October 2015 Sky Events The Planets this Month - page 2 Planet Highlights - page 10 Moon Phases - page 13 Orionid Meteor Shower Peaks Oct. 22 nd - page 14 Observe the Zodiacal Light - page 15 2 Bright Asteroids to View this Month - page 18 www.astroasheville.org
October 2015 Sky Events the Planets Saturn is the only bright planet that is visible in the early evening sky this month. You can find Saturn in the constellations Libra and Scorpius, low in the SW as darkness begins. Observe it early in the evening before it sets. It s too low in the sky this month to allow any crisp views of the planet s disk and ring system in a telescope. Uranus and Neptune are in fine viewing position this month. Find them with a telescope in the neighboring constellations of Pisces (for Uranus) and Aquarius (for Neptune).
October 2015 Sky Events the Planets Saturn and the crescent Moon in the SW at Dusk The view of Saturn and the Moon, looking SW about 30 minutes after sunset, along with the red giant star Antares in Scorpius Oct. 15 th Oct. 16 th
October 2015 Sky Events the Planets Uranus and Neptune remain in good viewing position this month. Find their small distant blue disks in a telescope during October. Neptune was at opposition on Aug. 31 st, and Uranus reaches opposition on October 11 th. Uranus Neptune Images and charts courtesy of Sky & Telescope
October 2015 Sky Events the Planets The Planets Uranus and Neptune with the Asteroid Vesta Uranus in Pisces Neptune in Aquarius Vesta in Cetus This chart shows the approximate positions of the 3 solar system objects on October 15, 2015 at 10:30 p.m. EDT. Vesta and Uranus are about 19 apart.
October 2015 Sky Events the Planets The real planetary action this month is in the dawn skies where Venus, Mars, Jupiter and Mercury will all align along the ecliptic forming some wonderful conjunctions. This means rising early, well before dawn, to observe this dance of the 4 planets low in the East, but it should prove most rewarding. Mercury reaches greatest elongation west (18 ) of the Sun on Oct. 16 th, and Venus reaches greatest elongation west (46 ) of the Sun on Oct. 26 th. Find Mercury low in the eastern dawn skies from Oct. 11 th to the 24 th using binoculars will help.
Venus, Mars & Jupiter line up along the ecliptic in the dawn skies this month with the constellation Leo in the background. The waning crescent Moon joins the trio from Oct. 8 th - 11 th. Astronomy Club of Asheville October 2015 Sky Events the Planets Find Venus, Mars & Jupiter Images courtesy of Sky & Telescope
October 2015 Sky Events the Planets Mercury joins 3 other planets in the Dawn Skies Mercury joins Venus, Mars and Jupiter along the ecliptic in the eastern dawn skies from Oct. 11 th - 24 th. On Oct. 11 th the waning crescent Moon is only 1½ from the planet Mercury. On Oct, 17 th Mars and Jupiter appear only ½ apart as the two trade dance positions! Images courtesy of Sky & Telescope
October 2015 Sky Events Venus, Jupiter and Mars are joined by Mercury in the eastern dawn skies On October 23 rd and 24 th find Venus, Jupiter and Mars within 5 degrees of each other along the ecliptic in the morning twilight. All 3 planets are in the constellation Leo this month. Oct. 23 rd & 24 th 45 minutes before sunrise Locate the speedy planet Mercury much lower on the ecliptic in the constellation Virgo. You may need binoculars to spot Mercury low toward the horizon.
October 2015 Planet Highlights Planet Avg. Distance from Earth Constellation(s) Avg. Diameter in arc seconds Avg. Magnitude Comments Page 1 of 3 Mercury 1.0 AUs Venus 0.6 AUs Mars 2.3 AUs Virgo 7.7-0.6 At greatest elongation west on October 16 th. Leo 28-4.6 At greatest elongation west on October 26 th. Leo 4.1 1.8 Find with Venus and Jupiter in the dawn skies
October 2015 Planet Highlights Planet Avg. Distance from Earth Constellation(s) Avg. Diameter in arc seconds Avg. Mag- nitude Comments Page 2 of 3 Jupiter 6.2 AUs Leo 32.2-1.8 Find with Venus and Mars in the dawn skies Saturn 10.7 AUs Libra & Scorpius 15.5 0.5 Low in the southwest as darkness begins Uranus 19 AUs Pisces 3.7 5.7 At opposition on October 11 th
October 2015 Planet Highlights Planet Avg. Distance from Earth Neptune 29 AUs Constellation(s) Avg. Diameter in arc seconds Avg. Mag- nitude Comments Page 3 of 3 Aquarius 2.3 7.8 Not far past its August 31 st opposition, and visible all night with a telescope
The Moon October 2015 Last Quarter 4 th 5:06 p.m. New Moon 12 th 8:06 p.m. First Quarter 20 th 4:31 p.m. Full Moon ** 27 th 8:05 a.m. ** The Hunter s Moon - defined as the full Moon that follows the Harvest Moon each year. Unless otherwise indicated, all times are EDT
October 2015 Highlight: Orionid Meteor Shower The Orionid Meteor shower reaches its peak this year before dawn on the morning of Thursday, October 22 nd. The Orionids are an annual meteor shower associated with Halley s Comet (comet dust!). They are named after their radiant point in the constellation Orion, where they appear to originate in the sky. Because this meteor shower peaks just past the First Quarter Moon this year, moonlight will not diminish the pre-dawn observing. Typically, Orionids appear at a rate of 10-20 per hour, moving swiftly across the sky.
October 2015 Highlight: Zodiacal Light October is the season to find the elusive zodiacal light in the early morning sky. But what is the zodiacal light? Zodiacal light is sunlight reflected from numerous dust grains located along the plane of the solar system the ecliptic or zodiac. These dust grains are left over from the formation of the solar system (a type of cosmic dust), and their supply is continuously fed by particles from comets and asteroid collisions. The ecliptic is nearly vertical to the horizon this month providing good viewing opportunities.
October 2015 Highlight: Zodiacal Light Zodiacal light is seen as a cone of light widest at the horizon. Look for it low in the east (with an unobstructed view) beginning about 2 hours before sunrise. Pick a very dark location far from artificial lights and without moonlight. In the fall (Sept. & Oct.), when it is visible in the morning sky, it is often called the false dawn. The viewing window closes about 80 minutes before sunrise. The best mornings to view the false dawn this month are: October 11 th to 25 th.
October 2015 Highlight: Zodiacal Light Zodiacal Light and the Milky Way
October 2015 Highlight 2 Bright Asteroids in the Night Sky this Month This month the largest asteroid and the brightest one 1 Ceres and 4 Vesta, respectively will be in good viewing position in night skies, presenting an excellent opportunity to view both of them in a modest telescope. You will need a finder s chart and/or a go-to telescope to locate these faint objects with certainty. Ceres will hover around magnitude 8.0 this month, while Vesta will be closer to magnitude 6.5. Despite its much smaller size, Vesta (Ceres is nearly twice as large) easily outshines dwarf planet Ceres because of its much higher albedo (reflectivity of sunlight). Vesta also happens to be approximately 112 million miles closer to Earth this month. Ceres is about 251 million miles distant this month, while Vesta is around 139 million miles away.
NASA s Dawn spacecraft has now encountered, orbited and imaged the two largest asteroids. Ceres Astronomy Club of Asheville October 2015 Highlight 2 Bright Asteroids in the Night Skies this Month Ceres orbits the Sun every 4.60 years while Vesta takes only 3.63 years. NASA s Dawn Spacecraft image of Ceres NASA s Dawn Spacecraft image of Vesta Vesta, Ceres and the Moon, for scale You will find the 1 st (Ceres) and 4 th (Vesta) asteroids discovered in the constellations Sagittarius and Cetus, respectively, this month.
Astronomy Club of Asheville October 2015 Highlight 2 Bright Asteroids in the Night Skies this Month Find some location charts for Ceres and Vesta at the Heaven- Above.com website. Ceres Chart link Vesta Chart link
October 2015 Highlight 2 Bright Asteroids in the Night Sky this Month Some History: Ceres was the first asteroid to be discovered, on 1 January 1801 by Giuseppe Piazzi in Palermo, Sicily, and at first it was considered to be a planet. Ceres is the ancient Roman goddess of agriculture, grain crops, fertility and motherly relationships. Vesta was discovered on 29 March 1807 by Heinrich Wilhelm Olbers. It was the 4 th asteroid to be discovered, and it too was originally considered to be a planet. Vesta is the ancient Roman virgin goddess of home and hearth. In 1851 astronomers demoted Ceres, Vesta and other asteroids from the ranks of the planets. Does this sound anything like the 2006 IAU (Int l Astronomical Union) demotion of Pluto?
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