Mar 2018
Financials:
Feb. 1, 2018, beginning balance: $3018.31
Two Dues Renewals: +$40.00
Expense: Craft Supplies for Tulsa Central Library Astronomy Night: <$81.21>
Expense: OK Secretary of State for Charitable Organization Registration: <$15.00>
Feb 28, 2018, ending balance: $2962.10
Attendance:
19 people in attendance including 1 new member
Equipment update:
Update from Lashawn on picking up equipment from Steve Plank's family--
She has at least three of the Night Sky Network kits (out of 7, possibly more). She also has the BAS banner and one of the two projectors.
These various items are in "cases" and for now, Rick Bryant has them.
Update on getting the ten-inch Meade telescope, with various lenses, that is owned by the Club but that Jerry Koenig now has: Karen asked if anyone knew Jerry well enough to ask him about this. (Karen has tried, but no response to date.) Denise offered to try to contact him.
Star Party coordinator:
Karen has received no offers from any Club members to be Star Party coordinator. Denise offered to work on it, but if a couple others would also offer to help so the work could be shared. John, Craig, and Karen offered to help with this as time permits for them. (At the end of the meeting Bob Young also offered to help.) We still want to try to have one members-only star party per quarter, plus ad-hoc for the general public when there is something going on of special interest.
Update on March Tulsa City County Library Astronomy Night March 6:
Lashawn has all the craft supplies for 150 comet necklaces and 100 solar system hats; Denise has 160 handouts to go with the comet necklaces. John mentioned also bringing the Club's beginning astronomy handout; Denise said she has some of these and will bring to give to youth who are especially interested (since these cost $$ to print in color at Staples). Rick Buck and Evan Zorn will bring telescopes and Lashawn, Abby and Denise will do the crafts. John Land with the Tulsa club says they will supply 5-6 volunteers including several scopes.
Main presentation--Legacy of Cassini by Abby Bollenbach
Abby opened her presentation with several slides packed with facts summarizing the Cassini mission. The Secretary was unable to write all these down fast enough, but here is an excerpt from a summary from Wikipedia that gives the gist of what Abby presented in her opening slides:
The Cassini–Huygens mission, commonly called Cassini, was a collaboration between NASA, the European Space Agency (ESA), and the Italian Space Agency (ASI) to send a probe to study the planet Saturn and its system, including its rings and natural satellites. The Flagship-class robotic spacecraft comprised both NASA's Cassini probe and ESA's Huygens lander which landed on Saturn's largest moon, Titan. Cassini was the fourth space probe to visit Saturn and the first to enter its orbit. The craft was named after astronomers Giovanni Cassini and Christiaan Huygens.
Launched aboard a Titan IVB/Centaur on October 15, 1997, Cassini was active in space for nearly 20 years, with 13 years spent orbiting Saturn, studying the planet and its system after entering orbit on July 1, 2004.[8] The voyage to Saturn included flybys of Venus (April 1998 and July 1999), Earth (August 1999), the asteroid 2685 Masursky, and Jupiter (December 2000). Its mission ended on September 15, 2017, when Cassini's trajectory took it into Saturn's upper atmosphere and it burned up[9][10] in order to prevent any risk of contaminating Saturn's moons, which might have offered habitable environments to stowaway terrestrial microbes on the spacecraft. The mission is widely perceived to have been successful beyond expectation. Cassini-Huygens has been described by NASA's Planetary Science Division Director as a "mission of firsts", that has revolutionized human understanding of the Saturn system, including its moons and rings, and our understanding of where life might be found in the Solar System.
Cassini's original mission was planned to last for four years, from June 2004 to May 2008. The mission was extended for another two years until September 2010, branded the Cassini Equinox Mission. The mission was extended a second and final time with the Cassini Solstice Mission, lasting another seven years until September 15, 2017, on which date Cassini was de-orbited to burn up in Saturn's upper atmosphere.
The Huygens module traveled with Cassini until its separation from the probe on December 25, 2004; it was landed by parachute on Titan on January 14, 2005. It returned data to Earth for around 90 minutes, using the orbiter as a relay. This was the first landing ever accomplished in the outer Solar System and the first landing on a moon other than our own. At the end of its mission, the Cassini spacecraft executed the "Grand Finale" of its mission: a number of risky passes through the gaps between Saturn and Saturn's inner rings. The purpose of this phase was to maximize Cassini's scientific outcome before the spacecraft was disposed of. The atmospheric entry of Cassini ended the mission, but analyses of the returned data will continue for many years.
Christiaan Huygens (1629-1695) was the first to observe Saturn's largest moon, Titan.
Giovanni Cassini (1625-1712) was a mathematician, astronomer, and engineer who discovered four of Saturn's moons and observed the division of the rings of Saturn. (Galileo was the first to observe that Saturn has rings.)
Abby pointed out that Cassini's mission was not done serially--in other words, the planners didn't wait for one Cassini observation project to be finished before another was started. Otherwise, all the work that it did would have taken much longer. Nonetheless, the Cassini mission was in development for a decade.
2.5 million commands were executed by Cassini.
Plutonium (not with a nuclear reactor) was used to generate power.
The Huygens probe revealed that Titan's atmosphere has nitrogen but not xenon or krypton. Amino acids are present. Titan is the second largest moon in our solar system; it is larger than Mercury. It is 53% larger in diameter than the Moon and its core has several layers.
Scientists are intrigued by the possibility that the chemical compounds on Titan and in its atmosphere could be conducive to the development of life.
Abby then discussed one of the most interesting features of Saturn that were captured in images by Cassini in the north polar region: the hexagon jet stream. It is 20,000 miles across and has an “eye” 1250 miles wide. Images show lightning within the hexagon. It was first observed by two Voyager spacecraft in the early 1980s, but those craft were unable to capture an image of the hexagon in its entirety.
She also discussed the mega-storm that erupted on Saturn in late 2010. The storm was able to churn up water ice from great depths; this finding was derived from near-infrared measurements by Cassini. It was the first detection of water ice on Saturn; it originated from deep in Saturn’s atmosphere. Storms such as these occur on Saturn about once every 30 years, which is roughly once per Saturn year. A Saturn year is 29.5 Earth years; one “season” on Saturn lasts 7 of our years.)
She also discussed (and showed images) of the beautiful auroras from Saturn’s magnetosphere.
Abby also showed images of Saturn’s corrugated rings, which contain rocks from asteroids, comets or moons that can be as large as mountains!
She also discussed that Saturns rings are actually very thin vertically—they are only about 10 meters thick; the rings are 30 million times wider than they are thick! She showed images of the icy rings’ shadows.
Saturn has 53 known icy moons and nine “maybes”. She discussed the moon Enceladus’ ultra-bright appearance (the brightest world in our solar system). Cassini discovered that the fresh coating on its surface, as well as the icy material in Saturn’s E-ring, come from vents connected to a global subsurface saltwater ocean on Enceladus that might have hydrothermal vents. Geyser-like jets spew water vapor and ice particles from the underground ocean underneath Enceladus’ icy crust. Some of it falls back on to Enceladus’ surface and some escapes to become part of Saturn’s E-ring. Enceladus is not large—it is only about 310 miles wide.
Cassini made 22 deep dives between Saturn’s rings and cloud tops. It made its final dive onto Saturn on September 15, 2017; this was planned in order not to cause any damage to Saturns’ moons.
This description of Abby’s talk cannot do justice to the many fabulous images that were taken by the Cassini mission. Some of Cassini’s photography was guided directly by human intervention; others images were taken using pre-sent programming. All of the images were absolutely stunning. Saturn has always been one of the most beloved of our planets (besides our own) if not the most beloved beside our own, due to the photogenic rings. But these images taken by Cassini go far beyond what we see in a telescope. Some were taken using special filters to bring out detail and colors we might not otherwise see. But all were fabulous!