From the Director

Rex
by Rex Parker, Phd director@princetonastronomy.org

Next meeting by Zoom on Feb 09 at 7:30.  We continue to dream of getting back together in Peyton Hall on campus, but for the next few months at least we anticipate running the meeting virtually with Zoom.  The meeting on Feb 09 will feature a guest speaker from Princeton University Astrophysics Dept. – see the section below by Program Chair Victor Davis for more information.

Meanwhile I’d like to reiterate the request for financial contributions to the Gene Ramsey Memorial Reconstruction Fund.  It’s a great way to honor Gene, who did so much for many years for AAAP and especially the Observatory.  For more information please see Assistant Director Larry Kane’s appeal via e-mail sent to all members Jan 16.  Checks to AAAP can be mailed to Treasurer, Amateur Astronomers Assoc. of Princeton, Inc., PO Box 2017, Princeton, NJ 08543. Contributions can also be made electronically via a secure ‘Donate’ button at the end of Larry’s appeal in this issue of Sidereal Times  or by clicking the donate button on the website. Contributions are tax-deductible.  Please consider corporate matching if that is an option for you.

Challenging the paradigm.  At the January meeting we talked about renewed interest in the extrasolar traveler Oumuamua, a quite unusual “cometary” object that swiftly flew in and out of the solar system in late summer 2017.  It was studied by every telescope that could see it for about 11 days before it was gone, including some of the most sophisticated instruments in the world. The data collected are remarkable.  I have been following the story ever since, and members may recall we had a couple of discussions about it at AAAP meetings.  Not surprisingly most professional astronomers interpret Oumuamua, at least publicly, as a highly unusual natural interstellar object. Avi Loeb, noted astrophysicist and among other roles the chair of the Harvard Astronomy Dept. and the Board on Physics and Astronomy of the National Academies, is one of the few with the courage and insight to say that Oumuamua may really be alien tech. 

Dr. Loeb’s new book, Extraterrestrial: The First Sign of Intelligent Life Beyond Earth (Houghton Mifflin Harcourt, publishers) was published January 26.  With strong Princeton connections that will be familiar to AAAP members, the book confronts the age-old question “are we alone?” in a new and exciting way.  Dr Loeb suggests that in 2017 evidence passed through our solar system which answers “no” to the question.   The book shows how the existing paradigm of astronomy and science needs to change, and might be able to, in order to see this question differently.  The astrophysical evidence is provided, examined critically, and interpreted.  The author considers what consequences would follow if scientists gave it the same credence they give to conjectures about supersymmetry, extra dimensions, dark matter, and the multiverse, which have less supporting evidence than Oumuamua provides.  He also asks are we as a civilization ready, if the answer is “no we are not alone”.  This important work is central to the interests of our organization.  So I am challenging AAAP members to read the book for a serious discussion aiming for the March meeting.

Of moths and the milky way.  What’s plaguing the dark skies and astronomy is really bothering the birds, moths, and butterflies, too.  Light pollution and skyglow are obscuring our ability to see ourselves in relation to the cosmos, and most of the global population will never see the Milky Way galaxy we are part of.  And now we are learning that artificial lighting at night is greatly distressing many other animals, especially birds and insects.  Life evolved and flourished on earth over millions of years in rhythm with diurnal/nocturnal light cycles and seasons, but the cadence has been disturbed by excessive artificial outdoor lighting.  Moths and butterflies (the order Lepidoptera) are particularly sensitive to both the intensity and spectral character of artificial light – blue light interferes more than amber-tinted lights.  Artificial light at night confuses adult moths and blocks normal behavior, trapping them in the glow and interfering with their life cycle and reproduction. And many bird species rely on caterpillars for protein and other nutrients. A meta-analysis of the literature was reported by Boyes et al. in 2020 in the journal Insect Conservation and Diversity, Is light pollution driving moth population declines? A review of causal mechanisms across the life cycle. https://onlinelibrary.wiley.com/doi/10.1111/icad.12447

Beyond the direct glare of light fixtures, reflection and scattering of all those photons by ground and atmosphere is perceived by our eyes as skyglow, the background brightness that obliterates all but the brightest stars.  Making it even worse, the installation of energy saving LED outdoor lighting actually worsened the problem initially because atmospheric scattering is greater for the shorter wavelength blue light of early LED’s than it is for the amber colors subsequently developed. 

The degree of light pollution at AAAP’s Observatory at Washington Crossing State Park is likely to get worse with the large scale development now being planned to satisfy the state’s affordable housing dictate.  Fortunately, Hopewell Township has a very good outdoor lighting ordinance, recently updated with a requirement for amber-colored LED’s (color temp. 2700 K or below).  If your town does not have an updated lighting ordinance, ask the municipal leaders to consider the Hopewell ordinance as a model.  The International Dark-Sky Association (IDA) also provides  documents and references for towns and individuals https://www.darksky.org/.  Along with the IDA, the US Naval Observatory in Flagstaff AZ has been at the forefront of the physics and photometric technology to measure light pollution. They discovered the light source color (spectral power distribution) relationship to skyglow brightness, and created the first guidelines for amber LED’s.   

Land preservation, large scale and local, is hugely beneficial to preserving both darker skies and threatened animal species.  Fields of native plants and wildflowers are the most critical habitat for moths and butterflies and their caterpillars, and every acre preserved is one that doesn’t have outdoor lighting.  As amateur astronomers we can urge our friends and neighbors to minimize contributing to light pollution by following a few guidelines:  full cutoff shielding of light fixtures, using the minimum light needed for the task at hand, shutting off outdoor lights before turning in for the night.  Swap your outdoor lights for amber-yellow LED lamps, and eliminate blue-tinted lights that are most harmful to circadian rhythms and dark skies.  It can get worse — yet it can also get better. 

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