Download Dark Skies Above Downeast Maine

Dark Skies Above Downeast Maine Celestial Events for the month of December The Eagle Hill institute would like to invite you to take a college astronomy course which will run from Saturday, January 12, 2013, to March 16, 2013. Class lectures will meet from 5 to 7 pm, and continue with the telescope classes from 8 to 10 pm. CLEAR SKIES! December 1 -­‐ Saturn, Venus, and Mercury will be visible in the morning sky for a little while. Watch as Venus moves away from Saturn and toward Mercury over the next 6 days. On the 7th or so, Venus will appear to make no further advance on Mercury as Mercury begins to apparently speed away from Venus toward the Sun. December 2 – Jupiter is at opposition tonight at 9 pm. It will be at its brightest in 2012 shining at a magnitude of -­‐2.8. It will appear telescopically to have an angular size of 48.5”. December 4 – Mercury will reach its greatest western elongation (highest elevation above the southeastern sky) (21 degrees) at 6 pm. The reason it is called a western elongation and seen in the early morning (eastern) sky, is because Mercury is at its farthest angular distance west of the Sun as seen from Earth. This therefore causes Mercury to rise before the Sun does, and therefore is seen in the eastern morning sky. December 6 – Last Quarter Moon occurs at 10:31 am. December 7 – Jupiter passes 4.7 degrees north of Aldebaran at 6 pm. December 9 – Spica will be about 1.4 degrees NNE of the 20% illuminated waning crescent moon at 6 am. December 10 – The Moon passes 4.7 degrees south of Saturn at 6 am. The Moon will be a 12% illuminated waning crescent. December 11 – The Moon will pass 2.4 degrees SSW of Venus at 6 am. The Moon will be a 5% illuminated waning crescent. Although not visible, the Moon passes 1.6 degrees south of Mercury at 8 pm. The Moon will be a 3% illuminated waning crescent. December 12 -­‐ The Moon is at perigee (221,876 miles from Earth), at 6:14 pm. December 13 – The Geminid Meteor Shower peaks today. View them from midnight to dawn. New Moon occurs at 3:42 am. No interference. December 15 – The Moon passes 9 degrees northeast of Mars at 5 pm. The Moon will be a 9% illuminated waxing crescent. December 17 – Venus is about 7.3 degrees west of Mercury at 6 am. For a small challenge, at 6 pm, Neptune will be about 5.8 degrees southeast of the Moon which will appear as a 27% illuminated waxing crescent. Neptune’s magnitude will be 7.92. To help you out a little in your search, Neptune will also be about 0.3 degrees southeast (position angle 147 degrees) of the 5.4 magnitude star called 38 Aquarii. Good Luck! December 18 – Ceres, the solar system’s largest asteroid, is viewable all night with a telescope. It reached its point of opposition to the Sun at 4 am. December 20 – First Quarter Moon occurs at 12:19 am. Uranus, (m= 5.82), will be about 4.6 degrees south (PA = 187 degrees) of the Moon. The Moon will be about 57% illuminated. December 21 – The Winter solstice occurs at 6:12 am. December 23 – Venus passes 5.7 degrees north of Antares, and 5.9 degrees NNE (PA 13 degrees) of the beautiful globular star cluster M4 at 6 am. M4’s m = 7.5. December 25 – The Moon is at apogee (252,337 miles from Earth), at 4:19 pm. The Moon passes 0.9 degrees SSE of Jupiter at 7 pm. December 28 – Full Moon occurs at 5:21 am. The Solar System (December 15, 2012) Mercury Venus Mars Ceres Jupiter Saturn Uranus Neptune Pluto Distance From 0.913 1.483 2.183 1.689 4.097 10.454 19.844 30.358 33.297 Earth (in AU)* Distance From Sun 0.335 0.722 1.393 2.671 5.058 9.788 20.059 29.991 32.350 (in AU)* Magnitude -­0.3 -­3.9 1.2 6.8 -­2.8 0.7 5.8 7.9 14.2 *AU stands for astronomical unit. 1 AU is equal to the average distance between the Sun and Earth which is about 92,955,634 miles. To convert AUs into miles, simply multiply the number of miles in 1 au to the au distance given. Miles = (AU distance x 92,955,634) The solar system’s minor objects During the month of December, there will be at least 1 minor body that will make a near approach to the Earth within a distance of 10 lunar distances. This closest approach will be from the asteroid known as 2009 BS5. It is scheduled to pass Earth on December 11 at an average distance of 2,017,137 miles. 2009 BS5 has a maximum size of about 20 meters in diameter, and will pass Earth at velocity of 5.69 km/s ( 12,729 mph). At this velocity and size, and assuming a density of 2,700 kg/m3; the asteroid would make a crater around 0.36 miles across. Thankfully, this asteroid will not hit us. Clear Skies!  The well-­‐known asteroid named 4179 Toutatis will pass Earth on December 12. It measures 5.4 kilometers in diameter. Toutatis will pass at a distance of 4,303,846 miles, and at a velocity of 11.91 km/s. If it were to pay us an unwanted visit, a crater measuring about 58.9 miles in diameter would occur. Math Challenge – This month, you need to calculate the velocity needed to escape The Sun’s gravity. The first person to send in the correct answer will receive an Eagle Hill Astronomy T-­‐Shirt. Good Luck! Don’t forget to include your name and other important information, or I won’t be able to send you your T-­‐Shirt. E-­‐mail [email protected] or call 546-­‐2821. Use: __________________ Vesc. = √(2 𝑮𝑴/𝑹) Where: V = Escape Velocity (m/s) G = The Gravitational Constant of the Universe = 6.67259E-­‐11 N.m2/kg2 M = Mass of the Sun (kg) = 1.989E30 kg R = Radius of the Sun (meters) = 696,007,317 meters V = ___________________________ m/s x 2.237 = ________________________________ mph Eagle Hill Institute Astronomy Survey: www.eaglehill.us/astronomy Eagle Hill Institute, 59 Eagle Hill Rd, PO Box 9, Steuben, ME 04680 For questions, please contact Ralph Battaline at 207-­546-­2821 x #212, or [email protected]