In the Sky this Week- October 17, 2017
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A wafer-thin waning crescent Moon is very close to Mars before sunrise on October 17th; there was earthshine from my location – morning drivers heading east got a real treat! The distance between Venus and Mars in the morning sky continues to grow; Venus getting lower, and Mars getting higher each day. Venus will disappear from the morning sky in Mid November. Saturn is still a good observing target after dusk in the southwestern sky, but it is getting a lit lower in the sky each day. A wafer-thin waxing crescent Moon will accompany Saturn on October 23rd. The Orionids Meteor Shower peak will occur on October 21-22; best times to view the shower are after midnight, and before dawn on October 22nd. For a second week there are no sunspots visible from Earth, but the lingering coronal hole in the Sun’s northern region has gotten its own article and video at the Solar Dynamics Observatory (SDO) website: The Inner Solar System … Continue reading

In the Sky this Week- October 10, 2017
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The waning gibbous Moon is high in the southern sky before dawn; The Moon will be at third quarter on the 12th, traveling eastward and a bit lower each morning, it will be a waning crescent from the 13th through the 19th. The Moon will occult the star Regulus before sunrise on Oct. 15th. For a map and timing of the occultation for your location, click this link. Venus and Mars continue to appear close together, low in the eastern predawn sky. The Moon will appear very close to Mars on the morning of Oct. 17th. On October 14th, asteroid 2012 TC14 will pass by the Earth at 0.13 Lunar Distances – that’s WELL inside Earth’s geosynchronous satellite ring; the asteroid is estimated to be 8-26 meters in diameter. Earth’s gravity will bend the orbit of the asteroid as it passes by. There are currently no sunspots visible from Earth, but the coronal hole that has been hanging around for … Continue reading

In the Sky this Week- September 26, 2017
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Winter stars are getting higher and higher in the predawn skies; if you are an early-riser, the Orion Nebula is visible for several hours before dawn in the southern sky. Regulus, Venus and Mars aligned in the predawn sky on Sept. 26th. The waxing crescent Moon will be very close to Saturn after sunset on the 26th; the next few days will be excellent for telescope observing. The first quarter Moon will be on Sept. 27th; the Moon will still be fairly close to Saturn that evening. The Moon will almost be full by the beginning of next week; it should be a great observing target all week long. Venus and Mars will be very close to each other in the predawn on Oct. 2nd. The Double Cluster is high in the northeastern sky after sunset. The Double Cluster (NGC 869 and NGC 884) is two open star clusters which appear close together in the constellation Perseus. Both visible to … Continue reading

In the Sky this Week- September 19, 2017
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A veritable riot of conjunctions is happening all week in the eastern predawn skies; Venus is VERY close to the star Regulus, and Mercury and Mars continue to be low in the sky before sunrise. These conjunctions can also be seen from the southern hemisphere; note how the position of the planets differs from the northern hemisphere. Saturn continues to be a good observing target in the southern skies after sunset. The southern skies seen from Perth after sunset are something I’d REALLY like to see; visible are the two Magellanic Clouds, the Carina Nebula In the eastern sky seen from Perth at 1:00 AM on Sept. 18th we see a good example of the different orientation of constellations seen from the southern hemisphere. The Pleiades star cluster can be seen high in the eastern sky at 2:00 AM. The Pleiades open star cluster consists of approximately 3,000 stars, and is among the nearest star clusters to Earth; the cluster … Continue reading

In the Sky this Week – September 12, 2017
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Mercury is about as high as it’s going to get in the eastern predawn sky on the 12th, and will start getting lower each morning. Sirius is high in the sky, and the constellation Canis Major is now fully visible above the southeastern horizon before sunrise. Mercury and Mars will appear very close to each other in the eastern predawn sky on the 16th. Saturn continues to be a great observing target in the southern sky after sunset. The Moon will be in conjunction with the star Aldebaran on the morning of the 12th, and will appear between(ish) the stars Aldebaran and Betelgeuse on the 13th. The eastern predawn sky on the 18th should look pretty interesting: Mercury, Mars, a sliver of a waning crescent Moon, the star Regulus and Venus will all appear in a line. Sunspot AR2680 has rotated into view; this sunspot is about the same size as AR2673 was from last week – which ballooned out and blew off … Continue reading

In the Sky This Week – August 22, 2017
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Sirius, the “Dog Star,” accompanies Venus low in the eastern predawn sky. Jupiter sets shortly after dusk and will vanish from view entirely in a early September. Saturn is high in the southern sky, and with the planet’s northern hemisphere tilted towards us at about 26°, Saturn is just a spectacular observing target. The Moon, fresh from the eclipse, will be in conjunction with Jupiter in the west at dusk on August 24th and 25th. The Moon will be a waxing crescent in the west at dusk, growing larger each evening until it is at first quarter on August 28th; the later part of this week will be excellent nights for star parties. Sirius, the brightest star in Earth’s sky, is a binary star system about 8.6 light years away. Sirius A is a bright and hot main sequence star, with a faint white dwarf companion: Sirius B. Sirius A is class A0 star about twice the mass of the … 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

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

In the Sky This Week – 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

In the Sky This Week – 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