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

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

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

What’s in the Sky July 18, 2017
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Venus continues to dominate the morning sky in the east, but appears slightly lower in the sky each morning as it pulls ahead of us in its orbit. The waning crescent Moon will appear near Venus the the star Aldebaran on the mornings of July 19th and 20th. The New Moon will be on the 23rd. Jupiter and Saturn appear in the south-southwestern sky after sunset; Jupiter will appear slightly lower in the western sky each day as the Earth pulls ahead of Jupiter in its orbit. The constellations Pegasus and Andromeda appear low in the northeast sky after sunset; the wispy cloud of M31, the Andromeda galaxy, makes a good target for telescope observers. M31 is the nearest major galaxy to the Milky Way. It is 2.5 million light years distant, and heading straight at us; in a little over 4 billion years, it will collide with the Milky way, and the two galaxies will merge into a large … Continue reading

In the Sky This Week – July 11, 2017
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Venus continues to be the “morning star” in the east, and will appear very close to the red giant star Aldebaran – the “eye of the bull” in the constellation Taurus. On the 11th, Venus will be 3◦ north of Aldebaran, over the course of the week, Venus’ day to day change in position relative to Aldebaran will be very noticeable. In the west, bright stars Vega and Altair are the last to fade in the oncoming dawn. On the 11th, a waning gibbous Moon will be rise in the east before midnight, and set in the west around 9:00 AM. On the 18th, a waning crescent Moon will rise shortly after 2:00 AM, and be visible until it is lost in the glare of the rising sun after 6:00 AM. The Moon will be at third quarter on the 16th, and will be visible from about 1:00 AM – 1:00 PM.* Jupiter and Saturn are visible in the southern sky … Continue reading

In the Sky This Week – July 4, 2017
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Venus is the bright morning star in the eastern sky, attended by the Pleiades star cluster, and the bright star Capella to the northeast. The southern sky is adorned with several jewels this week: the Moon appears high in the southern sky before sunset as a waxing gibbous – a few days past first quarter. Jupiter and Saturn are both visible, as are the bright stars Antares and Spica. The full Moon will be on July 9th. The bright star Altair (featured in the classic SF film Forbidden Planet) rises in the east followed by the constellation Sagittarius to the southeast. Sagittarius is recognizable by “The Teapot” asterism low on the horizon. Sagittarius has several interesting deep sky objects to observe using telescopes; something cool you can do with the public during nighttime observing sessions is point to the Teapot’s spout and say “that’s where center of our Milky Way galaxy is!” Before dawn, the constellation Hercules sets in the west, and “The … Continue reading

In the Sky This Week – June 27, 2017
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Venus remains high in the eastern morning sky, the Pleiades star cluster appears between Venus and the star Capella. The Moon is a waxing crescent, appearing in the west after sunset. Jupiter is high in the southwest, and Saturn is low in the southeast sky after sunset. There will be a conjunction of the Moon, Jupiter and the star Spica on the evenings of June 30th and July 1st. Here is the current positions of the planets in the solar system: 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 Week – July 4, 2017 In the Sky This Week – July 11, 2017 What’s in the Sky July 18, 2017 What’s in the Sky July 25, 2017 In the Sky This Week – August 1, 2017 In the Sky This … Continue reading

Eratosthenes Drawing Drama plus an Experiment opportunity for schools all over the planet
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On that cold evening back in 2007 Eratosthenes looked powerful in its position emerging into the suns warm rays. Rupes Recta was also inviting and Plato almost called me again. Even drenched in sunlight Plato’s steel grey floor carried those unmistakable flame shaped shadows. Eratosthenes is a truly dramatic crater, a sweeping mountain chain whips away from it in a visual series, of broken, deep shadows. Montes Appeninus is cut and chopped first by Mons Wolf, and then by Mons Ampere. Next in line, Christian Huygens name is lent to Mons Huygens named in honour of the discoverer of Saturn’s largest moon Titan . This high mountain (164,000ft) is a billion miles away from those primal methane or ethane seas discovered by the Cassini Huygens mission on one of its routine flybys. Mons Bradley and Mons Hadley cradle the Apollo 15 lunar landing area from 1971. A mission that put wheels on the moon for the first time. This wonderfully … Continue reading

Across the Universe: The Boundaries of the Unknown
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This column first ran in The Tablet in March 2014 Isaac Newton thought that planetary orbits in our solar system were kept stable by God’s direct intervention; they were proof to him that God existed. A hundred years later, the great French mathematician and skeptic Pierre-Simon Laplace described his new orbital theory to Napoleon and supposedly quipped of God’s role, “I have no need for that hypothesis.” In fact, it is bad theology to reduce God to merely a gap-filling hypothesis. Only recently, however, have we learned that, actually, planetary motions may sometimes not be so stable after all. One of the pioneers of studying chaos theory in celestial dynamics is Jack Wisdom, an MIT professor (and MacArthur “genius”) who is visiting the Vatican Observatory this month. He’s working now on modeling the complex interaction between the Moon’s orbit and spin with the spin and orbit of the Earth. It’s all tied to the larger issue of the origin of … Continue reading

It was Jupiter by the Moon this Morning
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My wife called me this morning – her students were asking “what planet was by the Moon this morning?” There was frost on the ground (and cars), the air was very crisp, and apparently there was a lot of earthshine on the Moon. Jupiter was 1.4° south of the Moon in this morning’s sky. Even though the Moon was just a thin waning crescent, the students said it was very bright. Good on my wife’s students for witnessing this conjunction! … Continue reading

Across the Universe: A Damp Kaboom
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This column first appeared in The Tablet in October 2009 “Where’s the kaboom?” asked my friend, imitating the whiny voice of the cartoon character Marvin the Martian. “There was supposed to be a Moon-shattering kaboom!” We were watching live television coverage of NASA’s LCROSS lunar orbiter impacting into a dark crater on the Moon. The idea was that water ice might be hidden in the shadows of craters like this one, set in a region of the Moon’s south pole where sunshine never reaches. Water vapor from all the comets that have hit the Moon over the last four billion years might be trapped and frozen there. By slamming a rocket into those shadows, a giant plume of rock and ice would be lifted out of the shadows and into the view of the nearby spacecraft, and telescopes on Earth. Or so proclaimed the hyperactive NASA press office. In fact, at the impact, only a faint infrared blip was visible in the spacecraft images. … Continue reading