The new year kicks off with a bit less fanfare than 2020 gave us. January will be somewhat boring compared to December although it was frustrating to know that an occultation, the Geminid meteors and the Jupiter-Saturn conjunction, were all occurring beyond a total overcast, complete with lots of rain!
Nevertheless, Mercury rounded the far side of the Sun on Dec. 19 and is moving east daily. This will make it visible in the southwest just after sunset by about Jan. 10, depending on haze, clouds and so forth. Mercury will reach its greatest eastern elongation on the evening of the 23rd and should be visible all month even as it approaches Earth and begins to swing around in front of the Sun. Interestingly, Jupiter and Saturn will disappear behind the Sun in late January but they may be visible along with Mercury until possibly the 15th. All of this will happen in the glow in the southwest immediately after the Sun goes down. Saturn will be closest to the Sun; left and above it will be Jupiter, then Mercury and, on the 14th, the Moon. While it’s quite possible to see all three planets during daylight with binoculars, at this time they’re all too close to the Sun to take the risk of severe and permanent eye damage should you accidentally wind up looking at the Sun. Remember, ordinary binoculars are capable of starting a fire if you aim them at the Sun and have something flammable at the focal point of the eyepieces. Your retinas are much more sensitive and quite irreplaceable so don’t take the chance, please.
Another subtle astronomical effect will happen around the 13th. Earth is at perihelion – its closest approach to the Sun – in our slightly elliptical orbit on Jan. 2 and the Moon is at perigee on Jan. 9. Tidal forces are inversely proportional to the cube of the distance between bodies so by the New Moon on the 13th we may well see tidal ranges a bit bigger than the usual New Moon / full Moon extremes. Although the Earth’s distance from the Sun doesn’t vary by much, only about 3% of the mean orbital radius, that’s also enough to affect the nature of solar eclipses. The angular size of the Sun and the Moon are so close that we see more total eclipses around July when we’re farther away from the Sun and more annular eclipses around January when we’re closer to the Sun. The “Heavens Above” website at: www.heavens-above.com will show you a star chart for anyplace/anytime to check out all the above events, as well as a lot of other info. The next Zoom meeting of the Astronomy Club will be Jan. 8 at 7 p.m.; the speaker will be Michael Bradley of the Sunshine Coast Astronomy Centre of the RASC. Michael will be speaking about our Sun coming out of its solar minimum, techniques and equipment for viewing it and some of the members’ photos of the Sun. The club website at: https://sunshinecoastastronomy.wordpress.com/ will have information on the speaker and topic and how to register for the meeting the week prior.
– Richard Corbet
