"Tonight's Sky" is written by retired planetarium director Dave Leake and reprinted with his permission. See Dave Leake's Prairie Skies column in the Champaign–Urbana News-Gazette each Sunday. Dave Leake's preview of 2020 sky events can be found here.
Thursday’s waxing gibbous Moon rises just below the reddish planet Mars. By Halloween the Moon is full, our second full Moon of the month. Historically we’ve called this a “blue Moon”, but know the Moon isn’t blue. The definition of "blue Moon" has changed over the years. Since we usually have one full Moon per month, there are three per season. In fact, this is our basis for the “month,” or “moonth”! If there’s a fourth, the term usually applied to the third of the four. The most recent definition resulted from an error in a 1946 magazine article. Two full Moons in a month will happen again in August 2023. The Moon won’t look any different but check it out anyway!
You’ve heard many say "follow the science". Keep in mind that science isn’t a thing; it’s a process, a "dog-eat-dog" process. When someone produces a result from an experiment, there are teams trying to replicate the result with the intent of proving it wrong. The result that survives gains consensus in the scientific community. This process takes time. Normally research teams beat each other up until that consensus exists and only then are results announced. Today it’s different, especially with the internet and social media. Today the public is along for the entire ride. So when you hear "scientists have changed their minds", yes, that’s part of the process. The result with the best evidence wins. Vote Tuesday!
Early risers have a treat this week as we have an excellent morning view of Mercury along with Venus. The greatest separation from the Sun’s glare occurs on Tuesday morning. Look in the east-southeast just before 6 a.m. Venus will appear like a brilliant star. Right below it is the bluish star Spica. Mercury will be to the lower left of Spica. On Thursday morning, a thin crescent Moon will sit above Venus. The orange star Arcturus will be far to the left of the Moon. On Friday morning the Moon is placed between the two planets. If you’re up walking the dog, watch how Venus appears to close in on Spica with the two being side-by-side on Wednesday morning of next week.
This weekend’s new Moon means we’ll spy a crescent Moon in the southwest early this week. When will you first see it? Start looking tomorrow evening. Each night the Moon will approach our pair of planets in the south until Thursday evening, when the Moon makes a nice triangle with Saturn and the brighter Jupiter. Keep an eye on these two planets as they gather next month in a conjunction that occurs once every twenty years.
The Leonid meteor shower peaks Tuesday morning when the Earth crosses the path of Comet Tempel–Tuttle. The Leonids have impressed in the past (3000 meteors per hour were estimated in 2002) but no more than 10-15 per hour are expected this year.
The Moon treks eastward each night and on Wednesday evening, you can see it in a waxing gibbous phase below the planet Mars. “Waxing” means “to increase”, meaning we see more of the Moon’s lit surface on successive nights. Lower in the northeast at sunset you might see the star Capella. Take your binoculars and find Capella then pan to the right, along the horizon, and see if you can pick up the Pleiades or Seven Sisters star cluster, looking like a miniature dipper. The Pleiades are a wonderful star cluster, mentioned throughout history and have even served as a calendar to some Native American tribes, but the cluster’s appearance in the evening sky means cold weather is around the corner!
However you celebrate this week, I hope you have a wonderful Thanksgiving!
November 29 – December 5
The Full Moon rises just before 4:30 p.m. tonight in the east-northeast. After midnight, careful observers have a chance to see a penumbral lunar eclipse. The Earth has two shadows given the Sun is a large light source (not a point source) and the Moon will move through the lighter part beginning at 1:32 a.m. At 3:43 a.m, 83% of the Moon will be in the penumbral shadow and the event is over just before 6 a.m. Unlike an umbral eclipse, this shadow will result in a light shading of the Moon’s surface and you may have trouble noticing it. Look carefully for the shadow line along the lower portion of the Moon.