North Houston Astronomy Club North Star Newsletter September 2009 Volume IX No. 9 NHAC General Meeting August 28, 2009 Novice Program Advanced Program “September Skies: A Teapot Full of “Venus: A Clouded Mystery” Surprises” By: Mr. Bill Leach 6:30-7:15PM - CLA 221, The Cosmic Forum By: Mr. Bruce Pollard 6:30-7:15PM - CLA 225, Physics Lab Main Presentation Beginning at 7:30PM, in the building CLA Teaching Theater Featuring: NHAC news and announcements, “What's Up Doc?”, by Aaron Clevenson “Captain Comet” Update, by Don Pearce Our featured speaker: “Is A Surprise!” 1 NHAC North Star Newsletter September 2009 P a g e 2 Inside this issue: Upcoming Meeting Reminder 1 Table of Contents and Thank You 2 Members Marketplace 3 A Spot On Night for Observing Jupiter by Susan and Bruce Pollard 5 News and Tidbits 6 Mars Rover Update—Meteorite found on Mars 7 September Calendar 9 About NHAC 10 A Very special thank you to Paul Derrick for presenting the Novice program on “Learning the Night Sky by Regions” and for giving the Main presentation on “Our Expanding Universe”. 2 NHAC North Star Newsletter September 2009 P a g e 3 Members, Do you have any astronomical related goods or services to buy, sell, or barter? Well, this page has been created just for you! Please send your ad to me at [email protected] and I will put it in the next issue. ADVANTAGE Telescope Repair • Repair and upgrades for all makes • Custom painting • FOR SALE : Refurbished telescopes… all “supercharged” • Cleaning, collimation, and star testing • Fabrication • Machine work Call 713-569-7529 3 NHAC North Star Newsletter September 2009 P a g e 4 The Deadline for submissions for the next newsletter is September 13, 2009 Elected Officers President: Lorrie Patel Editor: Joe Wagner Membership Committee Chair- [email protected] [email protected] person: Stuart Davenport Vice President:: Bruce Pollard Webmaster: Ed Knapton [email protected] Vice presi- [email protected] Program Committee Chairper- son: Juan Carlos Reina [email protected] ALCOR: Aaron Clevenson [email protected] Secretary: Bill Leach [email protected] [email protected] Observation Committee Chair- Treasurer: George Marsden person: Dave Clark [email protected] [email protected] “ Two men look out through the same bars; one sees the mud and one the stars. Frederick Langbridge (1849—1923) Proud member of: 4 NHAC North Star Newsletter September 2009 P a g e 5 Observe - Learn - Share A Spot-On Night for Observing Jupiter By Susan and Bruce Pollard We (Bruce and Susan Pollard) went to the George Observatory on July 25 to help Jason McCollum, Bill and Linda Christian with the public viewing and then stayed late to have a look at the impact spot on Jupiter. The skies were cloudy early on so the public viewing was limited to a few stars between the clouds rolling through. We were cautiously optimistic about having a view of Jupiter later as clearing skies were predicted. We waited until about 1:30am and ventured out to the East Dome Telescope. The sky cleared and Jupiter with its new dark spot was very visible. Al- though the spot was reasonably clear, we tested different color filters to see if one made the impact spot most visible, but there was no improvement. In the research dome we looked through the 36 inch telescope but the best view of the impact site was through the 10 ½ inch refractor. It showed up quite well as a brown spot near the upper right section of the planet. As an added bonus Io was in transit across the face of Jupiter and could be seen as it crossed the edge of the planet. We owe Justin many thanks for his help in being able to spot this amazing sight. Europa moved behind the planet around 2am. In addition, to all the action taking place on Jupiter, it was a thrill to be one of a few people getting the chance to use these big tele- scopes. All in all it was an impressive night of viewing. We are looking for- ward to our next outing at the George! Susan and Bruce Pollard [email protected] 8/16/09 5 NHAC North Star Newsletter September 2009 P a g e 6 News and Tidbits Astronomy Day 2009 9th Annual Texas Gulf Coast Astronomy Meeting: Friday, October 23, 2009. Astronomy Day 2009: Saturday, October 24, 2009 at The George Observatory. http://www.astronomyday.org/ Upcoming Star Parties The Eldorado Star Party will be held Oct.12-18, 2009 at the X Bar Ranch Nature Retreat in Eldorado, Texas. For more information and registration go to their website at: http://www.texasstarparty.org/eldorado.html The Okie-Tex Star Party will be held September 12-20, 2009 at Camp Billy Joe in the Black Mesa Area of Oklahoma. For information and registration go to their website at: http://www.okie-tex.com/index.php Administaff Observatory The next public event is Friday September 11 starting at 7:30 and other future events are listed at the observatories website: www.humble.k12.tx.us/observatory.htm Parking : Please park in the front parking lot at Jack Fields Elementary. The observa- tory is a short walk back to the left of the school; just look for the red lights. 6 NHAC North Star Newsletter September 2009 P a g e 7 Meteorite Found on Mars Yields Clues about Planet's Past This view of a rock called "Block Island," the largest meteorite yet found on Mars, comes from the panoramic camera (Pancam) on NASA's Mars Exploration Rover Opportunity PASADENA, Calif. -- NASA's Mars Rover Opportunity is investigating a metallic meteorite the size of a large watermelon that is providing researchers more details about the Red Planet's environ- mental history. The rock, dubbed "Block Island," is larger than any other known meteorite on Mars. Scientists cal- culate it is too massive to have hit the ground without disintegrating unless Mars had a much thicker atmosphere than it has now when the rock fell. Atmosphere slows the descent of meteorites. Addi- tional studies also may provide clues about how weathering has affected the rock since it fell. Two weeks ago, Opportunity had driven approximately 600 feet past the rock in a Mars region called Meridiani Planum. An image the rover had taken a few days earlier and stored was then transmitted back to Earth. The image showed the rock is approximately 2 feet in length, half that in height, and has a bluish tint that distinguishes it from other rocks in the area. The rover team decided to have Opportunity backtrack for a closer look, eventually touching Block Island with its robotic arm. 7 NHAC North Star Newsletter September 2009 P a g e 8 Meteorite Found on Mars Yields Clues about Planet's Past Continued "There's no question that it is an iron-nickel meteorite," said Ralf Gellert of the University of Guelph in Ontario, Can- ada. Gellert is the lead scientist for the rover's alpha particle X-ray spectrometer, an instrument on the arm used for identifying key elements in an object. "We already investigated several spots that showed elemental variations on the sur- face. This might tell us if and how the metal was altered since it landed on Mars." The microscopic imager on the arm revealed a distinctive triangular pattern in Block Island's surface texture, matching a pattern common in iron-nickel meteorites found on Earth. "Normally this pattern is exposed when the meteorite is cut, polished and etched with acid," said Tim McCoy, a rover team member from the Smithsonian Institution in Washington. "Sometimes it shows up on the surface of meteorites that have been eroded by windblown sand in deserts, and that appears to be what we see with Block Island." Opportunity found a smaller iron-nickel meteorite, called "Heat Shield Rock," in late 2004. At about a half ton or more, Block Island is roughly 10 times as massive as Heat Shield Rock and several times too big to have landed intact without more braking than today's Martian atmosphere could provide. "Consideration of existing model results indicates a meteorite this size requires a thicker atmosphere," said rover team member Matt Golombek of NASA's Jet Propulsion Laboratory in Pasadena, Calif. "Either Mars has hidden reserves of carbon-dioxide ice that can supply large amounts of carbon-dioxide gas into the atmosphere during warm periods of more recent climate cycles, or Block Island fell billions of years ago." Spectrometer observations have already identified variations in the composition of Block Island at different points on the rock's surface. The differences could result from interaction of the rock with the Martian environment, where the metal becomes more rusted from weathering with longer exposures to water vapor or liquid. "We have lots of iron-nickel meteorites on Earth. We're using this meteorite as a way to study Mars," said Albert Yen, a rover team member at JPL. "Before we drive away from Block Island, we intend to examine more targets on this rock where the images show variations in color and texture. We're looking to see how extensively the rock surface has been altered, which helps us understand the history of the Martian climate since it fell." When the investigation of Block Island concludes, the team plans to resume driving Opportunity on a route from Victoria Crater, which the rover explored for two years, toward the much larger Endeavour Crater. Opportunity has covered about one-fifth of the 12-mile route plotted for safe travel to Endeavour since the rover left Victoria nearly a year ago.