Text AdsWilderness Medicine Classes/Camp Broadstone
These faced paced, hands-on courses are essential for outdoor enthusiasts, trip leaders, and camp staff. •Wilderness First Responder March 7-15th •Wilderness First Aid April 18-19th •WFR Recertification May 1st-3rd ENROLLMENT IS LIMITED REGISTER TODAY!
campbroadstone.com/classes.phpBald Guy Brew

Online Store now open...
Free shipping on orders of five or more pounds!

Fresh Roasted, Fair Trade & Organic coffees.

828.297.JAVA

www.baldguybrew.comHiddenknoll Acupuncture Clinic: The Classical Art of Chinese Medicine
Edward D Elliott, Dipl.Ac., L.Ac. is offering Classical Chinese Medical services at two convenient locations: Boone NC: 181 Grandview Hts, & Jefferson, NC: 224 N. Main St at Crossroads Healing Center (Fridays only). Call (828) 278-0639
or click here for more details. Parker & Burgess Realty-Serving the High Country for Over 50 Years
Parker & Burgess Realty has been serving Ashe & surrounding counties for over 50 yrs. Licensed in NC & VA., we offer homes, vacation homes, lots, land, commercial, & certified appraisals. For more details call 336-246-6011
or click here to visit our website & review our listings.Build green. Save green.
Whatever its design, your new home can be beautiful and energy efficient. Using structural insulated panels will reduce your energy bills by 40-60 percent. Choose Highland Homes of NC, Inc. as your Energy Star home builder. Act now. Call Craig at 828-260-5815
or visit our website.

Life Outdoors
Preserving the High CountryBirdingThe Garden SlugTake it OutsideHigh Country WaterfallsBrenda's Bloomin WildflowersDan's Starry SkiesIdeas?Life Outdoors Setup
Make Text Larger Make Text Smaller Switch Fonts Email This Page Click Here For A Printable Version
Media Sponsors



Short Term Forecast - Mitchell (North Carolina)




Sponsorship Opportunity
Available



Dan's Starry Skies
by Dan Caton

Latest Update: December 31, 2008


IYA 2009 --the International Year of Astronomy
We start the new year with the beginning of the International Year of Astronomy 2009, a celebration of the discoveries made by Galileo 400 years ago when he was the first to turn the newly invented telescope to the sky. Throughout IYA 2009 we will feature as many of his discoveries as we can on this site. Since Galileo used modest telescopes, less powerful than the cheapest discount store models (or binoculars), you should be able to enjoy better views than he did of each object. We start this month with the phases of Venus, which reaches its greatest angle away from the sun during the evening twilight skies of mid-January. At that time it will form a 90-degree, right-angle with us and the Sun, and will be seen in a telescope to appear like a quarter Moon, with half the visible surface lit. This was one of the proofs that the ancient system of belief that the planets and Sun went around the Earth was incorrect. Since if that were the case, and since we observe Venus to never get farther than about 47 degrees from the Sun, its motion would be along an "epicycle," a circle that it would be traveling on which in itself moves about the Earth (the dotted circle in the first graphic below. In that case we would never see more than a thin crescent of phase for Venus, yet we actually see the full range from "new" to "full." So, Galileo showed that Venus and the Earth really travel around the Sun, allowing the full range of phases, as seen in the bottom figure. (Both figures are from "The Cosmos," a textbook by J. Pasachoff and Alex Filippenko, which I use in my astronomy course.) The additional figures below show Venus in Aquarius in the evening sky throughout the month, and an inset closeup of Venus at about the "quarter" phase as it will look mid-month. that picture, which shows more detail than possible in a ground-based telescope, is from the Hubble Space Telescope, courtesy of NASA.

The incorrect, geocentric model of the solar system, which would not allow all phases.


The correct, heliocentric model, which allows all phases of Venus.


Venus at mid-January evening sky, inset show quarter phase