The Great KENTUCKY Eclipse of August 21, 2017: Will the Weather Hold?
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For the past week you have been seeing lots of posts about tomorrow’s eclipse and about Hopkinsville, Kentucky, the town at the point of greatest eclipse (or, to be precise, near that point): Click here for Monday’s post on the eclipse. Click here for Wednesday’s. Click here for Friday’s. Click here for Saturday’s. Hopkinsville is also the place that Vatican Observatory Director Br. Guy Consolmagno is visiting for the eclipse. Of course, not everyone can make it to south-western Kentucky to see this eclipse. If you are unable to make it into the path of totality, you might be able to see totality “virtually”, because Hopkinsville has a live camera mounted up high to give a continuous view of the area. Check it out below: Of course, there will not be much to see of this eclipse if the weather is not good. As can be seen from the Monday-Saturday posts, the forecast for the eclipse has gone this way and … Continue reading

The Great KENTUCKY Eclipse of August 21, 2017: Reading the Signs
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Two days from the eclipse and I am in Hopkinsville. Anyone passing through, even if they did not know that there was an eclipse here, would know that a Big Event is taking place. The signs are everywhere. Some of those signs are the busy-ness of landowners along Kentucky State Highway 91 into town. The path traced by the moon’s shadow will move toward the South-East into Hopkinsville, roughly following KY-91. While driving KY-91 into town earlier today, my wife and I saw lots of farms preparing for the influx of people—some setting up to welcome visitors (“Eclipse parking $50” near the point of greatest eclipse), some seeking to keep visitors from tromping all over their crops (“POSTED: No Trespassing. Private Property.”) Another clear sign of a Big Event are all the streets that are closed off, and the many tents and vendors set up, right in central Hopkinsville. There are also a lot of actual signs pertaining to the … Continue reading

The Great KENTUCKY Eclipse of August 21, 2017: Hopkinsville as the Perfect Point
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The Catholic Astronomer’s Blogger-in-Chief, Br. Guy Consolmagno, Director of the Vatican Observatory, is in Hopkinsville, Kentucky for the big 2017 eclipse.  That, and the fact that I am from Kentucky, is why I am calling this the great KENTUCKY eclipse (check out Monday’s eclipse post, and Wednesday’s, too).  So what is the big deal about Hopkinsville? An eclipse occurs when the moon’s shadow sweeps across the surface of the Earth.  The general path of the shadow in this eclipse is as shown by the arrow in the figure below. But, “it’s complicated,” because the Earth is rotating while the shadow is moving, and because the Earth is a sphere.  Points on Earth’s surface are moving from West to East, as is the shadow, but the axis of Earth’s rotation is not quite perpendicular to the direction of motion of the shadow, and furthermore, the Earth is a sphere.  The result is much more complex than just a round shadow moving … Continue reading

The Great KENTUCKY Eclipse of August 21, 2017: Measuring the Moon’s Distance
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With the eclipse coming on Monday, and with Vatican Observatory Director and boss blogger for The Catholic Astronomer Br. Guy being in Hopkinsville, Kentucky for the eclipse, you can bet you will see a lot of eclipse posts from The Catholic Astronomer’s Kentucky blogger!  (Click here for Monday’s post.) Here’s something you probably don’t think of when you think of eclipses: measuring the distance to the moon.  But you can use an eclipse to measure the distance to the moon.  You just need observers in two different places. Imagine one observer located in Louisville, where the maximum coverage during the eclipse will look like the image at below left, and a second observer located on the edge of the zone of totality, where the moon just covers the sun.  One such place in Kentucky is Morgantown.  Why is the position of the moon against the sun shifted slightly between the two locations?  Because of the difference in viewing position between … Continue reading

In the Sky This Week – August 15, 2017
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Venus is a bit lower and Orion a bit higher in the eastern morning sky. Venus orbits closer to the Sun than Earth, and is racing ahead-of and away-from the Earth; the planet will vanish from view in mid-November as the Sun comes between it and the Earth. The waning crescent Moon appears thinner and closer to the horizon each morning in the eastern sky. Note: I used Stellarium’s new “Astronomical calculations” feature to generate the ephemeris for this image – I expect you’ll be seeing more of this. The Moon be in conjunction with the star Aldebaran on the Aug. 16th, appearing VERY close to each other, VERY early in the morning. Aldebaran is a orange giant star about 44 times the size of the Sun, located about 65 light years away. Aldebaran is positioned close to the ecliptic plane, and is frequently occulted by the Moon… just not this month. Jupiter is visible only for a short time … Continue reading

21 Precious Perseids viewing pleasure
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My observing location for the 2017 Perseids was flanked toward the east by a large stony hill. Towards the west  the Atlantic Ocean and to both the south and north by fields of sheep. All week the forecast was less than favourable. It was a treat to have a relatively clear sky. Between local time 22:40 ( 21:40UT) and 23:35 ( 22:35UT) I observed 19 beautiful Perseids. Two white ones to start then a stunning blue mag 3 which spanned the width of Ursa Major. The vast majority were white with the occasional dim red Perseid zipping in from the direction of Perseus. Several of the white variety matched magnitudes of 2 + similar in brightness to many ISS passes. Some of them entered directly overhead, they spurted and spluttered their smoky trails just in case they were not noticed. On this occasion, I did not create a drawing, but simply enjoyed watching the show. The Milky way became increasingly … Continue reading

In the Sky This Week – August 8, 2017
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Venus is a bit lower in the eastern predawn sky, and Orion is fully visible now before sunrise. The waxing gibbous Moon, just days after full,  rises in the east with the sunset, and sets in the west with at dawn. Jupiter is low in the western sky, and visible for only a short time. Saturn is high in the southern sky after sunset, and sets about 2:00 AM. The Perseid Meteor shower peaks the evening of August 11-12th; the Moon will be at Third-Quarter on August 14th. Apps used for this post: Stellarium: a free open source planetarium app for PC/MAC/Linux. NASA Eyes on the Solar System: an immersive 3D solar system and space mission app – free for the PC /MAC. Also in In the Sky This Week Weekly post on what you can see in the sky. In the Sky This Week – June 22, 2017 In the Sky This Week – June 27, 2017 In the Sky This … Continue reading

Perseid Meteor Shower 2017: Aug. 11-12
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The Perseid meteor shower is a very popular annual event, with Perseid parties being held around the globe each year. Best seen from the northern hemisphere, the meteors will appear to radiate from a point in the constellation Perseus – between the “W” of the constellation Cassiopeia, and the bright star Capella (see image above). Every year I see posts about this year’s shower being the “shower of the century” or it will be the “brightest shower in the recorded human history!” I’m not so sure about that this year… although the Perseids typically puts on a pretty good show at about 100 per hour, the waning gibbous Moon will be bright, and just to the east of the radiant; this will obscure many of the dimmer meteors. Peak: August 11-12 Active from: July 13th to August 26th Radiant: 03:12 +57.6° (see image above) Hourly Rate: 100 Velocity: 37 miles/sec (swift – 60km/sec) Parent Object: 109P/Swift-Tuttle Source: American Meteor Society … Continue reading

In the Sky This Week – August 1, 2017
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Venus is still high in the eastern morning sky; the constellation Orion appears a bit higher each morning. The southern sky is filled with objects this week: the waxing gibbous Moon accompanies Jupiter and Saturn for several days. The Moon will appear very close to Saturn on the evening on August 2nd. The constellation Cetus appears in the predawn sky to the southeast. Cetus is depicted as a sea monster in Greek mythology, but is often referred to as “the whale” today. I know several astronomers who had a copy of H.A. Rey’s “The Stars: A New Way to See Them” when they were young – I still have my copy! I was overjoyed to see that Stellarium has a starlore set depicting constellations as drawn by H.A. Rey in his book. The constellation Cetus in Stellarium as drawn by H.A. Rey in his book “The Stars: A New Way to See Them.” The sky overhead – Aug 1, 2017 … Continue reading

Get the Moon in your head – Learn from Galileo and Apollo 11
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          Learn from  Galileo – 1610 ‘At conjunction the moon occupies a position between the sun and the earth; it is then illuminated by the sun’s rays on the side which is turned away from the earth. The other hemisphere, which faces the earth, is covered with darkness; hence the moon does not illuminate the surface of the earth at all. Next departing gradually from the sun, the moon comes to be lighted partly upon the side it turns toward us, and its whitish horns, still very thin, illuminate the earth with a faint light. The sun’s illumination of the moon increasing now as the moon approaches first quarter, a reflection of that light to the earth also increases. Soon the splendour on the moon extends to a semicircle, and our nights grow brighter; at length the entire visible face of the moon is irradiated by the suns resplendent rays, and at full moon the whole … Continue reading

This Post is Heretical! (and best read on long flight)
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This past Spring semester a student in my Astronomy 101 class at Jefferson Community & Technical College here in Louisville asked an interesting question: “Are Star Wars and Star Trek science fiction, or are they fantasy?”  Well, if science fiction requires scientific plausibility, then they are probably fantasy.  Why?  Because they rely on faster-than-light travel.  As best we can tell from the laws of physics, faster-than-light travel and communication are highly problematic from a theoretical perspective.  Moreover, even far slower travel has turned out to be problematic from a practical perspective.  Technology is not advancing in these key areas, and in one way we are significantly retreating.  Technology is endlessly hyped and marketed, so to say such things in today’s culture—or pop culture, if we are thinking of Star Wars and Star Trek—is to speak heresy.  But is it not true? Star Wars and Star Trek are built around an imagined advanced technology that allows for rapid travel and communication … Continue reading

What’s in the Sky July 25, 2017
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Venus is still bright in the eastern predawn sky, but a little bit lower each morning. The constellation Orion is rising with the dawn; a little more of the constellation visible each morning. A wafer-thin waxing crescent Moon will be visible for a short time after sunset in the west on July 25th. Jupiter is visible low in the southwestern sky, and will be a little lower in the sky each evening after sunset. Saturn is high in the southern sky, and is a great target for telescope observers. Jupiter will be a scant 3° South of the Moon after sunset on July 28th. The Moon will be at First Quarter on the evening of July 30th, surrounded by Jupiter and Saturn, and the Southern Delta Aquariids Meteor Shower peaks on July 29-30th; this would be a great evening to host an astronomy outreach event! Apps used for this post: Stellarium: a free open source planetarium app for PC/MAC/Linux. NASA … Continue reading