon in Cancer the Crab on the night of 31 January/1 February, Northern Hemisphere observers should look out for magnitude +6.9 1 Ceres at opposition in the northern fringes of the same constellation. The dwarf planet puts on a good show in the dark of the Moon during February.