In spite of mostly-cloudy weather during the day, we had between 30 and 40 guests attend our public star party last night (June 20) at Letha House Park.
By the time the program started at 9 PM, the sky had cleared to the west and we had a great view of Venus, Jupiter, and the crescent Moon in a group. The sky continued to clear from west to east and more objects became visible, including Saturn, Arcturus, Vega, etc. Jay Reynolds was able to get the Ring Nebula, Saturn, M13, and other objects with the big scopes in the observatory.
Jay and I were the only ones operating telescopes — Jay in the observatory and me outside showing the crescent Moon — so we got quite a workout. Many thanks to Carl Kudrna, and to new members Nora Mishney and Lester Morris who helped at my scope giving me a chance to talk with guests at our indoor display.
Saturday night, May 23, the Cuyahoga Astronomical Association (CAA) held our first Public Star Party for 2015. The event took place at the club’s observatory situated on the grounds of the Medina County Park System’s Letha House Park in Spencer, Ohio. Members of the public were generally enthusiastic, excitedly moving between telescopes. The sky was beautifully clear and allowed excellent views of the Moon, Jupiter, Saturn, Venus, the Hercules Star Cluster (M13), M81 & M82, and other astronomical wonders.
CAA President William Murmann wrote, “Thanks to everyone who attended and who brought scopes to help with the program!
“The park staff said we had about 50 guests join us, including families with children. We had clear skies all day, but some high, thin wispy stuff moved in during the evening, although we had good observing.
“It was nice to see to James Guilford, Steve Spears, Chris Christe, Chris Burke, Paul Leopold, Suzie Dills, Trevor Braun, Bob Wiersma, Jay Reynolds, Rich Rinehart, Bill & Carol Lee, Tim Campbell and Mary Ann, Steve & Gail Korylak, Rich & Nancy Whisler, Dave & Jan Heideloff, Carl Kudrna, Larry Smith — and new member Anita Kazarian, who joined us. Sorry if I missed anyone.
“Noteworthy for the evening–Steve Korylak spotted Comet Lovejoy with his scope.
“It was a nice program and a nice get together for members. Thanks again.”
Among the objects the public viewed in beautiful detail was Earth’s Moon. Early in the evening not only could observers see the brightly-lit portion of the Moon but also the Earth-lit shadowed portion of the disk. Adding to the scene was a beautiful speck of a star near the horn of the Moon: Acubens, a star in constellation Cancer.
On July 19, 2013 NASA’s Cassini spacecraft slipped into Saturn’s shadow and turned to image the planet, seven of its moons, its inner rings — and, in the background, our home planet, Earth. Wait, there’s more!
With the sun’s powerful and potentially damaging rays eclipsed by Saturn itself, Cassini’s onboard cameras were able to take advantage of this unique viewing geometry. They acquired a panoramic mosaic of the Saturn system that allows scientists to see details in the rings and throughout the system as they are backlit by the sun. This mosaic is special as it marks the third time our home planet was imaged from the outer solar system; the second time it was imaged by Cassini from Saturn’s orbit; and the first time ever that inhabitants of Earth were made aware in advance that their photo would be taken from such a great distance.
With both Cassini’s wide-angle and narrow-angle cameras aimed at Saturn, Cassini was able to capture 323 images in just over four hours. This final mosaic uses 141 of those wide-angle images. Images taken using the red, green and blue spectral filters of the wide-angle camera were combined and mosaicked together to create this natural-color view. An annotated version is shown here:
This image spans about 404,880 miles (651,591 kilometers) across.
The outermost ring shown here is Saturn’s E ring, the core of which is situated about 149,000 miles (240,000 kilometers) from Saturn. The geysers erupting from the south polar terrain of the moon Enceladus supply the fine icy particles that comprise the E ring; diffraction by sunlight gives the ring its blue color. Enceladus (313 miles, or 504 kilometers, across) and the extended plume formed by its jets are visible, embedded in the E ring on the left side of the mosaic.
At the 12 o’clock position and a bit inward from the E ring lies the barely discernible ring created by the tiny, Cassini-discovered moon, Pallene (3 miles, or 4 kilometers, across). The next narrow and easily seen ring inward is the G ring. Interior to the G ring, near the 11 o’clock position, one can barely see the more diffuse ring created by the co-orbital moons, Janus (111 miles, or 179 kilometers, across) and Epimetheus (70 miles, or 113 kilometers, across). Farther inward, we see the very bright F ring closely encircling the main rings of Saturn.
Following the outermost E ring counter-clockwise from Enceladus, the moon Tethys (662 miles, or 1,066 kilometers, across) appears as a large yellow orb just outside of the E ring. Tethys is positioned on the illuminated side of Saturn; its icy surface is shining brightly from yellow sunlight reflected by Saturn. Continuing to about the 2 o’clock position is a dark pixel just outside of the G ring; this dark pixel is Saturn’s Death Star moon, Mimas (246 miles, or 396 kilometers, across). Mimas appears, upon close inspection, as a very thin crescent because Cassini is looking mostly at its non-illuminated face.
The moons Prometheus, Pandora, Janus and Epimetheus are also visible in the mosaic near Saturn’s bright narrow F ring. Prometheus (53 miles, or 86 kilometers, across) is visible as a faint black dot just inside the F ring and at the 9 o’clock position. On the opposite side of the rings, just outside the F ring, Pandora (50 miles, or 81 kilometers, across) can be seen as a bright white dot. Pandora and Prometheus are shepherd moons and gravitational interactions between the ring and the moons keep the F ring narrowly confined. At the 11 o’clock position in between the F ring and the G ring, Janus (111 miles, or 179 kilometers, across) appears as a faint black dot. Janus and Prometheus are dark for the same reason Mimas is mostly dark: we are looking at their non-illuminated sides in this mosaic. Midway between the F ring and the G ring, at about the 8 o’clock position, is a single bright pixel, Epimetheus. Looking more closely at Enceladus, Mimas and Tethys, especially in the brightened version of the mosaic, one can see these moons casting shadows through the E ring like a telephone pole might cast a shadow through a fog.
In the non-brightened version of the mosaic, one can see bright clumps of ring material orbiting within the Encke gap near the outer edge of the main rings and immediately to the lower left of the globe of Saturn. Also, in the dark B ring within the main rings, at the 9 o’clock position, one can see the faint outlines of two spoke features, first sighted by NASA’s Voyager spacecraft in the early 1980s and extensively studied by Cassini.
Finally, in the lower right of the mosaic, in between the bright blue E ring and the faint but defined G ring, is the pale blue dot of our planet, Earth. Look closely and you can see the moon protruding from the Earth’s lower right. Earth’s twin, Venus, appears as a bright white dot in the upper left quadrant of the mosaic, also between the G and E rings. Mars also appears as a faint red dot embedded in the outer edge of the E ring, above and to the left of Venus.
For ease of visibility, Earth, Venus, Mars, Enceladus, Epimetheus and Pandora were all brightened by a factor of eight and a half relative to Saturn. Tethys was brightened by a factor of four. In total, 809 background stars are visible and were brightened by a factor ranging from six, for the brightest stars, to 16, for the faintest. The faint outer rings (from the G ring to the E ring) were also brightened relative to the already bright main rings by factors ranging from two to eight, with the lower-phase-angle (and therefore fainter) regions of these rings brightened the most. The brightened version of the mosaic was further brightened and contrast-enhanced all over to accommodate print applications and a wide range of computer-screen viewing conditions.
Some ring features — such as full rings traced out by tiny moons — do not appear in this version of the mosaic because they require extreme computer enhancement, which would adversely affect the rest of the mosaic. This version was processed for balance and beauty.
This view looks toward the unlit side of the rings from about 17 degrees below the ring plane. Cassini was approximately 746,000 miles (1.2 million kilometers) from Saturn when the images in this mosaic were taken. Image scale on Saturn is about 45 miles (72 kilometers) per pixel.
This mosaic was made from pictures taken over a span of more than four hours while the planets, moons and stars were all moving relative to Cassini. Thus, due to spacecraft motion, these objects in the locations shown here were not in these specific places over the entire duration of the imaging campaign. Note also that Venus appears far from Earth, as does Mars, because they were on the opposite side of the sun from Earth.
This month, we had one of the most successful public events in the history of our club with the 2012 Transit of Venus program at Edgewater State Park in Cleveland on Tuesday, June 5.
We worked with Cleveland State University, Baldwin-Wallace College, the Cleveland Astronomical Society (CAS), and the Ohio Department of Natural Resources Edgewater State Park staff to present a program that provided an opportunity for about 7,000 people to personally use telescopes to observe one of the major astronomical events of this century and of our lifetimes.
I think it’s important to document our transit program here in our newsletter and on our website, and to recognize our members who provided most of the telescopes used at Edgewater State Park to observe Venus during the transit.
CAA member Jay Reynolds, a professional astronomer who teaches at Cleveland State University, personally organized and coordinated the transit program. Here are the major participants who worked with Jay:
Cuyahoga Astronomical Association. CAA members provided most of the 30 or so telescopes that were used for public observations during the June 5 transit, and helped assemble the 5,000 No. 5 optical-grade Mylar solar viewers that were given away to the public. CAA President Bill Murmann participated in planning and supporting the program.
Cleveland Astronomical Society. CAS President Bob Sledz and his wife, Ingrid, worked on the transit project. Bob designed the Mylar solar viewers, which were paid for by a personal donation from CAS member Joanne D. Denko, M.D. CAS members helped assemble the solar viewers, and manned a table during the transit program to distribute the viewers free of charge to the public.
Cleveland State University. CSU’s College of Science, represented by Jay Reynolds, was a major supporter of the Transit program. CSU science students helped with the event.
Baldwin-Wallace College. B-W Observatory Director and CAA member Gary Kader and science students from the college provided telescopes and other support during the program. The college also created and distributed special souvenir bookmarks commemorating the transit.
Ohio Department of Natural Resources. ODNR officials and Edgewater State Park staff provided outstanding support and planning for the transit program. Park Rangers and staff provided extra security, traffic control, and other services that helped make the Transit a great success.
Exhibitors. Ten exhibitors set up information tables for the transit program, including the Cleveland Astronomical Society, the Cleveland Museum of Natural History, the International Women’s Air & Space Museum, the U.S.S. Cod, the Friends of Edgewater, Akron radio station WNIR, Baldwin-Wallace Admissions, Cleveland State Admissions, and the CSU Wolstein Center.
The Natural History Museum’s Observatory Coordinator and CAA member Clyde Simpson and Planetarium Coordinator Jason Davis brought a desktop solar telescope for use at the Museum’s information table.
NASA Glenn Research Center. While not an official exhibitor, NASA Glenn sent their Satellite Truck and Video Projection Truck to show a live video feed of the transit as seen in Hawaii.
News Media Coverage. The transit and CAA received extensive news media coverage before, during, and after the event, thanks to interviews and promotion done by Jay Reynolds. Media coverage included The Plain Dealer, Fox TV 8, WTAM, WNIR, WKYC, WEWS TV, WDOK, and WCPN.
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CAA Telescopes. CAA members who brought their personal telescopes for the public to observe the transit include: Gary Kader, Bob Pence, Jay Reynolds, Bill Murmann, Susan Petsche, Jim Cofer, Tim Campbell, Bill & Carol Lee, Bruce Lane, Lynn Paul, Carl Kelley, Bob Wiersma, Matt Franduto, Steve & Gail Korylak, Steve Spears, Trevor Braun, Suzie Dills, Gus Waffen, Ted Sauppé, and Chris Christe.
Members and others who helped at Edgewater without telescopes include: Steve Gallant, Ron Devine, Kathy Ruffus, Isabel Guadiz-Tobey, and Mary Ann Wadsworth.
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Thanks to the support of our members and other sponsoring organizations and individuals, this was a memorable program. Many thanks to all!