Words of Wisdom:

"If at first you don't succeed, try reading the directions!"

The Astronomy Club of Tulsa Meeting

WHEN:

Friday January 29, 1999 at 7:30 P.M.

WHERE:

February 26, March 26, April 30

This meeting will be our annual "Show & Tell" where club members have the opportunity to share all the neat gadgets and paraphernalia they either got for Christmas or have owned for some time and would like to share. Please consider bringing any or all of your "stuff" to show off. There is a ramp to help transport larger equipment into the same entrance mentioned above. Please contact me if you need special help or arrangements.

Chris Brown gave an excellent presentation using slides on Edwin Hubble: his biography, what his discoveries meant to astronomy, and the telescope he used. Thanks Chris!

Please read through the following list of committees and consider where you would like to help. If every club member could help serve in some capacity, even for a limited time period, it would help us accomplish so much more. I'll have a sign-up sheet for all the committees at the January meeting so you can get involved. Even if you have told me verbally an area you are interested in, please plan to sign up. If you should miss the January meeting, please call me and let me know.

1.Contact Committee - make phone calls for volunteers to help with events, reservations for restaurants, or any other contacts needed

2.New Members Pack Committee - develop new members pack

3.Security Committee - locate and install new locks at RMCC observatory

4.Multimedia (Public Relations) Committee - put together publications, brochures, or multimedia presentations about club and its activities

5.Grant Writing Committee - obtain financial backing and resources for club's "wish list"

6.Fund-raiser Committee - create ways to raise income for club

7.Historical Committee - compile the history of ACT in a document or book format

8.Education Committee - develop educational methods and materials to inform club members and the public

9.Dark Sky Committee - locate and appraise possible dark-sky sites for telescopic viewing

10.Membership Roster Committee - put together a professional quality listing of members booklet

The following list shows the meeting dates for 1999. Note that every meeting is on the last Friday of the month except in November and December, where the holidays conflict:

January 29, February 26, March 26, April 30, May 28, June 25, July 30, August 27, September 24, October 29, November 19, December 17

Please make every attempt possible to attend the January meeting. I have an important announcement to make concerning the future of our club.

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By Don Cole

Moving on outward in our "Journey to the Stars" we next come to mighty Jupiter.

Jupiter, named after the king of the Roman Gods, reigns supreme among the nine planets of our solar system, rivaling the Sun in its grandeur. Giant Jupiter contains two-thirds of the planetary mass of the solar system. In composition it resembles a small star. Its interior pressure may reach 100 million times the surface pressure on Earth. Jupiter's magnetic field is immense, even in proportion to the size of the planet, stretching millions of miles into the solar system. If the magnetic field were visible, it would rival the apparent size of our Moon. Electrical activity in Jupiter is so strong that it pours billions of watts into Earth's own magnetic field every day. No planet has greater influence on its neighbors.

Endowed with 16 known moons, a ring system, and an immense, complex atmosphere, Jupiter is the innermost of the 4 giant planets (the others are Saturn, Uranus, and Neptune), and clearly the most dynamic. The four largest of Jupiter's moons was discovered in 1610 by Galileo. They were subsequently named after mythological paramours of Jupiter (or Zeus in the Greek pantheon): Io, Europa, Ganymede, and Callisto. This tradition has been followed in the naming of the other moons. Modern observations have shown that the mean densities of the largest moons follow the trend apparent in the solar system itself. Io and Europa, close to Jupiter, are dense and rocky like the inner planets. Ganymede and Callisto, at greater distances, are composed largely of water ice and have low densities. During the formation of both planets and satellites, proximity to the central body (the sun or Jupiter) evidently prevented the more volatile substances from condensing. Its atmosphere bristles with lightning and swirls with huge storm systems including the Great Red Spot, a storm that has persisted for at least 100---and perhaps as long as 300---years. With its dynamism, huge energy output, and entourage of satellites, Jupiter is in many ways like a small sun, and the Jovian system resembles a miniature solar system. Although Jupiter is a stellar composition----most of its mass is hydrogen and helium---it does not burn like the Sun. Models of star formation suggest that Jupiter's mass is only about one-eightieth of the mass needed for ignition, which occurs due to heating from internal gravitational collapse. Jupiter's smaller size leaves its center too cool to ignite, sustaining instead internal masses of liquefied gas.

Jupiter holds clues to many of the mysteries of the early solar system. About 4.5 billion years ago, when the solar system formed out of a swirling mass of gases and dust called the solar nebula, Jupiter's core probably began as a solid mass of ice and rock about 15 times the bulk of Earth. The ice content of Jupiter's mass was high because it formed in the colder outer region of the solar system, where the nebula contained a lot of ice particles, principally water and methane. Probably because icy masses can adhere and compress into a single large body faster than plain rock can, the outer planets formed their cores before the rocky inner planets did. The gravity of the large icy cores of Jupiter and Saturn attracted most of the light hydrogen and helium gas in the nebula, and it is these gasses that we find dominating their atmospheres today. Jupiter, the innermost of the icy giants, "grew" the largest atmosphere. In fact, the face of Jupiter that we see is really just the top of its atmosphere. What goes on inside is even more intriguing.

Jupiter's massive atmosphere creates tremendous pressures as you move closer to the center of the planet. The substances inside the atmosphere are subject to extreme conditions, leading to exotic chemistry. For example, scientists have reason to believe that the inner layers of hydrogen in Jupiter's atmosphere, under the pressure of the atmosphere above, may have formed into a planet- encircling layer of what is called liquid metallic hydrogen. Not exactly an ocean, not exactly atmosphere, this layer of hydrogen would have properties that stretch our understanding of chemistry. Instead of the simple, free-moving and loosely bonded behavior of gaseous hydrogen, liquid metallic hydrogen is a strange matrix capable of conducting huge electrical currents. The persistent radio noise and improbably strong magnetic field of Jupiter could both emanate from this layer of metallic liquid. Some scientists theorize that beneath this layer there is no solid mass at the center of Jupiter, but that the unique temperature and pressure conditions sustain a core whose density is more like liquid or slush.

Farther from the planet's core, in what we can more certainly call the atmosphere, we see gases behaving in a more familiar manner, moving in general planetary circulations driven primarily by the rotation of the planet. Jupiter is believed to have three cloud layers in its atmosphere. At the top are clouds of ammonia ice; beneath that ammonium-hydrogen sulfide crystals; and in the lowest layer, water ice and perhaps liquid water. Jupiter is noteworthy for its turbulent cloudtops, and its long- standing storm, the Great Red Spot. The origins of these colorful features are uncertain, but scientists believe that they are caused by plumes of warmer gases that rise up from deep in the planet's interior. The plumes' colors are probably caused by their chemical content. Although the amount of carbon, for example, in the Jovian atmosphere is very small, carbon readily combines with hydrogen and trace amounts of oxygen to form a variety of gases such as carbon monoxide, methane, and other organic compounds. The orange and brown colors in Jupiter's clouds may be attributable to the presence of organic compounds, or sulfur and phosphorus.

Missions of Discovery

Jupiter is one of the planets visible to the naked eye, and its path through the night sky has been traced for thousands of years. In 1610, the Italian astronomer Galileo Galilei discovered four large moons -- Io, Europa, Ganymede, and Callisto (known as the Galilean satellites) -- orbiting Jupiter. This was one of the earliest astronomical discoveries made with a telescope. It fueled the controversial argument of the time that the Sun and not the Earth was the center of the solar system. In the centuries since then, as telescopes improved, Jupiter because known primarily for its size and the Great Red Spot, which was imagined to be an island in a Jovian sea. As Earth-based astronomy continued to improve, we came to realize that the few fuzzy "surface" features we could see were constantly changing in position, size, and color, suggesting that they were atmospheric phenomena. With the advent of radio astronomy, we discovered that Jupiter is a source of strong radio- frequency noise, suggesting electrical activity. Our fascination with Jupiter increased.

In March 1972, NASA launched the Pioneer 10 spacecraft to observe the asteroid belt and Jupiter. Arriving at Jupiter in December 1973, Pioneer 10 revealed Jupiter's intense radiation output, its tremendous magnetic field, and the probability of a liquid interior. One year later, Pioneer 10's sister spacecraft, Pioneer 11, flew by Jupiter on its way to Saturn, and provided even more detailed imagery and measurements, including our first close-up look at the giant planet's polar regions. Then, in August and September 1977, NASA launched the two Voyager spacecraft to the outer solar system. The Voyagers' 1979 encounters with Jupiter provided us with startling, beautiful imagery of the king of the planets, revealing thousands of features never before seen. Swirling multicolored turbulence surrounded the Great Red Spot. Rising plumes and spinning eddies formed and dissipated, suggesting a strong source of heat bubbling up from within the planet.

The Voyager imagery, with its exposure of so many small details, told us that Jovian dynamics were much more complex than previously imagined. Yet many of the features resemble effects we know of in our own and other planetary atmospheres, magnified by the enormity and extremity of the Jovian environment. In studying Jupiter we can learn more about atmospheric effects and interactions that are subtle on Earth, such as magnetosphere-atmosphere interactions. Subsequent missions to the giant planet will help us improve models of atmospheric dynamics, and will help us understand the chemistry and behavior of Earth's own relatively thin, but very precious, atmosphere.

What is an Oxidizer? A complex mix of several compounds or chemicals that inherently contain enough oxygen suspension so as to support a combustible mixture when no other external oxygen exists. Because all combustible rocket propellants contain both fuel and an oxidizer, a rocket may develop thrust independent of its surroundings, unlike other types of jet engines that utilize oxygen from the atmosphere to burn fuel carried aboard . A rocket engine, therefore, is self-contained and must carry an Oxidizer onboard and is the only type of device suitable for flight propulsion in outer space.

Question : Of the complete STS stack that is launched, are any of the components reusable? If so, which ones? and how are they recovered for reuse?

So until next month Dark Skies and Steady Seeing to You ...

Reference Material :: "Astronomy, A self-teaching guide." by Dinah L. Moche (4th ed.) "Guide to the Stars" by Leslie Peltier. " Astronomy, For the Earth to the Universe" by Jay M. Pasachoff (3rd ed.)

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By Rusty Fletcher

This month I'd like to recommend a great web site that provides some very good articles about astronomy and a host of astronomical links. The site contains information about recent astronomical discoveries, theories, and events. Their is also a list of links to other web sites providing information about, Asteroids, Comets, Eclipses, The Hubble Space Telescope, Manned and Unmanned Space Missions, Observatories, Mars, Jupiter, NASA Resources, Online News, Societies and Groups, The International Space Station and much more. I think you will find this web site is defiantly worth your time to check out! The address is:

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For sale: Set of Telescope Making magazines. Missing six issues. Fair condition. $50.00. See at meeting. Evenings (918) 747-5634. Phil Davis.

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A good occultation of Aldebaran by the waxing gibbous Moon can be seen with binoculars or camcorders from most of North America on Tuesday night, January 26-27th. For the southern USA and Mexico, this will be the LAST nighttime occultation of Aldebaran of the current series; those areas will have to wait 14 years for another opportunity to see this star, the brightest other than the Sun that can be occulted, covered by the Moon again. So please try to make the most of this opportunity; pass on local information about the event to colleagues, friends, and relatives, especially those with camcorders, not just to fellow amateur astronomers, since this is an event that does not need a telescope. For observers in western Canada, most of the Midwest, and the Northwest, it will provide good practice for the even better Aldebaran occultation on Sunday evening, April 18.

Information about the occultation is given on pages 110 and 111 of the 1999 February issue of Sky and Telescope. West of the Appalachians, the disappearance can be seen easily with binoculars and possibly even with the naked eye, and recorded with camcorders of 12x or higher power (almost all camcorders now). Along populous parts of the East Coast, the event will occur only a few degrees above the western horizon, but even so, if the sky is clear and a location with an unobstructed view low in the west can be found, it is likely that the disappearance can be timed directly with camcorders of 20x or greater.

The IOTA Web site for most occultation information, and for the coordination efforts, is http://www.sky.net/~robinson/iotandx.htm

The club will meet the last Friday of each month except for November and December when a holiday will interfere with the last Friday. The November meeting will be on the 19th, and the December meeting will be on the 17th.

The dates are:

26 February

26 March

30 April

28 May

25 June

30 July

27 August

24 September

29 October

19 November

17 December