How lucky can we be, starting a new year with a full moon — a supermoon no less — on the first day of the year? A supermoon happens when a full moon falls at or very near the moon’s perigee, meaning its nearest brush with Earth, during the month. To add icing to the cake, there will be another full moon on January 31st. That’s a Blue Moon. To have a blue moon and a supermoon in the same month, and to have one on January 1, is rare indeed. Probably a computer could figure out the probability of this kind of lineup, which is so rare it deserves its own color. How about a Mauve Moon?Read More
In 1988, the OMSI Astronomy Club and the Portland Astronomical Society merged. In the coming year, we will be celebrating our 30th anniversary as RCA. Our printed 2018 calendar (on sale now) has a lovely 30th year logo on it and it includes, among the usual awesome imaging done by our very own members, some striking black-and-white photos of astronomy in Portland that goes back well more than thirty years. The strength of interest in astronomy in cloudy, rain-sodden Oregon shows the staying power of hope over experience, doesn’t it?
Banner Design Contest
We need better visual displays! We’ve decided to get three retractable banners printed to use for outreach events. We’re asking imagers to put their wonderful work to good use on what we hope will be stunning banners. Create something beautiful using astronomy images with, at a minimum, our name, logo and our url address. If your design is chosen, we’ll award you with a copy of the book Skyglow. Any member can create a design, but astro-images should be done by an RCA member and have their permission for use. The final size will be 33" x 78." A high-resolution PDF would work well. We’d like to have these ready for next year’s events, so the deadline is Dec. 31 for submitting your entry. To get the logo, contact the president, communications v.p. or the calendar v.p. and we can send you one for incorporation in your creative, attractive, informative, communicative representation of our club.
RCA welcomes Yara Green to the board as our 2018 Vice-President of Outreach and Education. We're also happy to announce that Kathy Kerner, who has been doing such fantastic work on our Twitter and Facebook pages, has joined our Communications Team as our new Social Media Coordinator.
Since Steve Weiler is stepping down after many years of diligent service in his essential role as Observing VP, that position is now open for 2018, so please let us know if you are interested!
The following slate of officers was elected at our November 27 General Meeting:
President: Margaret McCrea
Secretary: Duncan Kitchin
Treasurer: Larry Godsey
VP Membership: Ken Hose
VP Observing: Position Open
VP Outreach & Education: Yara Green
VP Program: Mark Martin
VP Communication: Paul Edison-Lahm
For many moons I’ve been advising RCA members that if they are having trouble with glare from a nearby street light, that they call their local bureau of transportation and tell a representative that “the glare from the street light outside my house is trespassing into my home and I’d like the lamp shielded.” Happily, I’m now able to report on a success story. An RCA member in Portland shared this account of his experience: "Ever since the new street light was installed on our corner lot in Northeast Portland, I've been trying to get it shielded. I was unsuccessful in two earlier attempts. But someone at the last meeting mentioned that the city has changed its policy, so I tried again..."Read More
By RCA Member Charles Fichter
I had the luxury this past year to get out and explore Eastern Oregon and Nevada for observing locations. My extended family lives in Las Vegas, so I made several trips by vehicle and hauled the gear and tents with me to see what I could find, and I purposely diverted further Eastward in Oregon to have a look at a few spots. I was rewarded with several great locations for adventurers with time and hunger to get to really dark skies. Other unexpected treats were in store as well.Read More
This is the story of the imprint of Earth’s orbital cycles on the climate of our planet. Scientists now believe that certain features of Earth’s orbital motions act as a trigger for Earth’s long-term climate cycles, including the cyclical planet-wide glacier cover, popularly called the “Ice Ages” — and termed by science glacial epochs. Scientists first discovered the glacial cycles in the middle of the 19th Century. But the theory linking the glacial epochs to variations in solar radiation caused by cyclical changes in certain of Earth’s orbital motions, had to wait until the first years of the 20th Century.
This is first in a series by RCA Member David Horne.
For hundreds of years, people in northern and central Europe had been noticing large, out-of-place boulders that seemed to have been dropped in a field, or popped up from underground. “Erratics”, they came to be called. Legends attributed the boulders to giants, trolls, and the Devil. By the early 1820s many natural history philosophers, scientists, came to focus on ‘ice’ as the likely mechanism of transport. But the source of all the ice was a mystery.
This is second in a series by RCA Member David Horne.Read More
This is third in a series by RCA Member David Horne. This installment will complete the discussion of Earth’s orbital cycles. We can then turn to the Milankovich Theory, its origins and predictions.
There are three basic cycles involved in Earth’s orbit around the sun: eccentricity, orbital precession, and orbital inclination.
By the mid-1800s a few scientists were beginning to explore a possible relationship between Earth’s orbital cycles and Earth’s Glacial Epochs and Ice Ages. Their first step was to develop a working model linking Earth’s cyclical orbital changes to corresponding changes in the amount of solar radiation received by earth. Among scientists to begin the exploration before Milutin Milankovitch, three are of special importance for this article: Joseph Adhemar, Urbain Le Verrier and James Croll. In fact, the Milankovitch cycles are sometimes referred to as the Croll-Milankovitch cycles.Read More
By 1920, Milankovtich completed the book he began writing during the World War: Mathematical Theory of Heat Phenomena Produced by Solar Radiation. In this work, Milankovtich set out the mathematical tools he developed by which he calculated and described the amount of solar radiation received planet wide on Mars, Earth and Venus. As mentioned in the introduction to this series of articles, his calculations for Mars and Earth proved accurate. But, because he was unaware of Venus’ dense atmosphere his calculations of Venus’ were not even close — spacecraft probes have measured surface temperatures over 850 degrees Fahrenheit and pressures equal to the pressure 3000 feet underwater. The book received more attention from the public for his Mars’ results than it did from geologists interested in Earth’s Ice Ages because in the first decades of the 20th Century, the popular press was filled with stories about Martians and canals on Mars.Read More
The Milankovitch theory identified three aspects of Earth’s orbital motion as causes of the Ice Age glacial periods and the cyclical long term climate change: (1) the changing shape of Earth’s orbit from more circular to more elliptical; (2) cyclical changes in the “tilt” of Earth’s axis of rotation (axial tilt and precession) which affect the amount of solar radiation received by each hemisphere; and (3) the first two aspects acting together to determine where along Earth’s orbit maximum and minimum levels of solar radiation are received. These orbital cycles have always affected Earth’s climate by controlling the amount of solar radiation reaching Earth.Read More
Once again, I’ve received an email from a member of the public with a heart-rending story. Someone has purchased a star name as a gift to someone they love, or in remembrance of someone who has passed away. They write to me to say they can’t find that star and ask me how to find it. Then once again I am tasked with informing a loving and well-meaning person that they’ve been scammed.Read More
Scientists are wading through a trove of data from Saturn and its moons thanks to the discoveries of the Cassini spacecraft, which was intentionally plunged into Saturn's atmosphere in September. Launched in 1997, Cassini reached the Saturn system in 2004 after gravitationally slingshotting around Venus, Earth, and Jupiter. The spacecraft's 12 instruments collected data that revealed oceans of liquid methane on the surface of Titan, Saturn's largest moon, and helped scientists measure the length of a Saturn day, a long-standing mystery.
Artwork by RCA Member Beth Kerner. More of Beth's beautiful illustrations can be viewed here.Read More
The eclipse has come with much fanfare and now it’s over. We’ve invested so much eager anticipation, hard work and excitement into seeing this one that now we’re left wondering what to do next. Here are some ideas:
Process and upload your images. They can go on our Forum, on our Facebook page, in our 2018 calendar and to our Communications Officer, Paul, for use on our website in the future. Also, Dawn is collecting images for a slide show for our September general meeting.
Donate your undamaged solar glasses. At the September meeting, we’ll have a large box to collect used solar glasses. We’ll send them to our friends at Astronomers Without Borders who will donate them to schools and clubs in South American for the 2019 eclipse going over Chile and Argentina.
Image by RCA Member Michael McKeagRead More
The eclipse was incredible! At the present, I am still getting the data logged into this short eclipse report. We rated ourselves in the 95 percentile for statistical efficiency on the performance of the team and the instruments. Some of the gear was not perfected until two hours before totality! Besides our highly efficient team, we also had a Canadian theorist and European Space Agency and Jodrell Bank Radio Telescope researchers helping us. In all, there were about fourteen people assisting us. All five radio telescopes used performed well at CATE site number three, the LEOS, Hercules II and the ICOM, in the UHF, c band, and s band collected data.Read More
by RCA Member Teela Bright
The day started out early as I woke up around 3:00 am, thinking of my incredible luck in having my name drawn by RCA for such a spectacular event — reviewing in my mind the smiles and amazing support I have had from RCA, knowing in my heart that they would all be with me during this flight, and then some — and knowing I have been blessed with perhaps a once-in-a-lifetime chance to see something so amazing and beautiful.
RCA is working together with our friends at Portland Audubon to raise awareness about light pollution. On September 15 turn off your non-essential lights from dusk to dawn, and then to go outside and check out the night sky! Iconic buildings all around Portland will be going lights out to raise awareness about light pollution, including the Fox Tower, the Wells Fargo Tower, OMSI, Bonneville Power Administration, 200 Market, the 911 Federal Building, Montgomery Park, Holladay Park, City of Portland buildings, and 1201 Lloyd! The Lloyd EcoDistrict is cosponsoring the launch event with their own district effort: LightsOut Lloyd PDX.Read More
RCA Volunteers shared their time, telescopes and knowledge with over 1,000 people at the OMSI viewing party for the total eclipse in Salem, OR on August 21. Volunteers showed up Saturday afternoon to help set up and many slept overnight in the gravel lot of the Oregon State Fair Grounds to be ready for Monday’s early morning. With 14 wonderful volunteers, there were many activities to engage the attendees of the event. There were 7 telescopes set up for public viewing of the sun and Venus. There was also an eclipse diagram provided by Robin Baker, an RCA astro-photography display and an Oregon roadmap showing path of totality by Paul Salvatore. Lastly, there were activities for kids of all ages that included UV bead bracelets, moon phase wheels, and solar eclipse word searches.
Many thanks to Robin Baker, Paula Frenchen, Yara Green, Bob Hansen (from sister club in Vancouver, BC), Robert Nelson and family, Mario and Maria Pedraza, Marc Singleton, April South, Mike Sutherland, and Do and Uyen Tran for their enthusiasm and generosity on such a spectacular occasion.Read More
It was billed as the “great American” eclipse, but I’d rather call it the “great global eclipse.” One of my pleasures on Eclipse Day was meeting Graham and Margaret Duhig, members of BDAA, the British Deaf Astronomical Association. I spent the night before the eclipse at a small hotel downtown so I would wake up in the morning close to the train station. When I checked in, I noticed a senior couple signing to each other. The next day as I checked out at 5:15 a.m., the hotel clerk told me I had just missed sharing a taxi with the English astronomers who were here to see the eclipse. When I got to the train station, they were there, so I introduced myself and gave them a card from RCA. They showed me a picture of their group and gave me their contact information. We shared a train ride down and they set up near the capitol steps for the event. There’s more to the story, but I’ll end it by saying I encourage you to visit their website and friend or like them on Facebook.Read More