Science
CONJUNCTION MONTH! If there’s nothing else you do this month, mark your calendar, get your warm clothes set aside, and get ready for a very, very rare conjunction between Jupiter and Saturn on the 21st. More details to come. If you do more than that one thing, we also have another meteor shower and some good close encounters between the Moon and the planets. Welcome to Observing With Webb, where a high school astronomy teacher tells you what you’re looking at, why it’s so cool, and what you should check out later this month…at night. Naked-eye PLANETS... Sunset – Saturn, Jupiter Saturn, Jupiter (S) – Jupiter and Saturn bow out for the year with a glorious finale. By the end of the month, these two will set just after sunset, but until then, just look Southwest after sunset, but before 8pm and find the two really bright points of light fairly close together. Jupiter will be the brighter one. KEEP WATCHING day after day, and you’ll notice them getting noticeably closer every day, until the 21st when they are 1/10th of one degree apart. This is a very rare event and something that everyone needs to go out and see. Watch the sunset, look southwest, and enjoy the view. More on this in the events section. Throughout the night – Mars Mars (SEàSàW) – Look SE after sunset to find the non-twinkling reddish-orange dot, much brighter than everything around it. Sets around 2 or 3am in the West. Morning – Venus Venus (E) – Venus rises in the East after 5am on Dec 1st, and after 6am on the 31st. Bright, brilliant, and gorgeous. Get your looks in now, since it dives closer and closer to the Sun through December, and stays close to the Sun until Summer of 2021. EVENTS... Waning Gibbous (Mostly lit, rises later at night) Last Quarter Moon – 7th (Visible from midnight into the morning) Morning Crescents (look East in the AM) New Moon – 14th (darkest skies) Evening Crescents (look West after Sunset) First Quarter Moon – 21st (Visible until midnight) Evening Gibbous (Mostly lit, after Sunset) Full Moon – 30th (Visible all night) 12th – Close Encounter – Moon, Venus – Get up early on Saturday morning and make sure you have a nice view of the SE horizon between 5:30am and 7:00am. Venus and the Moon should be easy to spot, with Venus being VERY bright, and the Moon being a thin beautiful crescent. 13th, 14th – Geminid Meteor Shower – This is a VERY good year for the Geminids. We have no Moon in the sky and the peak will occur during the evening hours on Sunday the 13th. So get out there after dinner and take advantage of the possible 150 meteors per hour! But be well prepared… When? The peak is the night of December 13th, 2am local time Where do I go? Dark area, away from lights, comfortable chair, pool float, hammock. Where do I look? The whole sky, but note Gemini is where the radiant is - where the meteors will appear to be coming from. Gemini will be in the East after sunset, South after midnight, West in the morning. Check the weather to see if the skies will be clear BUNDLE UP! Far more layers than you think. Adapt your eyes to the dark by staying away from light sources for 20 minutes or using a red light if you need to look at a star chart or not trip over something. If you’re feeling extra nerdy, do a scientific meteor count (S&T and IMO) 14th – You might hear some things about a total solar eclipse, but it’s in Chile and Argentina. 21st – CONJUNCTION OF JUPITER AND SATURN – This only happens every, say, couple hundred years. Jupiter and Saturn will be within 1/10th of 1˚ of each other! This is the event of the month, perhaps even the year. They will be close to each other for most of the month, but they will be closest on the night of the 21st. How do you see it? Get dressed VERY warmly, and head outside after sunset (4:42pm) Look SW, where the sun just set. Jupiter and Saturn should appear fairly quickly as the first two objects you see in the night sky just 15˚ (1.5 fist-widths) above the horizon. Don’t waste your time getting out there, though. The pair sets below the horizon before 7pm, leaving you not more than an hour and half of viewing time, if your horizon is fairly flat and unobstructed. Definitely bring binoculars, but enjoy the entire sky. If you have a telescope, you can get both the planets in the same eyepiece view! 21st – Winter Solstice - The longest night and shortest day of the year for the Northern Hemisphere. More info here: http://www.timeanddate.com/calendar/december-solstice.html 23rd – Close Encounter – Moon, Mars – Get out there after sunset but before 2am and find the waxing Gibbous Moon in the SE with red, ruddy Mars close and bright just 5˚ above it. CONSTELLATIONS... Use a sky map from www.skymaps.com to help you out. After Dinner: Cassiopeia, Andromeda, & Perseus - Look pretty much straight up you’ll be able to see Andromeda curving off of one corner of Pegasus. If your skies are decently dark, you might catch the faint fuzz that is the Andromeda Galaxy. Cassiopeia will be relatively easy to find as the “W” in the sky, whose right angle points right to Andromeda and her galaxy. Perseus is the other cornucopia-shaped constellation, but opposite of Andromeda, with its curves emptying out toward the Pleiades Before Bed: Taurus & the Pleiades – Look almost straight up, but down toward the South a little bit and you’ll find the lovely cluster of stars known as the Pleiades, the Seven Sisters, Subaru, or the mini-mini-dipper. You can easily see 5 or 6 of them with the unaided eye, and perhaps a 7th, depending on light pollution and your eyes. To the left about 5˚ will be the V constellation of Taurus the bull, with bright red Aldebaran as its brightest, and one eye of the bull. Oh, and if you follow a line connecting these two to the left about 10˚, you’ll find Orion. Before Work: Leo – Look South, halfway up the sky, to find the backward question mark and right triangle that is Leo the Lion. Don’t forget this podcast is found on my Podbean page, Stitcher, and iTunes. There’s also a video version on my YouTube Channel and I can be found on Twitter and Instagram as @mrwebbpv. The Pequea Valley Planetarium and its events and updates are on Facebook, Twitter, and Instagram as @pvplanetarium.