This Week’s Sky: January 14 – 21

A widely visible total lunar eclipse is one of the year’s biggest astronomical highlights.

Lunar eclipse by Gary Seronik

SkyNews editor Gary Seronik recorded this view of the January 2018 total lunar eclipse.

All Week

Facing southeast, one hour before sunrise.

The view facing southeast, one hour before sunrise.

Mars continues to have the evening sky all to itself as the lone planet, and at magnitude 0.7, readily outshines the stars nearby. That, and its distinctive colour, make Mars easy to spot slightly west of due south at dusk. Meanwhile, the dawn sky sports a pair of very prominent planets. First up is Venus, the reigning morning “star,” which rises around 4:15 a.m., local standard time. At magnitude –4.5, it’s impossible to mistake Venus for anything else. Sadly, its naked-eye splendour isn’t matched by telescopic impressiveness. With enough magnification, all one generally sees is a snow-white disc exhibiting a moonlike phase. Not far behind Venus is Jupiter, which clears the southeast horizon a little more than a ½ hour later. Jupiter shines at magnitude –1.8 and attains an altitude of 15 degrees in bright morning twilight. Unlike its glaring neighbour, Jupiter offers lots of detail in a telescope, but only when it climbs higher. It’s still very early in the current Jovian apparition—it’ll be several more weeks before we can productively turn our telescopes on Jupiter once again.

January 14

The Moon reaches first-quarter phase today at 1:45 p.m., EST.

January 17

The Moon and Aldebaran

The Moon and Aldebaran as seen from Toronto, Ontario, in 10×50 binoculars.

This evening the waxing gibbous Moon shares the same binocular field as first-magnitude Aldebaran, the brightest star in Taurus. The earlier you look, the closer they will appear. Viewed from Toronto, Ontario, the lunar disc sits just three degrees from Aldebaran at nightfall. By the time twilight fades on the West Coast, they’ll be 1½ degrees farther apart.

January 20/21

Lunar Eclipse of January 20-21, 2019, Diagram by Glenn LeDrew for SkyNews

SkyNews diagram by Glenn LeDrew.

The Moon is full at 12:16 a.m., EST, (January 21). But that won’t be what grabs the headlines. Rather, it’ll be a total lunar eclipse resulting from the Moon passing through Earth’s shadow for the first time since January 31, last year. This much publicised event will be visible all across North America, weather permitting. As shown in the diagram above, the lunar disc is completely immersed in the darkest part of Earth’s shadow (the umbra) from 11:42 p.m. to 12:44 a.m., EST, and mid-eclipse occurs at 12:13 a.m., EST. The only slight complication is that, depending on which time zone you’re in, the eclipse straddles midnight, which means it happens on the night of the 20th and extends into the morning of the 21st. If you go out on the evening of the 21st instead, you’ll miss the eclipse entirely and just see a nearly full Moon. Despite the season’s cold temperatures, you’ll want to make an effort to catch this eclipse. Not only is it arguably 2019’s most interesting celestial sight, for Canadians it’s also the last total lunar eclipse until May, 2022.

For much more on the event, turn to page 27 of the January/February issue of SkyNews.

Weekend Stargazer

Reiner Gamma Chart

Use this illustration to locate Reiner Gamma (SkyNews chart using LRO image.)

With the full Moon occurring as Sunday night transitions into Monday morning, evenings over the January 18 – 20 weekend are obviously going to be awash in moonlight. So why not give in and enjoy a look at the Moon? It’s nicely positioned high on the ecliptic and visible pretty much all night long. And if you’re up for a slight challenge, we have one for you: Reiner Gamma.

Aim your telescope at the western edge of Oceanus Procellarum (remembering that east and west on the Moon are the reverse of sky directions), and scan just a little northwest of a 29-kilometre-diameter crater named Reiner. There you’ll find Reiner Gamma, a curious, light-hued tadpole shaped marking. Unlike topographical features (such as craters and rilles) that appear most striking when the terminator is nearby, Reiner Gamma is best seen under a high sun. The ideal time to look is when the Moon is nearly full and several days after.

What is Reiner Gamma? It’s categorized as a swirl, which tells you almost nothing about its true nature. But the fact is, very little is known about lunar swirls. We don’t really know how they formed or why they appear the way they do. One thing that is known, however, is that swirls have intense magnetic fields. Indeed, Gamma Reiner possesses the strongest magnetic field of any feature on the Earth-facing side of the Moon. But what does that mean? That’s the $64,000 question. Regardless, the Reiner swirl is an interesting and unique telescopic sight—one definitely worth adding to your lunar life list!

At SkyNews we love to read about your experiences and see your photos. You can share them with us by e-mailing [email protected].

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