Stargazer #536

RayJones — Mon, 26 Jul 2010 18:44:30 -0400

STARGAZER #536 for July 24, 2010

Galileo and Saturn

In 1609 Galileo made his first perspicillum (see-through device) which we now call a telescope. It was initially used as a spyglass for seeing distant ships and other terrestrial objects.

In late in 1609 he first turned his device skyward and was astounded by views of the Moon, Jupiter, Venus and other heavenly bodies. But nothing confused him more than what he first saw 400 years ago this month. In announcing his discovery, he wrote, "I have observed the highest planet, triple-bodied," referring to Saturn which was then believed to be the most distant planet.

Elaborating his finding, he stated, "Saturn is not a single star, but is a composite of three, which almost touch each other, never change or move relative to each other, and are arranged in a row along the zodiac, the middle one being three times larger than the other two lateral ones...situated in this form - oOo."

It was a mystery Galileo never solved. His crude telescopes, inferior even to today's department store scopes, couldn't quite reveal what every school child now knows to be Saturn's rings. It wasn't until several years after Galileo's death that Christiaan Huygens, using a larger and improved telescope, solved Saturn's riddle.

To the naked eye and through most binoculars, Saturn looks like a bright star. But most of today's telescopes, even inexpensive ones, reveal what Galileo never saw clearly enough to understand.

Saturn is currently visible in our evening sky, so get out that scope tucked away in the closet, or call up a friend with a scope, or attend a local star party -- whatever it takes. Then for fun, pretend you're Galileo getting your first clear view of Saturn and its rings. Eureka!

Next Two Weeks. Avg. sunrise: 6:44 a.m.; avg. sunset: 8:25 p.m. Tomorrow's full Moon is called the Hay Moon and Thunder Moon. Tues. evening Mercury is a moonwidth to the lower left of the star Regulus near the western horizon at dusk, Mercury being the brighter. The morning of July 31 the Moon is above Jupiter high in the south, and that evening Mars is just to the lower left of brighter Saturn low in the west. Aug. 1 is Lammas, a cross-quarter day celebrating the middle of summer. The Moon is at 3rd quarter Aug. 2. The morning of Aug. 4 the Moon is above the Pleiades star cluster in the east.

Naked-eye Planets. (The Sun, Moon, and planets rise in the east and set in the west due to Earth's west-to-east rotation on its axis.) Evening: Venus is the brilliant "evening star" in the west. Mercury is just above the horizon two fist-widths (held at arm's length) to Venus' lower right. Saturn and Mars are a fist-width to Venus' upper left. Morning: Bright Jupiter, now rising before midnight, is high in the south by morning.

Mars Hoax. Regardless of what you might read on the Internet, come Aug. 27 Mars will not appear as large as the Moon. It never has and never will. Some variation of this preposterous Mars hoax has been circulating every summer since 2003 when Mars did come closer than usual. The only thing you need to remember Aug. 27 is the Stargazer's 70th birthday!

Star Party. The Central Texas Astronomical Society's free monthly star party is July 31 at the Lake Waco Wetlands beginning at 8 p.m. For directions see my Web site.

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Stargazer appears every other week in the Waco Tribune-Herald and other newspapers. Paul Derrick is an amateur astronomer who lives in Waco. Write him at 918 N. 30th St., Waco, TX 76707, call or fax at (254) 753-6920, or e-mail at paulderrickwaco@aol.com.

Copyright 2010 by Paul Derrick. Permission is granted for free electronic distribution as long as these paragraphs are included. Please obtain permission from the author for publication in any other form. To be added to (or removed from) the free e-mail distribution list, send your e-mail address (and name) to paulderrickwaco@aol.com.

* * See the Stargazer Web site at http://www.stargazerpaul.com.

Minutes 2007-06

Alan — Mon, 05 Jul 2010 17:53:21 -0400