Click here to go ahead to Winter 2013, or click here to go back to Summer 2012 "Eyes on the Sky" astronomy videos.
Jupiter, the Moon, the Hyades and Aldebaran are all nestled up close to each other on Christmas day. Hopefully the clouds stay away for you so you can see this tight grouping of celestial objects. And check out the "Best of Eyes on the Sky" for 2012 later in the video too.
Here's the sequence of events for the dual moon transit across the fact of Jupiter
12:08 UTC, Ganymede'd disk starts its transit across Jupiter.
14:12 UTC, Ganymede's disk finishes its transit across Jupiter.
14:32 UTC, Ganymede's shadow starts to cross Jupiter.
15:56 UTC, Io's disk starts its transit across Jupiter.
16:34 UTC, Io's shadow starts to cross Jupiter.
16:34 UTC, ** Dual-shadow event starts at this time. **
16:50 UTC, Ganymede's shadow exits Jupiter's disk.
16:50 UTC, ** The dual-shadow event is completed. **
18:08 UTC, Io finishes ots transit of Jupiter.
18:46 UTC, Io's shadow exits Jupiter's disk.
Convert your time for Universal Time (this event will not be visible to most of North America, though the very end of it may be visible in western Europe).
Early in the evening this week, the Summer Triangle stars and their attendant constellations are still visible in the western sky - odd, in a way, given that the winter solstice also occurs this week on the 21st! But as winter progresses, these stars will drop out of view, and we find ourselves witnessing the brighter stars and constellations of winter. What can we expect to see?
So get prepared for those long nights, and plenty of bright stars in those skies to guide you to the fascinating celestial sights of winter.
Early this week, not only are Mercury, Venus and Saturn still somewhat close together, but the Moon joins the trio as well. Find out which planets can be spotted with the Moon through binoculars or a telescope. The asteroid Vesta reached opposition on Sunday, and this minor planet is easier to find and see than you might think - and, it's not far from Jupiter in the sky, which is currently settled in Taurus the Bull near the first magnitude star Aldebaran.
The Geminid meteor shower peaks on the 13 / 14 of this week, and is often the most prolific display of meteors across the whole year. Given the cold, be sure to bundle up, but if clear then don't miss this spectacular event as tiny bits of solar system dust from asteroid-like object Phaethon 3200 rain down through our atmosphere, making for slow-moving but bright meteors in our sky.
And lastly, the Moon "rounds the bend" across the Sun and returns to the evening sky, joining Mars on the 14th and 15th - see where our natural satellite will be in relation to the Red Planet in "Night Sky Notes."
Aries may be a small and largely dim constellation, but has some special significance in the night sky. Back when ancient astronomers believe that the stars were affixed to a "celestial sphere," the location of the "celestial prime meridian" needed a starting point. Find out how the term "First Point of Aries" came into being, what they point is now, and how you can easily find it in the night sky. Plus, there are some great double stars to see in Aries, so be sure to bring out that small telescope and aim it towards that part of the sky (it's not far from where Jupiter is now in Taurus, already a great area to be viewing at this time of year).
Ever seen Mercury in the sky? It's not as hard as you might think; the planet is a naked eye visible object. But you do need to know right where to look to have a better shot at finding it, as it always manages to stay embedded in the twilight glow of the Sun. Venus and Saturn can help you find the elusive little messenger planet - and learn what NASA's MESSENGER has found on Mercury too.
Aries star chart (see bottom of chart); look for Greek letters Lambda and Gamma
Venus and Saturn make for a stunning pair in the early morning sky, especially early in the week. But later on, Mercury races upward towards its last greatest elongation for 2012, while Venus sinks away from Saturn. Over in the evening sky, the Moon joins Jupiter mid-week, settling in near the "eye of the Bull" - the first magnitude star Aldebaran - in Taurus. All three are visible in binoculars, but with a small telescope, there are some interesting craters to spy on the Moon's eastern limb, a night or two after full phase. And after the Moon has exited the evening sky, look for Uranus (see chart below) or Neptune - our solar system's two outer planets can be spotted using simple binoculars from most areas. Lastly, Mars continues is slow meanderings through the sinking summer constellations.
High in the sky fairly early in the night, Jupiter is easy to see, being the 4th brightest object in the sky (after the Sun, Moon and Venus). It is also retrograding - or appearing to move backwards against the background stars due to Earth's motion. Find out how and why this occurs, and also how the mythology of Jupiter and the constellation it is in right now - Taurus - intertwine.
What else can you see this week? How about Venus and Saturn! Uranus! Neptune! Mercury! Lots of great things to see - learn how and where in this week's "Eyes on the Sky."
This week continues locating some of the double stars that William Herschel observed, including a fantastic blue and gold double in Andromeda. Also covered is how to find Messier 31 (M31), the "Great Andromeda Galaxy" by following a few simple star hops, as well as what's happening with the Moon, Mars, Venus and Jupiter all week long. Last week's video is below, and look in the text for that video to find the Herschel's Double Stars chart as well.
William Herschel was an astronomer in the late 1700's and early 1800's that had a profound impact on the world of astronomy, both then and now. He was a prolific and detailed double star observer, a premier telescope maker, and discoverer of a planet in our solar system. Thanks to the slow-changing nature of much of our Universe, see some of these same double stars that Herschel observed in Pegasus, Andromeda and Cassiopeia, while learning an easy way to "see" the zero hour of Right Ascension in the night sky (a line also known as the equinoctial colure - yeah, say THAT five times fast!). Thanks to the "easy measurements in the sky" technique of using your outstretched arm and hand, you can also learn how to easily see the location of Uranus in the night sky, and how to find it with simple binoculars - thought it looks marginally better in a telescope at higher magnification. All that and how and when to see Mars and Jupiter in this week's "Eyes on the Sky."
Want some more info on this week's Dark Sky Fact? Check out my blog post from November 4, 2012. Interested in more double stars? They're easier to see and observe from light polluted areas - check out these ones in Andromeda, Cassiopeia and Ursa Minor.
The Moon turns full this week, which may seem to many amateur astronomers like a terrible time to observe, but don't discount what you can see on the Moon! Craters abound, and the ones along the edge just after full can be a fantastic area to view. This week "Eyes on the Sky" look at the large craters Langrenus, Petavius, Vendelinus, Furnerius, and more. Check out the Moon chart attached to find those craters along with some down to 12km (8 miles!) across, and even the location of the Apollo 11 site.
Later in the week, Jupiter puts on a show as some of it's satellites create a "phantom shadow" on the surface of the planet as first Ganymede casts a shadow prior to transiting the planet early the morning of the 1st (visible to North American observers), and then Europa does it again on the evening of the 4th (visible in Europe). All that, plus where Mars and Venus can be seen this week too.
Places you can find out more about Jupiter's moons:
Calsky.com - this one is nice because you can se the orientation as you see it in your telescope
Jupiter 2.0 - Freeware that lets you see a telescopic view / graphic representation while also viewing where the satellites are from over Jupiter, to get a better 3-D perspective. Written in French, but not hard to figure out how to use.
Dues to Dave's unfortunate incident last week during his interview with Vlad Tepes, "Eyes on the Sky" is hosted by Vlad this week, leading the way to three more carbon stars, and a very bright and distinct "garnet" colored star. Along the way, there is a stop at a favorite autumn object: Messier 31, the Andromeda Galaxy. Before getting to any of those though, he takes viewers through the mythology of Cassiopeia, Cepheus, Andromeda and Perseus, and interesting story in it's own right. And with the Moon headed towards full, there are quite a few craters on the southern end of the Moon worth searching out as well, with an ironically named one as the highlight.
Want to find more? Check out this list of carbon stars.
What "Eyes on the Sky" tries to emphasize, perhaps more than anything in amateur astronomy, is having fun. Usually that emphasis is on being able to find things easily, and although this week is no different in that regard, we DID have a bit more fun putting this video together. Given that October is generally associated with Halloween, Dave "interviews" the "noted sky-watcher Vlad Tepes" (ahem!) to see what he thinks of some of the night sky's objects. Surprisingly, more than just the Moon came up - mostly redder-color stars in Pegasus that can be seen naked eye, with binoculars or a telescope.
Aquarius may be a dim constellation, but there are enough "bright-ish" stars around it to help amateur astronomers find some of the hidden gems within it's boundaries. Check between Pegasus, Fomalhaut and Altair (along with some help from stars in Capricornus) to located Messiers 2, 72 and 73. Last week Comet Hergenrother unexpectedly brightened up from magnitude 15 to magnitude 10 - basically, from outside the reach of amateur scopes, to within the reach of many! Sky and Telescope has a finder chart with stars down to 7.4, but a more detailed chart will help you locate the 10th magnitude dim smudge of light in a 6" scope or larger as it moves across the Flying Horse this week. Also, Jupiter is nearly stationary near NGC1746 and Venus gets a visit from the Moon late in the week too.
Algol is a star in the constellation Perseus that "winks" - fitting, given that it represents the eye of Medusa! Find out where to see this star, and how often it "winks" this week. Sky and Telescope magazine has a handy calculator here to help you determine when the minimum magnitude of Algol will occur on any given date. Jupiter is finally up above the horizon enough before midnight to make it a decent night-time target, and has some fantastic features worth looking for too, like the Great Red Spot, expanded North Equatorial Band, and of course the ever-changing Galilean moons placement.
What could be better than just simply "looking up" and enjoying the wonders of the night sky? Learn how to find and identify the major stars and constellations of autumn in this week's "Eyes on the Sky." No telescope required! Just look up and learn where many of the major summer shapes are (which are still hanging around), along with the dramatic Andromeda, Perseus, Cepheus and Cassiopiea. Plus, what to expect for the major naked eye planets coming up, and where Neptune and Uranus are, and can be found.
Uranus finder chart here. 3.4 MB, PDF format
Click here to choose from all 2012 "Eyes on the Sky" videos